_making sel-351r recloser controls talk

SCHWEITZER ENGINEERING LABORATORIES 2350 NE Hopkins Court A Pullman, WA A 99163-5603 A USA Phone: (509) 332-1890 A Fax: (509) 332-7990 E-mail: [email protected] A Internet: www.selinc.com

Application Guide Volume III AG2000-06

Making SEL-351R Recloser Controls Talk Building a Voltage Throw-Over Scheme with Two SEL-351R Recloser Controls

Mike Collum

INTRODUCTION

The SEL-351R Recloser Control can be used to develop a voltage throw-over scheme. Schemes of this type are used to monitor the line voltages from two sources and automatically transfer the load to a healthy source during service interruptions. The scheme developed in this application guide is flexible and was developed with two SEL-351R recloser controls. After the settings are understood, they can be modified to fit most customer applications. The discussion in this application guide is not meant to offer a full understanding of the SEL-351R, but to supplement information in the SEL-351R Instruction Manual and Quick-Start Guide. An understanding of MIRRORED BITS™ communications, SELOGIC® control equations, and SEL-351R settings is helpful.

closed open

NormalSource

StandbySource

Load

TXRX

SEL-2815

SEL-351R

TXRX

SEL-2815

SEL-351RMIRRORED BITS

Transmitted OverFiber-Optic Cable

Port 3

(3) (1) (1) (3)

Port 3

(bus)

Figure 1: SEL-351R Voltage Throw-Over Scheme

Figure 1 is an elementary diagram for the SEL-351R voltage throw-over scheme. Each SEL-351R recloser control must have the optional three-phase voltage inputs connected to monitor and detect low source voltage on any phase. Connect the sync PT input Vs on each SEL-351R to monitor one phase of load (bus) voltage.

In the voltage throw-over scheme developed in this application guide, the two controls exchange various pieces of information critical to the throw-over scheme via the MIRRORED BITS communications protocol. SEL offers several cable options ranging from hardwire to fiber optics for the exchange of MIRRORED BITS between the relays. The type of cabling depends on the distance between the controls. With the SEL-2815 fiber optic transceiver, the distance between

2 SEL Application Guide 2000-06 Date Code 20000824

the controls can be just over nine miles! Limit hardwire cable distances, however, to 50 feet with SEL-351R controls on the same ground plane.

GENERAL SETUP

STEP 1 – Apply Level 2 Relay Settings

Apply the highlighted settings listed in the Required Settings section of this application guide to both the normal-source recloser control and the standby-source recloser control. These settings changes have to be made at Access Level 2. Setting changes are required to the numerical setting group, the logic setting group, the text setting group, and a communications port. All Level 2 settings in these groups are listed. However, only the highlighted settings are additional or modified settings. The rest of the settings listed are the factory default SEL-351R settings.

When saving numerical settings, ignore the generated warnings that indicate EZ settings may override some settings changes. While EZ settings do have precedence over some numerical settings, no settings changes suggested in this application guide are affected by the EZ setting routine.

STEP 2 – Review the Following Settings and Customize if Necessary

The following settings in the Required Settings section may need to be customized for each application. These relay settings define the voltage throw-over scheme operation. Default values are given in the Required Settings section and will work for many applications. Review the SEL-351R instruction manual for a detailed explanation of the settings.

50P3P - Overcurrent threshold to block under-voltage transfer 27P1P - Low voltage threshold to initiate under-voltage throw-over 27SP - Low bus voltage threshold for hot line/dead bus reclose qualification when

voltage sync supervision is selected 59P1P - Healthy line voltage threshold for hot line/dead bus reclose qualification

when voltage sync supervision is selected SV1PU - Time delay for normal-source trip in a voltage throw-over operation SV2PU - Time delay for standby-source close in a voltage throw-over operation SV3PU - Time delay for normal-source close in a voltage throw-over operation SV4PU - Time delay for standby-source trip in a voltage throw-over operation 25VLO - Low voltage threshold for sync element operation 25VHI - High voltage threshold for sync element operation 25SF - Slip frequency threshold for sync element operation 25ANG1 - Angle difference threshold for sync element operation SYNCP - Phase Vs input connection for sync element operation TCLOSD - Recloser close time compensation for sync element operation

STEP 3 – Apply Routine Recloser Control Settings at EZ setting level

Make all routine recloser settings at the EZ setting level to set up the traditional recloser functions. The EZ setting level settings configure basic recloser settings such as minimum trip levels, number of recloses, time overcurrent curves, etc. Refer to EZ setting section in the SEL-351R Quick-Start Guide for a detailed explanation.

Date Code 20000824 SEL Application Guide 2000-06 3

STEP 4 – Set Up the SEL-351R Voltage Throw-Over Controls Through the Front Panel

After all settings have been applied, select these options, available through the front-panel interface, for proper operation.

1 Press the AUX 1 button to enable or disable the throw-over scheme. When the AUX 1 LED is illuminated, the throw-over scheme is enabled. Mirrored Bits communication must be established between the controls for the button to work. The scheme can be enabled or disabled from either control. If desired, use a label maker to relabel the AUX 1 button (e.g., relabel as TRANSFER ENABLED – see SEL-351R front panel at the end of this application guide, Quick Reference subsection).

2 Use the CNTRL button on the relay to select the NORMAL/STANDBY local control switch and designate one control to be the normal source and the other control as the standby source. The throw-over scheme only works if one source is selected as the normal source and the other is selected as the standby source.

3 Use the CNTRL button on the relay to select the SYNC CLOSE local control switch. This control option designates whether the normal-source control performs a sync check before automatically closing back on a throw-over scheme reclose. The throw-over scheme only works if both controls are set for the same close option.

4 Use the CNTRL button on the relay to select FAKE SYNC TEST if testing the sync-close logic without a synchronizing voltage input to the relay is desired.

STEP 5 – Install the SEL-351R Controls and Make External Connections

After applying the settings changes and selecting the front-panel control options on both SEL-351R controls, make the external connections as indicated in Figure 1. See the Quick-Start Guide for more installation information.

STEP 6 – Test the SEL-351R Controls for Proper Operation

Test the voltage throw-over scheme and other protective functions to verify proper operation of the controls. Use the Quick-Start Guide for methods of testing traditional recloser functions. Use the functional description below to verify proper operation of the voltage throw-over scheme.

OPERATION

Voltage Throw-Over Scheme Operation (No sync voltage supervision on return to normal)

1 Both SEL-351R controls continuously monitor each phase of voltage. A low voltage transfer requires two system conditions to be satisfied;

a One or more phases of line voltage must drop below the 27P1P setting.

b All phase currents in the normal-source control must be below the 50P3P setting.

When both conditions exist simultaneously for SV1PU time, the normal-source recloser trips. LOW VOLT TRIP is displayed to indicate that the normal-source recloser is in an abnormal state.


2 After the normal-source recloser trips, the standby-source recloser closes SV2PU time later. The display message LOW VOLT CLOSE is displayed to indicate that the standby-source recloser is in an abnormal state.

3 When the voltage becomes healthy on the normal-source recloser for SV4PU time, the standby-source recloser trips (the load again is temporarily without power). The LOW VOLT CLOSE display message is cleared.

4 After the standby-source recloser trips, the normal-source recloser closes after SV3PU time. The LOW VOLT TRIP display message is cleared. The close of the normal-source recloser restores power to the load and completes the voltage throw-over trip/close cycle.

Voltage Throw-Over Scheme Operation (with sync voltage supervision on return to normal)

1 Both SEL-351R controls continuously monitor each phase of voltage. A low voltage transfer requires two system conditions to be satisfied;

a One or more phases of line voltage must drop below the 27P1P setting.

b All phase currents in the normal-source control must be below the 50P3P setting.

When both conditions exist simultaneously for SV1PU time, the normal-source recloser trips. LOW VOLT TRIP is displayed on the display as an indication that the normal-source recloser is in an abnormal state.

2 After the normal-source recloser trips, the standby-source recloser closes SV2PU time later. The display message LOW VOLT CLOSE is displayed as an indication that the standby-source recloser is in an abnormal state.

3 When the voltage becomes healthy on the normal-source recloser for SV3PU time, the normal-source recloser closes if a sync condition exists between the sources or the bus voltage is dead. The LOW VOLT TRIP display message is cleared. It should be noted that the normal-source recloser will wait indefinitely for a sync condition.

4 After the normal-source recloser closes, the standby-source recloser trips after SV4PU time. The LOW VOLT CLOSE display message is cleared. The trip of the standby-source recloser restores the system to normal conditions and completes the voltage throw-over trip/close cycle.

DETAILED EXPLANATION OF THE SEL-351R SETTING CHANGES

The EZ setting level of the SEL-351R control provides the user with a setting routine to set the traditional recloser settings. The voltage throw-over scheme settings cannot be made at the EZ setting level but must be made at access level two. The following paragraphs provide a detailed description only of the setting changes or additions necessary at access level two that provide the voltage throw-over functionality. Other settings at access level two are not discussed and care must be exercised to leave them at the factory default values for proper operation of other functions in the control.


Numeric Settings Explanation

The following numeric setting changes must be made on the normal- and standby-source SEL-351R controls. All of these settings except SV1DO, SV2DO, SV3DO, and SV4DO may be customized to specific installations. Use the SET command to invoke the numeric setting process and make changes only to following settings. As mentioned before, EZ settings do have precedence over some numerical settings. However, no setting changes suggested in this application guide are affected by the EZ setting routine.

50P3P - The overcurrent threshold in secondary amps that blocks a voltage throw-over operation. If the low voltage is due to a customer fault, it is not desirable to transfer to the standby source. 50P3P can be set to off to disable the overcurrent blocking feature.

27P1P - The low line voltage threshold in secondary volts that initiates a voltage throw-over operation.

27SP - The low bus voltage threshold in secondary volts for a dead bus condition. When voltage sync supervision is selected, either the voltages across the recloser must be synchronized or the Vs input voltage must be below this threshold to allow any close.

59P1P - The healthy line voltage threshold in secondary volts for a hot line condition. When voltage sync supervision is selected, either the voltages across the recloser must be synchronized or the Va, Vb, and Vc input voltages must be above this threshold to allow any close.

SV1PU - The time in cycles that a low voltage condition must exist before the normal-source recloser will trip in a voltage throw-over operation.

SV2PU - The time in cycles that the standby-source recloser will wait to close after the normal-source recloser trips in a voltage throw-over operation.

SV3PU - The time in cycles that the normal-source recloser will wait to reclose after one of two conditions is met. The conditions depend on the setup of the controls. If voltage sync supervision is used in a return to the normal feed, SV3PU defines the time to close after healthy line voltages are re-established to the normal-source recloser. Otherwise, SV3PU defines the time to reclose the normal-source recloser after the standby-source trips in voltage throw-over operation.

SV4PU - The time in cycles that the standby source will wait to trip in a voltage throw-over operation after one of two conditions is met. The conditions depend on the setup of the controls. If voltage sync supervision is used in a return to the normal feed, SV4PU defines the time to trip after the normal-source recloser has closed. If voltage sync supervision is not used in a return to the normal feed, SV4PU defines the time to trip after the normal-source line voltages become healthy.

E25 - Set to Y if voltage sync supervision is used in a return to the normal feed. Make the following settings if E25 = Y:

25VLO - The low voltage threshold in secondary volts for sync element operation. The secondary line and bus voltages must be greater than 25VLO for sync element operation.

25VHI - The high voltage threshold in secondary volts for sync element operation. The secondary line and bus voltages must be less than 25VHI for sync element operation.


25SF - The slip frequency threshold for sync element operation in slip cycles per second. The bus and line voltages with respect to each other must be slipping less than 25SF. If the analogy of sync scope were used, 1/25SF would be the number of seconds per revolution of the sync scope hand.

25ANG1 - The maximum allowed phase angle difference in degrees between the bus and line sync voltages for sync element assertion.

SYNCP - The phase of bus voltage the Vs input is sensing.

TCLOSD - The time in cycles that the recloser requires for closing after a command to close has been issued. This timer can be used to compensate for recloser close time during a sync-close condition.

SV1DO, SV2DO, SV3DO, and SV4DO - The drop out delay of the SV1T, SV2T, SV3T, and SV4T SELOGIC variables. Set these equal to 10 cycles for proper scheme operation.

Logic Settings Explanation

The following logic setting changes must be made on the normal- and standby-source SEL-351R controls. These settings require no customizing and will be identical in every installation. Shading indicates additions or changes. Unshaded portions are the factory default settings. Use the SET L command to invoke the logic setting process. Make changes only to the following settings.

TR = 51P1T + 51P2T + 51G1T + 51G2T + 51N1T + 51N2T + 67P2T + 67G2T + 67N2T + 67N3T + 81D1T + PB9 + OC + TMB3B

The TR variable is the trip equation. The shaded portion of SELOGIC must be added. The variable TMB3B is used to trip the recloser during voltage throw-over conditions. Several conditions qualify the assertion of TMB3B. These conditions are fully explained later in this section.

In general, the variable TMB3B is asserted with the timer SV1T to trip the normal source when a low line voltage condition exists on the normal source. TMB3B is also asserted with the timer SV4T to trip the standby source after line voltage has been restored to the normal source. TMB3B can also assert to trip the standby-source recloser through mirrored bit RMB7A if the load is transferred back to the normal-source recloser when the customer bus voltage is dead.

CL = (PB8 * LT4 * LT7 + CC * LT7)*(25A1*LB2+3P59*27S*LB2+!LB2) + /SV2T * LT7 + /SV3T * LT7

The CL variable is the manual close equation. The original logic asserts the CL equation when the close button is pressed (PB8 asserted) or when a close command is received (CC asserted). These manual close attempts are qualified with latch bits LT4 and LT7. The state of latch bit LT4 depends on the front-panel lock position. When the front panel is locked, LT4 is deasserted to prevent front-panel closing. The latch bit variable LT7 is controlled by the HOT-LINE tag logic. All forms of reclosing must be disabled when LT7 is deasserted (HOT LINE tagged condition). HOT-LINE tagging conditions are not programmed into the factory default logic. They must be customized to customer preferences in the field. Two additional


portions of logic have been included in the manual close equation for voltage throw-over operation.

The first portion of logic is added to qualify manual reclosing (PB8 or CC asserted) with a sync condition (25A1 asserted) or hot line/dead bus condition (3P59 and 27S asserted). One of these qualifications must be satisfied when voltage sync supervision has been enabled (LB2 asserted). If voltage sync supervision is not enabled (LB2 deasserted), no manual close qualifications are required.

The other portion of logic provides closing of the normal and standby reclosers in a voltage throw-over operation. The rising edges of time-delayed variables SV2T and SV3T are used to close the recloser under certain voltage throw-over conditions if the variable LT7 is asserted. Which SV variable asserts on a low voltage condition depends on whether the control has been designated as the normal source or the standby source. Many conditions qualify the assertion of SV2T and SV3T. These conditions are fully explained later in this section.

In general, SV2T is asserted to close the control designated as the standby source after the normal-source recloser has tripped on a low voltage condition. The variable SV3T is asserted to reclose the control designated as the normal-source recloser some time after healthy voltage is returned to the normal source.

ULCL = TRIP + !PINF * SW1 + !(LT7 + CLOSE) + !(LT4 + /SV2T + /SV3T + CLOSE + CC + 79CY)

The ULCL variable is the unlatch-close equation. Default programming in the SEL-351R control keeps the ULCL equation asserted under certain conditions to qualify reclosing. The qualifications depend on the position of LT7 and LT4. LT7 deasserts on a HOT-LINE tag condition and consequently prevents all reclosing unless a reclose is in progress (CLOSE is already asserted). LT4 deasserts when the LOCK button is used to lock the front-panel controls and consequently prevents manual reclose attempts through the front panel unless a manual reclose is in progress (CLOSE is already asserted). With LT4 de-asserted, automatic reclose attempts (79CY asserted) and remote reclose attempts (CC asserted) are allowed because ULCL is temporarily de-asserted. The shaded portion of SELOGIC is added to the ULCL equation to also de-assert ULCL on the rising edge of SV2T or SV3T and allow a voltage throw-over close attempt regardless of the front-panel lock position.

79DTL = 67N3T * OLS + (67P1 + 67G1 + 67N1) * TRIP + (!LT2 + !LT7) * (TRIP + !52A) + 81D1T + SV16 + PB9 + OC + TMB3B

The 79DTL equation is the reclose drive-to-lockout equation. Default programming in the SEL-351R control initiates the 79DTL equation for several conditions when automatic reclosing is not desired. TMB3B has been added to the 79DTL equation to prevent automatic reclosing on voltage transfer operations. TMB3B is asserted each time a voltage throw-over trip operation occurs.

79CLS = (25A1 * LB2 + 3P59 * 27S * LB2 + 59A1 * !LB2) * !NOBATT * BCBOK * !DTFAIL

The 79CLS equation is the automatic reclose supervision equation. If 79CLS is asserted when a reclose open interval timer expires, an automatic reclose is attempted. If 79CLS is not asserted when a reclose open interval timer expires, the


SEL-351R control will wait for 79CLSD time (Close Power Wait Time in the EZ settings). If 79CLS does not assert within 79CLSD time, the automatic reclosing cycle is stopped.

The shaded portion of logic has been added to the 79CLS equation to qualify automatic reclose attempts with either a sync condition (25A1 asserted) or a hot line/dead bus condition (3P59 and 27S asserted). These qualifications must be satisfied when sync-close supervision is selected (LB2 asserted). Otherwise, the default portion of the 79CLS equation is used.

SET5 = PB6 * !LT5 * LT4 * ROKA + /RMB1A RST5 = (PB6 * LT5 + PB8) * LT4 * ROKA + \RMB1A + PB9

SET5 and RST5 control latch bit LT5. In the voltage throw-over scheme, LT5 is used to enable or disable the voltage throw-over scheme. The throw-over scheme is enabled or disabled simultaneously on each control through the front panel of either control. When MIRRORED BITS communication between the SEL-351R controls is healthy (ROKA asserted) and the front-panel buttons are not locked (LT4 asserted), the AUX 1 button (PB6) can be pressed to alternately assert and deassert LT5. The position of LT5 is transmitted to the opposite control through MIRRORED BIT TMB1A (RMB1A on the opposite control). When LT5 is asserted, the voltage throw-over scheme is enabled. The Aux 1 button on each control can be relabeled as Transfer Enabled for clarity. A manual close (PB8 asserted) or a manual trip (PB9 asserted) from either control resets latch bit 5 and disables the voltage transfer scheme for safety purposes during manual switching.

SV1 = ROKA * LB1 * LT5 * !RMB2A * RMB3A * !RMB4A * TMB1B * !TMB2B + SV1T * !SV3T * !TRGTR * LT5

The SV1 variable is used in the voltage throw-over logic to assert the variable TMB3B and trip the normal-source recloser on a low voltage condition. The conditions to assert SV1 are listed as follows:

1. Communication between devices OK (ROKA asserted)

2. Control designated as normal source (LB1 asserted)

3. Transfer scheme enabled (LT5 asserted)

4. Other control designated as standby source (RMB2A deasserted)

5. Healthy line voltage on standby source (RMB3A asserted)

6. Standby-source recloser open (RMB4A deasserted)

7. Low line voltage on any phase of normal source and no simultaneous overcurrent condition on normal source (TMB1B asserted)

8. Controls configured properly (TMB2B deasserted)

The low voltage trip timer SV1 starts after all above conditions are satisfied and asserts SV1T when it times out. SV1T is in the TMB3B equation and is used to trip the normal-source recloser. SV1 latches when SV1T asserts and keeps SV1T asserted until the target-reset button is pressed (TRGTR asserted), the SV3T variable asserts, or the voltage transfer scheme is disabled (LT5 deasserts). SV3T asserts to close the normal-source recloser after the voltage becomes healthy again.


SV2 = ROKA * !LB1 * LT5 * !RMB4A * RMB5A * 3P59 + SV2T * !SV4T * !TRGTR * LT5

The SV2 variable is used in the voltage throw-over logic to close the standby-source recloser on a low voltage throw-over condition. The conditions to assert SV2 are listed as follows:


2. Control designated as standby source (LB1 deasserted)


4. Normal-source recloser open (RMB4A deasserted)

5. Normal source previously tripped on low voltage (RMB5A asserted)

6. Healthy line voltage on standby source (3P59 asserted)

The low voltage close timer SV2 starts after all above conditions are satisfied and asserts SV2T when it times out. SV2T is in the close equation to close the standby-source recloser. SV2 latches when SV2T asserts and keeps SV2T asserted until the target-reset button is depressed (TRGTR asserted), the SV4T variable asserts, or the voltage transfer scheme is disabled (LT5 deasserts). SV4T asserts the variable TMB3B to trip the standby-source recloser after the normal-source line voltage becomes healthy again.

SV3 = ROKA * LB1 * LT5 * SV1T * 3P59 * (RMB4A*TMB4B*LB2 + !RMB4A * !LB2)

The SV3 variable is used in the voltage throw-over logic to close the normal-source recloser to restore the system to normal after a low voltage throw-over condition. The conditions to assert SV3 are listed as follows:


2. Control designated as normal source (LB1 asserted)


4. Control previously tripped on a low voltage condition (SV1T asserted)

5. Healthy line voltage on normal source (3P59 asserted)

6. Standby-source recloser closed (RMB4A asserted), voltage sync requirements satisfied (TMB4B asserted) when sync voltage supervision is enabled (LB2 asserted)

Or

The standby-source recloser is open (RMB4A de-asserted) when sync voltage supervision is disabled (LB2 deasserted)

The reclose timer SV3 starts after all above conditions are satisfied and asserts SV3T to close the normal-source recloser when it times out.


SV4 = ROKA * !LB1 * LT5 * RMB3A * SV2T * (RMB4A * LB2 + !LB2)

The SV4 variable is used in the voltage throw-over logic to trip the standby-source recloser to restore the system to normal after a low voltage throw-over condition. The conditions to assert SV4 are listed as follows:


2. Control designated as standby source (LB1 deasserted)

3. Transfer scheme enabled (LT5 enabled)

4. Healthy line voltage on normal source (RMB3A asserted)

5. Control previously closed on a low voltage condition (SV2T asserted)

6. Normal-source recloser closed (RMB4A asserted) when sync voltage supervision is enabled (LB2 asserted)

The trip timer SV4 starts after all the above conditions are satisfied and asserts SV4T to trip the standby-source recloser when it times out.

OUT101 = 27A1 + 27B1 + 27C1 OUT102 = 52A OUT103 = !(LT5*ROKA*!TMB2B)

Output contacts OUT101, OUT102, and OUT103 can be monitored to determine the status of the controls and voltage throw-over scheme. OUT101 will close when the line voltage on any phase of the control is low. OUT102 follows the position of the recloser and closes when the recloser is closed. OUT103 is closed when the voltage throw-over scheme is disabled from the front panel (LT5 deasserted), when communication between the controls is interrupted (ROKA deasserted), or when the controls are not properly configured (TMB2B asserted).

LED6 = LT5*ROKA * !TMB2B

LED6 is the AUX 1 button indicating LED. Pressing AUX 1 alternately asserts and deasserts latch bit LT5. The assertion of latch bit LT5 illuminates LED6 and gives a front-panel indication that the voltage throw-over scheme is enabled. LED6 will only illuminate when relay-to-relay communication is healthy (ROKA asserted) and the controls are configured properly (TMB2B deasserted).

DP1 = LT5*ROKA * !TMB2B DP2 = LB1 DP3 = SV1T DP4 = SV2T DP5 = LB3

The assertion of variables DP1 through DP5 causes various messages to be displayed on the LCD display. See the text settings DP1_1 through DP5_0 to determine what messages are associated with these variables.


ER = /51P1 + /51P2 + /51G1 + /51G2 + /51N1 + /51N2 + /67N3 + /27A1 + /27B1 + /27C1

The rising edges of under-voltage elements 27A1, 27B1, and 27C1 are added to the ER equation to generate event reports at the beginning of a voltage depression. A second event report will be generated if the voltage condition persists long enough to trip the normal-source recloser on a low voltage transfer operation.

TMB1A = LT5 TMB2A = LB1 TMB3A = 3P59 TMB4A = 52A TMB5A = SV1T TMB6A = LB2 TMB7A = (SV3T*27S*LB2+TMB7A)*RMB4A

The SEL-351R controls communicate to each other via an innovative, low-cost, relay-to-relay communications technique that sends internal logic status, encoded in a digital message, from one relay to the other. This new Relay-to-Relay Logic Communications capability, referred to as MIRRORED BITS, opens the door to numerous protection, control, and monitoring applications, such as this one, that would otherwise require more expensive external communications equipment wired through contacts and control inputs. The MIRRORED BITS communications scheme repeatedly sends the status of eight internal relay elements, TMB1A to TMB8A, from one relay to the other, encoded in a digital message. Bidirectional communications, transmit and receive, in each SEL relay, create eight additional “virtual” outputs on each relay “wired” through the communications channel to eight “virtual” control inputs on the other relay. The eight “virtual” inputs, RMB1A to RMB8A, are internal relay elements in the receiving relay that follow, or “mirror,” the respective status of the TMB1A to TMB8A elements in the sending relay. In this voltage throw-over scheme MIRRORED BITS TMB1A through TMB7A transmit information between the controls.

The first six transmit MIRRORED BITS have relatively simple functions. TMB1A asserts to indicate the voltage throw-over scheme is enabled (LT5 asserted). TMB2A asserts when the control is designated as the normal source (LB1 asserted). TMB3A asserts when line voltage is healthy on all three phases (3P59 asserted). TMB4A asserts when the recloser is closed (52A asserted). TMB5A asserts when the normal-source control has tripped on a low voltage throw-over operation (SV1T asserted). TMB6A asserts to indicate the control has sync-close supervision enabled (LB2 asserted).

The operation of TMB7A is more complex. TMB7A asserts to indicate the normal-source control has just issued a close (SV3T asserted) on a dead bus condition (27S asserted). In addition, sync-close supervision must be enabled (LB2 asserted). TMB7A is latched until the standby-source recloser opens (RMB4A de-asserted).

The assertion of TMB7A should only occur following this sequence of conditions;

1. The load has been previously transferred to the standby source due to low voltage on the normal source.

2. Afterward, the bus must lose healthy voltage.


3. Next, the normal-source voltage must become healthy again before the standby source returns healthy voltage to the bus. If these conditions last for SV3PU time, the normal source will close back on a hot line/dead bus condition.

The assertion of TMB7A is used to trip the standby-source recloser quickly when the normal-source recloser closes onto a dead bus. In this situation, it is desirable to trip the standby as quickly as possible to prevent back feeding the standby source from the normal source.

TMB1B = (27A1 + 27B1 + 27C1) * !50P3 TMB2B = (LB1 * RMB2A) + (!LB1 * !RMB2A) + (LB2 * !RMB6A) + (!LB2 * RMB6A) TMB3B = /SV1T + /SV4T + /RMB7A * !LB1 * LB2 TMB4B = 25A1 + LB3 + 27S

The SEL-351R has MIRRORED BITS capability on two channels designated as A and B. Only channel A is necessary for this application. The variables TMB1B, TMB2B, TMB3B, and TMB4B are not transmitted to the other control but are used only as variables in the local device.

TMB1B asserts when the voltage is low on any phase and the recloser does not simultaneously have any phase current above the 50P3P setting. The assertion of the overcurrent element combined with the assertion of the low voltage element is an indication that the source of low voltage is load related. It is not desirable to transfer to the standby source for customer faults. Note that residual overcurrent elements are not used to block a load transfer. It is likely that the loss of one or two phases of source voltage would cause sensitive residual overcurrent elements to assert and incorrectly block a load transfer. Therefore, only phase overcurrent elements are used to block a low voltage transfer. The assertion of this variable is one of several conditions that allow SV1 to start timing for a low voltage transfer.

TMB2B is asserted for several conditions. Each condition is an indication that the throw-over scheme is not configured properly. Improper configuration is detected when either both controls are designated as the normal-source control (LB1 and RMB2A asserted) or both controls are designated as the standby-source control (!LB1*!RMB2A asserted). Improper configuration is also detected when the sync-close conditions on each control do not match. If the local control has sync-close enabled (LB2 asserted) and the remote has sync-close disabled (RMB6A deasserted) or the local control has sync-close disabled (LB2 deasserted) and the remote control has sync-close enabled (RMB6A is asserted), the voltage throw-over scheme is improperly configured. The assertion of TMB2B prevents LED6 from illuminating, display point DP1 from displaying, and SV1 from timing when the controls are improperly configured.

TMB3B is asserted each time a voltage throw-over trip timer asserts to trip the normal- or standby-source recloser. This variable is used for tripping in the TR equation and also the 79DTL equation to disable automatic reclosing on voltage transfer trip operations. SV1T and SV4T are the trip timers that assert TMB3B. Which SV variable asserts on a low voltage condition depends on whether the control has been designated as the normal source or the standby source. SV1T asserts TMB3B to trip the normal-source recloser after a low line voltage condition on the normal source exists longer than SV1PU time. SV4T asserts TMB3B to trip the standby-source recloser when the normal-source line voltage becomes healthy again after a transfer to the standby source has occurred. The mirrored bit RMB7A can


also assert TMB3B to trip the standby-source recloser (LB1 deasserted) when sync-close supervision is enabled (LB2 asserted). See the previous explanation on TMB7A to determine what conditions assert RMB7A.

TMB4B is asserted to allow the normal source to reclose after a previous low voltage transfer when voltage qualifications are satisfied. One of the following three voltage qualifications must be satisfied to allow the normal-source reclose timer SV3 to begin timing.

1. The normal-source line and bus voltages must be in sync (25A1 asserted).

2. The fake sync test must be enabled (LB3 asserted).

3. The bus voltage must be low (27S asserted).

Text Settings Explanation

Make the following text settings changes on the normal- and standby-source SEL-351R controls. These settings require no customizing and will be identical in every installation. Use the SET T command to invoke the text settings process. Make changes only to the following settings.

The first group of text settings assigns labels to local bits. The local bits are local control functions available when the CNTRL button is depressed on the front panel of the SEL-351R. Control functions have been assigned to LB1, LB2, and LB3.

NLB1 = NORMAL/STANDBY CLB1 = STANDBY SLB1 = NORMAL

NLB1 is the text legend for local bit LB1. CLB1 indicates that local bit LB1 will be cleared or deasserted when STANDBY is selected. SLB1 indicates that LB1 will be asserted when NORMAL is selected.

NLB2 = SYNC CLOSE CLB2 = DISABLE SLB2 = ENABLE

NLB2 is the text legend for local bit LB2. CLB2 indicates that local bit LB2 will be cleared or deasserted when DISABLE is selected. SLB2 indicates that LB2 will be asserted when ENABLE is selected.

NLB3 = FAKE SYNC TEST CLB3 = NO SYNC SLB3 = SYNC

NLB3 is the text legend for local bit LB3. CLB3 indicates that local bit LB3 will be cleared or deasserted when NO SYNC is selected. SLB3 indicates that LB3 will be asserted when SYNC is selected.

The second group of text settings assigns labels to display points. The display points are text messages that are displayed when variables DP1 through DP8 are asserted or deasserted. When the variable DP1 is asserted, the text message assigned to DP1_1 is displayed. When DP1 is de-asserted, the text message assigned to DP1_0 is displayed. Display messages have been assigned to DP1, DP2, DP3, DP4, and DP5 to indicate various functions in the controls.


DP1_1 = TRANSFER ENABLED DP2_1 = NORMAL SOURCE DP2_0 =STANDBY SOURCE DP3_1 = LOW VOLT TRIP DP4_1 = LOW VOLT CLOSE DP5_1 = FAKE SYNC

SER Settings Explanation

SER2 = CLOSE 52A CF 79CY 79LO 79RS SH0 SH1 SH2 SH3 SH4 PB8 59A1 SV1 SV1T SV2 SV2T SV3 SV3T SV4 SV4T

SER3 = TOSLP BCBOK DTFAIL TMB1A RMB1A TMB2A RMB2A TMB3A RMB3A TMB4A RMB4A TMB5A RMB5A TMB6A RMB6A TMB7A RMB7A TMB1B TMB2B TMB3B TMB4B ROKA

The SEL-351R can record and time stamp the most recent 512 relay element assertions and de-assertions. Internal elements specific to the voltage throw-over scheme are added to SER2 and SER3 for monitoring and troubleshooting purposes.

Port Settings Explanation

One port on each of the SEL-351R controls must be configured for MIRRORED BITS communication. Port 3 has been selected in this application. Port settings will be identical in both controls with the exception of RXID and TXID, which must be transposed between controls. Use the SET P 3 command to invoke the port 3 setting process. Make changes as follows:

PROTO = MBA

Sets the protocol to channel A MIRRORED BITS.

SPEED = 9600

Sets the baud rate to 9600.

RTSCTS = N

Turns hardware handshaking off.

RBADPU = 60

Sets the amount of time to 60 seconds for the relay word bit RBAD to assert after ROKA deasserts. ROKA deasserts when MIRRORED BITS communication on channel A fails.

CBADPU = 1000

Sets the channel unavailability threshold to 0.1 percent. The relay word bit CBAD will assert if the ratio total channel unavailability to channel availability exceeds 0.1 percent. All communications statistics are available using the COM L command. Relay word bits RBAD and CBAD can be monitored with SCADA if desired.

RXID = 1* TXID = 2*

Sets the transmit and receive addresses for the MIRRORED BITS port.

* These addresses must be transposed between controls.


RXDFLT = XXXXXXXX

Sets the state of received MIRRORED BITS RMB1A through RMB8A to the last good message state when communications are interrupted. It is important to remember the state of the last good message to prevent the voltage throw-over scheme from permanently disabling itself after temporary communications disturbances.

RMB1PU = 2 RMB1DO = 2 RMB2PU = 2 RMB2DO = 2 RMB3PU = 2 RMB3DO = 2 RMB4PU = 2 RMB4DO = 2 RMB5PU = 2 RMB5DO = 2 RMB6PU = 2 RMB6DO = 2 RMB7PU = 2 RMB7DO = 2 RMB8PU = 2 RMB8DO = 2

Sets the message debounce for received MIRRORED BITS RMB1A through RMB8A to two messages. The status of received MIRRORED BITS will change only when two good MIRRORED BITS messages are received sequentially. The bit error rate of the MIRRORED BITS communications channel exceeds IEC-834 recommendations for direct tripping with a two-message count and can be further improved by increasing the message debounce. When the message debounce is increased, the speed at which MIRRORED BITS are interpreted is slowed down.

CONCLUSION

The logic discussed in this application provides a voltage transfer scheme within the SEL-351R recloser control. The logic should be tested before commissioning to verify proper operation. Changes can be made to the logic to meet customer preferences. As a minimum, if setting changes are made to the recommended logic, the new transfer scheme settings should be tested for proper operation in the following scenarios:

1. Check the operation of the transfer scheme during and after the power is cycled to one or both controls. The transfer scheme must be stable for this situation.

2. Communications disturbances should not permanently disable the transfer scheme. Check the transfer logic for proper operation during and after a communications disturbance between the controls.

3. The scheme should operate properly when coordination problems between the normal-source SEL-351R and its upstream device cause the upstream device to trip for customer faults. Presently, the transfer scheme requires the standby recloser to be closed before the scheme can transfer from the standby back to the normal source. This qualification prevents load transfer back and forth between the normal and standby sources for improper coordination. The transfer scheme is halted when the normal-source recloser fails to operate for a customer fault and the standby recloser interrupts the customer fault. (Currently, if both the normal- and standby-source reclosers have coordination problems with upstream devices, the load will be subjected to the full number of upstream reclose attempts of both sources. This occurs because the load is initially transferred to the healthy voltage of the standby source when the normal-source upstream device trips. The standby-source coordination problem causes its upstream device to go to lockout. The normal-source line voltage becomes healthy again after the auto reclose of its upstream device. The load transfer back to the normal source is not prevented because the standby-source recloser never opened for the customer fault.


When the load is transferred back to the normal source, the upstream device will trip and reclose on the customer fault until it goes to lockout. This time, the transfer to the standby source is not allowed because there is no healthy standby voltage. The standby voltage is not healthy because its upstream device has previously gone to lockout for the customer fault.)

4. The scheme should drive the normal-source control to lockout and transfer the load to the standby source when the normal source loses line voltage while the recloser is open and timing to reclose after tripping for a customer fault. If the fault is permanent, the standby source should attempt one reclose and go to lockout.

5. The scheme should disable itself automatically when manual tripping or closing of either control occurs. This will prevent the transfer scheme from improper operation when the scheme has transferred the load to the standby source and someone manually closes the normal-source recloser without disabling the transfer scheme.

6. The transfer scheme should recover from the situation where the controls have swapped the load to the standby source and the standby-source voltage subsequently becomes unhealthy. Make sure the scheme will recover and feed the load from whichever source has its voltage return to healthy first. Currently, logic in the scheme allows for a hot line/dead bus reclose in addition to sync. Also, the standby-source recloser remains closed for loss of line voltage until it is safe to transfer the load back to the normal source.

7. The transfer scheme should not allow itself to be enabled if the controls are configured improperly. The logic should have some self-checking features that are able to catch common configuration errors that might make the scheme operate erratically.

REQUIRED SETTINGS

Settings changes necessary for Voltage Throw-Over Scheme are HIGHLIGHTED.

The highlighted settings changes must be made at ACCESS LEVEL 2. All other settings below are factory default. Make all other recloser control setting modifications at the EZ setting level.

Numerical Group Settings:Numerical Group Settings:Numerical Group Settings:Numerical Group Settings: RID =RECLOSER R1 TID =FEEDER 2101 CTR = 1000.0 CTRN = 1000.0 PTR = 100.0 PTRS = 100.0 Z1MAG = 32.10 Z1ANG = 68.86 Z0MAG = 95.70 Z0ANG = 72.47 LL = 4.84 E50P = 6 E50N = 6 E50G = 6 E50Q = N E51P = 2 E51N = 2 E51G = 2 E51Q = N E32 = N ELOAD = N ESOTF = N EVOLT = Y E25 = Y EFLOC = N ELOP = N ECOMM = N E81 = 6 E79 = 4 ESV = 16 EDEM = THM 50P1P = OFF 50P2P = OFF 50P3P = OFF 50P4P = OFF 50P5P = OFF 50P6P = 0.40 67P1D = 0.00 67P2D = 0.00 67P3D = 0.00 67P4D = 0.00 50PP1P= OFF 50PP2P= OFF 50PP3P= OFF 50PP4P= OFF 50N1P = OFF 50N2P = OFF 50N3P = OFF 50N4P = OFF 50N5P = OFF 50N6P = OFF 67N1D = 0.00 67N2D = 0.00 67N3D = 0.00 67N4D = 0.00 50G1P = OFF 50G2P = OFF 50G3P = OFF 50G4P = OFF 50G5P = OFF 50G6P = 0.10 67G1D = 0.00 67G2D = 0.00 67G3D = 0.00 67G4D = 0.00 51P1P = 0.40 51P1C = A 51P1TD= 1.00 51P1CT= 0.00 51P1MR= 0.00 51P2P = 0.40 51P2C = C 51P2TD= 1.00 51P2CT= 0.00 51P2MR= 0.00


51N1P = OFF 51N1C = 1 51N1TD= 1.00 51N1CT= 0.00 51N1MR= 0.00 51N2P = OFF 51N2C = 13 51N2TD= 1.00 51N2CT= 0.00 51N2MR= 0.00 51G1P = 0.10 51G1C = 1 51G1TD= 1.00 51G1CT= 0.00 51G1MR= 0.00 51G2P = 0.10 51G2C = 13 51G2TD= 1.00 51G2CT= 0.00 51G2MR= 0.00 27P1P = 80.0 27P2P = OFF 59P1P = 104.0 59P2P = OFF 59N1P = OFF 59N2P = OFF 59QP = OFF 59V1P = OFF 27SP = 80.0 59S1P = OFF 59S2P = OFF 27PP = OFF 59PP = OFF 25VLO = 105.0 25VHI = 130.0 25SF = 0.042 25ANG1= 25 25ANG2= 40 SYNCP = VA TCLOSD= 3.00 27B81P= 80.0 81D1P = OFF 81D1D = 6.00 81D2P = OFF 81D2D = 2.00 81D3P = OFF 81D3D = 2.00 81D4P = OFF 81D4D = 2.00 81D5P = OFF 81D5D = 2.00 81D6P = OFF 81D6D = 2.00 79OI1 = 300.00 79OI2 = 600.00 79OI3 = 600.00 79OI4 = 0.00 79RSD = 1800.00 79RSLD= 600.00 79CLSD= 900.00 DMTC = 5 PDEMP = OFF NDEMP = OFF GDEMP = OFF QDEMP = OFF TDURD = 12.00 CFD = 60.00 3POD = 1.50 50LP = 0.05 SV1PU = 120.00 SV1DO = 10.00 SV2PU = 120.00 SV2DO = 10.00 SV3PU = 120.00 SV3DO = 10.00 SV4PU = 120.00 SV4DO = 10.00 SV5PU = 0.00 SV5DO = 0.00 SV6PU = 0.00 SV6DO = 0.00 SV7PU = 900.00 SV7DO = 0.00 SV8PU = 0.00 SV8DO = 0.00 SV9PU = 900.00 SV9DO = 0.00 SV10PU= 0.00 SV10DO= 0.00 SV11PU= 900.00 SV11DO= 0.00 SV12PU= 0.00 SV12DO= 0.00 SV13PU= 0.00 SV13DO= 0.00 SV14PU= 0.00 SV14DO= 0.00 SV15PU= 0.00 SV15DO= 0.00 SV16PU= 0.00 SV16DO= 0.00 OPPH = 2 OPGR = 2 OPLKPH= 4 OPLKGR= 4 OPLKSF= OFF HITRPH= OFF HITRGR= OFF HILKPH= OFF HILKGR= OFF ECOLDP= N ECOLDG= N RPPH = N RPGR = N RPSEF = N ESEQ = N PRECED= N SELSELSELSELOGICOGICOGICOGIC Control Equa Control Equa Control Equa Control Equations:tions:tions:tions: TR =51P1T + 51P2T + 51G1T + 51G2T + 51N1T + 51N2T + 67P2T + 67G2T + 67N2T + 67N3T + 81D1T + PB9 + OC +TMB3B TRCOMM=0 TRSOTF=0 DTT =0 ULTR =!52A PT1 =0 LOG1 =0 PT2 =0 LOG2 =0 BT =0 52A =SW1 * !CLOSE CL =(PB8 * LT4 * LT7 + CC * LT7)*(25A1*LB2+3P59*27S*LB2+!LB2) + /SV2T * LT7 + /SV3T * LT7 ULCL =TRIP + !PINF * SW1 + !(LT7 + CLOSE) + !(LT4 + /SV2T + /SV3T + CLOSE + CC + 79CY) 79RI =TRIP 79RIS =52A + 79CY 79DTL =67N3T * OLS + (67P1 + 67G1 + 67N1) * TRIP + (!LT2 + !LT7) * (TRIP + !52A) + 81D1T + SV16 + PB9 + OC + TMB3B 79DLS =79LO 79SKP =0 79STL =TRIP 79BRS =51P1 + 51P2 + 51G1 + 51G2 + 51N1 + 51N2 + 67N3 + TRIP 79SEQ =79RS * SEQC * (51P1 + 51G1 + 51N1) 79CLS =(25A1 * LB2 + 3P59 * 27S * LB2 + 59A1 * !LB2) * !NOBATT * BCBOK * !DTFAIL SET1 =PB1 * !LT1 * LT4 RST1 =PB1 * LT1 * LT4 SET2 =PB2 * !LT2 * LT4 RST2 =PB2 * LT2 * LT4 + !(79RS + 79CY + 79LO) SET3 =PB3 * !LT3 * LT4 RST3 =PB3 * LT3 * LT4


SET4 =PB5 * !LT4 RST4 =PB5 * LT4 SET5 =PB6 * !LT5 * LT4 * ROKA + /RMB1A RST5 =(PB6 * LT5 + PB8) * LT4 * ROKA + \RMB1A + PB9 SET6 =PB7 * !LT6 * LT4 RST6 =PB7 * LT6 * LT4 SET7 =1 RST7 =0 SET8 =0 RST8 =0 67P1TC=HLP 67P2TC=HTP 67P3TC=1 67P4TC=1 67N1TC=HLG * LT1 67N2TC=HTG * LT1 67N3TC=LT1 * !(51P1 + 51P2 + 51G1 + 51G2 + 51N1 + 51N2) * (!SV12 + SV12 * 50G5 + SV12 * 50N5) 67N4TC=1 67G1TC=HLG * LT1 67G2TC=HTG * LT1 67G3TC=1 67G4TC=1 67Q1TC=1 67Q2TC=1 67Q3TC=1 67Q4TC=1 51P1TC=!SV8 * OCP 51N1TC=!SV10 * OCG * LT1 51G1TC=!SV10 * OCG * LT1 51P2TC=!SV8 + SV8 * 50P5 51N2TC=(!SV10 + SV10 * 50G5 + SV10 * 50N5) * LT1 51G2TC=(!SV10 + SV10 * 50G5) * LT1 51QTC =1 SV1 =ROKA * LB1 * LT5 * !RMB2A * RMB3A * !RMB4A * TMB1B * !TMB2B + SV1T * !SV3T * !TRGTR * LT5 SV2 =ROKA * !LB1 * LT5 * !RMB4A * RMB5A * 3P59 + SV2T * !SV4T * !TRGTR *LT5 SV3 =ROKA * LB1 * LT5 * SV1T * 3P59 * (RMB4A * TMB4B * LB2 + !RMB4A * !LB2) SV4 =ROKA * !LB1 * LT5 * RMB3A * SV2T * (RMB4A * LB2 + !LB2) SV5 =52A * (SV8 + SV10 + SV12) * (RPP + RPG + RPS) SV6 =!52A * (79LO + !79RS * !79CY * !79LO) * (CLP + CLG) SV7 =52A * !50P6 * SV8 SV8 =(SV8 + SV6T) * !(SV7T + SV5T * RPP + !CLP) SV9 =52A * !50G6 * !50N6 * SV10 SV10 =(SV10 + SV6T) * !(SV9T + SV5T * RPG + !CLG) SV11 =52A * !50N4 * SV12 SV12 =(SV12 + SV6T) * !(SV11T + SV5T * RPS + !CLG) SV13 =51P1T + 51P2T + 51G1T + 51G2T + 51N1T + 51N2T + 67P2T + 67G2T + 67N2T SV14 =50G6 + 50N6 SV15 =/SV13 * (OLG * GTP * SV14 + OLG * !GTP * SV14 * !50P6 + OLP * !GTP * 50P6 + OLP * GTP * 50P6 * !SV14) SV16 =SV15 + SV13 * OLP * OLG RCTR =TRIP RCCL =CLOSE OUT101=27A1 + 27B1 + 27C1 OUT102 =52A OUT103 =!(LT5*ROKA*!TMB2B) OUT104=0 OUT105=0 OUT106=0 OUT107=0 LED1 =LT1 LED2 =LT2 LED3 =0


LED4 =!SG1 LED5 =!LT4 LED6 =LT5 * ROKA * !TMB2B LED7 =0 LED8 =52A LED9 =!52A*PINBD LED11 =59A1 LED12 =NOBATT + !BCBOK + DTFAIL LED13 =!LT7 LED14 =TRIP LED15 =51P1T + 51G1T + 51N1T LED16 =67P2T + 67G2T + 67N2T LED17 =81D1T LED18 =79RS LED19 =79CY LED20 =79LO LED24 =50G6 + 50N6 LED25 =67N3T DP1 =LT5 * ROKA * !TMB2B DP2 =LB1 DP3 =SV1T DP4 =SV2T DP5 =LB3 DP6 =0 DP7 =0 DP8 =0 SS1 =PB4 * LT4 * !SG1 SS2 =PB4 * LT4 * SG1 SS3 =0 SS4 =0 SS5 =0 SS6 =0 ER =/51P1 + /51P2 + /51G1 + /51G2 + /51N1 + /51N2 + /67N3 + /27A1 + /27B1 + /27C1 FAULT =51P1 + 51P2 + 51G1 + 51G2 + 51N1 + 51N2 + 67N3 BSYNCH=52A CLMON =0 BKMON =TRIP E32IV =1 TMB1A =LT5 TMB2A =LB1 TMB3A =3P59 TMB4A =52A TMB5A =SV1T TMB6A =LB2 TMB7A =(SV3T*27S*LB2+TMB7A)*RMB4A TMB8A =0 TMB1B =(27A1 + 27B1 + 27C1) * !50P3 TMB2B =(LB1 * RMB2A) + (!LB1 * !RMB2A) + (LB2 * !RMB6A) + (!LB2 * RMB6A) TMB3B =/SV1T + /SV4T + /RMB7A * !LB1*LB2 TMB4B =25A1 + LB3 + 27S TMB5B =0 TMB6B =0 TMB7B =0 TMB8B =0 Text Labels SettingsText Labels SettingsText Labels SettingsText Labels Settings NLB1 =NORMAL/STANDBY CLB1 =STANDBY SLB1 =NORMAL PLB1 = NLB2 =SYNC CLOSE CLB2 =DISABLE SLB2 =ENABLE PLB2 = NLB3 =FAKE SYNC TEST CLB3 =NO SYNC SLB3 =SYNC PLB3 = NLB4 = CLB4 = SLB4 = PLB4 = NLB5 = CLB5 = SLB5 = PLB5 = NLB6 = CLB6 = SLB6 = PLB6 = NLB7 = CLB7 = SLB7 = PLB7 = NLB8 = CLB8 = SLB8 = PLB8 = DP1_1 =TRANSFER ENABLED DP1_0 = DP2_1 =NORMAL SOURCE DP2_0 =STANDBY SOURCE DP3_1 =LOW VOLT TRIP DP3_0 = DP4_1 =LOW VOLT CLOSE DP4_0 = DP5_1 =FAKE SYNC DP5_0 =


DP6_1 = DP6_0 = DP7_1 = DP7_0 = DP8_1 = DP8_0 = 79LL =SET RECLOSURES 79SL =RECLOSE COUNT SER SettingsSER SettingsSER SettingsSER Settings SER1 =TRIP 51P1T 51P2T 51G1T 51G2T 51N1T 51N2T 67P2T 67G2T 67N2T 67N3T 81D1T PB9 67P1 67G1 67N SER2 =CLOSE 52A CF 79CY 79LO 79RS SH0 SH1 SH2 SH3 SH4 PB8 59A1 SV1 SV1T SV2 SV2T SV3 SV3T SV4 SV4T SER3 =TOSLP BCBOK DTFAIL TMB1A RMB1A TMB2A RMB2A TMB3A RMB3A TMB4A RMB4A TMB5A RMB5A TMB6A RMB6A TMB7A RMB7A TMB1B TMB2B TMB3B TMB4B ROKA Port 3 SettingsPort 3 SettingsPort 3 SettingsPort 3 Settings PROTO = MBA SPEED = 9600 RTSCTS= N RBADPU= 60 CBADPU= 1000 RXID = 1 **** TXID = 2 **** RXDFLT=XXXXXXXX RMB1PU= 2 RMB1DO= 2 RMB2PU= 2 RMB2DO= 2 RMB3PU= 2 RMB3DO= 2 RMB4PU= 2 RMB4DO= 2 RMB5PU= 2 RMB5DO= 2 RMB6PU= 2 RMB6DO= 2 RMB7PU= 2 RMB7DO= 2 RMB8PU= 2 RMB8DO= 2

* The RXID and TXID must be alternated between the normal-source and the standby-source SEL-351R controls (normal source RXID=1, TXID=2 - standby source RXID=2, TXID=1). This is the only setting difference between the normal-source control and the standby-source 351.

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Schweitzer Engineering Laboratories 2350 NE Hopkins Court Pullman, WA USA 99163-5603 Tel: (509) 332-1890 Fax: (509) 332-7990

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Quick Reference Distribution Voltage Throw-Over Scheme with Two SEL-351R

Recloser Controls

closed open

NormalSource

StandbySource

Load

TXRX

SEL-2815

SEL-351R

TXRX

SEL-2815

SEL-351RMIRRORED BITS

Transmitted OverFiber-Optic Cable

Port 3

(3) (1) (1) (3)

Port 3

(bus)

Operational Description 1. The controls continuously monitor each phase of voltage magnitude and provide overcurrent protection for the load when closed. When

any one phase of voltage drops below a preset level on the SEL-351R control designated as the normal source and an overcurrent condition does not exist, the normal-source recloser trips after a settable time delay. LOW VOLT TRIP is displayed to indicate that the normal-source recloser is in an abnormal state.

2. After the normal-source recloser trips on a low voltage condition, the standby-source recloser closes after a settable time delay. LOW VOLT CLOSE is displayed to indicate that the standby-source recloser is in an abnormal state.

3. When the normal-source voltage returns to a healthy state, the reclose of the normal-source recloser and the trip of the standby-source recloser depend on the sync-close option that has been selected. If sync-close supervision is enabled, the normal-source recloser will reclose after a settable time delay when a sync or dead bus condition exists and, the standby source will trip after a settable time delay following the normal-source reclose. Note that the normal-source recloser will wait indefinitely for a sync condition before closing. If sync-close supervision is disabled, the standby-source recloser will trip after a settable time delay when the normal-source line voltage becomes healthy (the load again is temporarily without power) and the normal-source recloser will close after a settable time delay following the trip of the standby-source recloser (restoring power to the load).

4. The LOW VOLT TRIP and the LOW VOLT CLOSE display messages are cleared when each source returns to its prior position and completes the voltage throw-over trip/close cycle.

Conditions for Normal-Source Trip on Low Voltage

1. Communication between devices OK 2. Control designated as normal source 3. Other control designated as Standby 4. Transfer scheme enabled 5. Healthy line voltage on Standby 6. Standby recloser open 7. Low voltage on any phase and no overcurrent

condition on Normal Source 8. Controls configured properly

Conditions for Standby-Source Close on Low Voltage 1. Communication between devices OK 2. Control designated as standby source 3. Transfer scheme enabled 4. Normal-source recloser open 5. Normal source tripped on low voltage 6. Healthy line voltage on Standby Source

Low voltage trip timer starts after all above conditions are satisfied and trips the normal-source recloser when it times out.

Low voltage close timer starts after all above conditions are satisfied and closes the standby-source recloser when it times out.

Conditions for Normal-Source Reclose after Low Voltage Trip 1. Communication between devices OK 2. Control designated as normal source 3. Transfer scheme enabled 4. Control previously tripped on a low voltage condition 5. Healthy line voltage on normal source 6. Standby-source recloser closed, voltage requirements

satisfied (sync or dead bus condition) when sync-close supervision is enabled OR Standby source open when sync-close supervision is disabled

Conditions for Standby-Source Trip after Low Voltage Close 1. Communication between devices OK 2. Control designated as standby source 3. Transfer scheme enabled 4. Healthy line voltage on normal source 5. Control previously closed on a low voltage condition 6. Normal-source recloser closed if sync-close

supervision is enabled

Reclose timer starts after all above conditions are satisfied and closes the normal-source recloser when it times out.

Trip timer starts after all above conditions are satisfied and trips the standby-source recloser when it times out.


Quick Reference Distribution Voltage Throw-Over Scheme with Two SEL-351R Recloser Controls

SCHWEITZER ENGINEERING LABORATORIES

The default display indicatesIa, Ib, Ic, In primary currentsand also the following possiblevoltage throw-over schemedisplay messages.

TRANSFER ENABLED NORMAL SOURCE STANDBY SOURCE LOW VOLT TRIP LOW VOLT CLOSE FAKE SYNC

Refer to Definitions Below

Default Display

Operator Controls

Status and TripTarget LEDs

Pushbuttons

1

HOT LINE

TRIP

CLOSE

R

PULLMAN WASHINGTON USA

145 23

SEL-351R RECLOSER CONTROL

GROUPCNTRLSET

EXIT

81CURRENTHIGH

PORT FSERIAL

9

OTHEREVENTS STATUS

TRIPFAST

SELECT

PROBLEMBATTERY

TAG

METERRESET

CANCELTEST

SUPPLYAC

ENABLEDCONTROL

LAMP

TARGET

CURVE

9 8 7 6

SEFGCBLOCKOUT ACYCLERESET

CONTROL STATE FAULT TYPE

196-0325

U.S. Patents 5,041,737 5,208,545 5,317,472 5,349,490 5,365,396, 5,479,315 5,515,227 5,602,707 5,694,281Foreign Patents issued and other U.S. and Foreign Patents Pending

ALTERNATESETTINGS

REMOTEENABLED

RECLOSEENABLED

LOCK(press for 3 sec)

GROUNDENABLED

RELCOSERCLOSED

WAKE UP

AUX 2

RECLOSEROPEN

TRANSFERENABLED

Relabel the AUX 1 button asTRANSFER ENABLED.

When the LED is illuminated,the voltage throw-over schemeis enabled, communicationbetween the SEL-351Rcontrols on Port 3 is healthy,and controls are configuredcorrectly.

Pressing the TRANSFERENABLED alternately enablesor disables the voltage throw-over scheme simultaneously onboth controls.

Disabling the scheme with theAUX 1 button, pressingTARGET RESET, or manualtripping and closing cancels anin-progress voltage throw-overoperation.

AUX 1 Button

1. NORM/STNDBY

2. SYNC CLOSE

3. FAKE SYNC TEST

These setting rules must befollowed:

1. Designate one control as thenormal source and the othercontrol as the standbysource.

2. Sync close option must bethe same on both controls.

3. Use the Fake Sync Testoption only to simplifytesting the voltage throw-over scheme.

Local ControlVoltage Throw-Over

Options

NORMALSTANDBY

DISABLEENABLE

NO SYNCSYNC

1. TRANSFER ENABLED

2. NORMAL SOURCE

3. STANDBY SOURCE

4. LOW VOLT TRIP

5. LOW VOLT CLOSE

6. FAKE SYNC

Voltage throw-over scheme active. Relay-to-relaycommunication healthy. Controls configured properly.

Control is on the normal source to the load.

Control is on the standby source to the load.

Normal-source recloser tripped on low voltage.

Standby-source recloser closed due to normal-sourcevoltage problem.

Fake Sync enabled from local control for testing, mustdisable after testing.

Default Display Message Definitions


All brand or product names appearing in this document are the trademark or registered trademark of their respective holders.

Schweitzer Engineering Laboratories, SELOGIC, Connectorized, and are registered trademarks of Schweitzer Engineering Laboratories.

Copyright © SEL 2000 (All rights reserved) Printed in USA.

Making SEL-351R Recloser Controls Talk SEL Application Guide 2000-06 Date Code 20000824

_making sel-351r recloser controls talk

Documents

r settings

sel application guide

settings changes

numerical settings

ez settings

highlighted settings

modified settings

r voltage throw