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PAPE & OLBERTZ

SCHALTGERÄTE UND WIDERSTÄNDE GMBH

ROTOR STARTERS FOR SLIPRING MOTORS

PAPE & OLBERTZ


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Planning documentation for Pape & Olbertz rheostatic rotor starters For a preselection of a starter for a slipring motor Pape & Olbertz gives the project-engineer the basis for a calculation and selection. The tables and forms are the basis for the first step in a project, but Pape & Olbertz makes the final calculation of the starter. If you don’t find a starter for your problem, don’t hesitate to contact Pape & Olbertz. The power range of our starter ends not in tables but only with the possibilities of Pape & Olbertz. Pape & Olbertz builds starters air- or oil-cooled for motors up to 18000 kW. The starter types OADAK and ODAS comply with the specifications DIN VDE 0660, DIN 46062 and IEC 292-3. Contents I. Oil-cooled rotor starters for three-phase slipring motors II. Starting characteristics of rheostatic rotor starters III. Starter description IV. Instructions for selecting oil-cooled rheostatic starters OADAK (drum type) /

ODAS (contactor type) V. Condition of delivery and sale VI. Table 1.1 Selection table for OADAK with start severity f VII. Table 1.2 Selection table for OADAK with applications VIII. Table 1.3 Selection rotor current and additional equipment for OADAK IX. Table 1.4 Selection table for ODAS with start severity f X. Table 1.5 Selection rotor current and additional equipment for ODAS XI. Table 1.6 Selection for ODAS for centrifugal-pumps VI. Table 1.7 Selection cooling fins for OADAK /ODAS 2.. to 4...U VII. Table 1.8 Selection radiators for OADAK / ODAS 5.. to 8.. Appendix A. Dimension drawings MZ .... B. Standard wiring diagrams ( SF..) for starter type OADAK C. Example wiring diagram for starter type ODAS D. Project sheet for a rheostatic starter calculation

Phone: ++49-(0)2233-96337-0 FAX: ++49-(0)2233-96337-60

Mail: [email protected]

All informations subject to technical changes

PAPE & OLBERTZ


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I. Oil-cooled rotor starters for three -phase slipring motors Rotor starters open up the outstanding features of slipring-motors. Most important is that proportional relation between current-input and torque-output extends close to break-down-torque. As a result, all demands ranging from low-starting-current to extremely powerful acceleration, can be satisfied. The former helps to save gears and power-supplies, the latter means that - together with long acceleration times - even the heaviest loads with high inertia's can be accelerated. Within this rage, a safe solution can be found to nearly every starting question. A further advantage is the fact that most of the waste heat produced in the rotor circuit during starting procedure occurs in the starting resistors, i.e. outside the motor. The following technical features and benefits are significant of oil-cooled rheostatic starters type OADAK (ODAS) and distinguish the latter from other kinds of construction. • Close adaptation to the load characteristics of driven machines by reason of

individual rating and free proportioning of resistance taper for each range of speed. • Free of maintenance requirements for many years, easy to handle, little need for

spare parts. • Low prime cost due to a large variety of models and options yielding best fit to

various of models and options , e.g. optimum design for any power output, severity of start, starting time and starting frequency.

• High class protection, normally IP 54, available up to IP 65.

Furthermore a look into the inside of an OADAK-starter reveals clear and neatly arranged components, without electrical cross-connections in spite of its compact construction. All parts are easily accessible. The heavy steel drum is accurately pivoted. The high life span and reliable functioning is guaranteed by self-cleaning contact studs, the special shape of studs, hardened surfaces and considerable contact pressure. Also the elimination of bouncing and other measures which have been derives from intensive research and development in this field, will be noted.

An additional cost-saving and technically advantageous execution of series OADAK are:

• Twin starters for simultaneous starting of two motors.

Besides, the larger sizes of rotor starters from type OADAK 4..U to OADAK 8...have an oil circulating pump in order to increase thermal safety against overload and to quicken the cooling procedure. Practical tests have shown that cleaning of the starter or change of the oil is not necessary even after having had the starter in use for several years. This is because the oil is not needed to insulate, but only to store heat energy. Normal transformer oil is applied.

PAPE & OLBERTZ


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II. Starting characteristics of rheostatic rotor starters

Severity of start f Average per unit starting current based on full rated current, or appr. the average per unit power input during start based on full rated power input.

N

M

er M

M

I≈= MI

f

For the first estimation of starter size, the typical value of f pertaining to the type of driven machine will be helpful. f = 0.7 : half torque starting typical of driven machines which develop only a low load torque or the load torque of which increases by the square of speed. Also, a low moment of inertia is assumed; e.g. grinding machines. (figure 1.1)

f = 1.0 : fan starting typical of a low load torque, however, in connection with a comparatively high moment of inertia; e.g. exhaust-fan drives. (figure 1.2)

f = 1.25 : appr. full load starting typical of raw mills, cement mills, coal mills. f = 1.4 : full load starting typical of hoists, winches, piston compressors starting under load. (figure 1.3) f = 2.0 : high torque starting typical of crushers, centrifuges. (figure 1.4)

MA = initial torque MB = accelerating torque ML = load torque MLm = average load torque MN = motor rated torque

figure 1.1

figure 1.2

figure 1.4

figure 1.3

MMN

nn0

0 1

0.7

ML

Mm = f

MLm

MA

MB

0,2

MN

MMN

nn0

0 1

MM

Mm= Mn= f 1,0

0,4

MB

Mm

ML

MA

MMN

nn0

0 1

1,4

1,0 MLm= MN

ML

MB

Mm= f

MMN

0

nn

0 1

2,0

1,5

ML

MLm

Mm= f

B

MA

MN 1,0

PAPE & OLBERTZ


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Starting time ta During the starting time ta the current flows through the starter. It corresponds to the duration of the starting process from standstill to rated speed (contacts shorted). For machines with appr. constant load torque you can use the following formula:

MB = accelerating torque = relation torque between starting and load torque GD² = 4 ⋅ J [kpm²] PN = rated power [kW] Number of consecutive starts z Number of starts in succession with the starter initially at ambient temperature and rising to the operating temperature limit, with almost negligible cooling periods inbetween starts, defined as double the starting time. The starter OADAK, ODAS has an thermostat this is generally used as a lock-out device. Hereby exceeding of the permissible number of starts is safely avoided. Starting energy W During the starting period the starter absorbed the starting energy W. It may be derived as

aN tfP5,0 ⋅⋅⋅=A (for one start) [kJ]

aN tzfP5,0 ⋅⋅⋅⋅=W (for z starts) [kJ] The indication of the maximum permissible value of W for each starter size in the following selection tables enables choosing the required starter size. Permissible number of starts per hour h The number of permissible periodical starts or operation cycles per hour. When the starter reaches the maximum operating temperature an interruption for cooling is necessary before carrying out one further start. This cooling period tp is calculated by

htP

60= (in minutes).

Characteristic rotor resistance k

erI⋅=

3

Uk er [Ω ]

[s] P10365,0

GDt

N6

22

aBM

n

⋅⋅⋅⋅

=

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III. Starter description A starter OADAK, ODAS consists of: • oil tank with oil level indicator and outlet valve • a compartment with a resistor-part and contact-drum (OADAK) fastening under a

lid • the control (and power contactors for ODAS) and the rotor cable terminal block is

on top of the lid under a sheet-steel hood or in a switch-cabinet • the resistor-part consists of only AEG-Resistor grids • protection class IP 54 • the 2-K paint corresponds to RAL 7032; other colours on request • Control voltage: 3 x 400 V, 50 Hz and 230 V, 50 Hz or

3 x 440 V, 60 Hz and 230 V, 60 Hz ; other voltages on request. • a remote control and also an emergency handwheel (OADAK) • thermostat F3 and F31 (and F4 for OADAK 4..U to OADAK 8) for temperature

monitoring • step-time-monitor (OADAK) • oil-circulating pump for OADAK 4...U to OADAK 8... • contacts tungsten-tipped (for h > 2 or P > 3000 kW)(OADAK) Additional equipment: • auxiliary switches • thermostat • anti-condensation-heater • oil-level-switch • locked-rotor-control (rotor frequency control) • cable glands for rotor cable and control cable • FLS-packet: contactor, auxiliary switches, cable glands, anti-condensation-heater

and control transformer • for raising the periodic starts h , cooling fins or radiators PAPE & OLBERTZ deliver the starter without oil-filling and stator switch gear!

PAPE & OLBERTZ


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IV. Instructions for selecting oil-cooled rheostatic starter OADAK (drum type) / ODAS (contactor-type) The size of the starter must be selected to the motor characteristics (P, Ier, Uer) and the starting characteristics (f, ta, z, W and h). The characteristics specified in the tables are maximum values and these values must not exceed without to contact Pape & Olbertz. 1. Selecting a drum-type oil-cooled rheostatic starter type OADAK: The former has three possibilities for a calculation/selection:

a. calculation of the starting energy W ⇒ selection the size in table 1.1 with the heat capacity;

b. selection with the data P and f the starter size in table 1.1 in view of the starting time ta;

c. selection with the data P and the drive application in table 1.2.

Example: Application: Ball-mill (f = 1.3) P = 2000 kW Ier = 960 A ta = 18 s z = 3 h = 1 a. W = 0.5 ⋅ P ⋅ f ⋅ z ⋅ ta = 70200 kWs ,

with this heat capacity in table 1.1 the starter size is OADAK 54..

b. With the information of the power P and the starting severity f = 1,4 the correct starter size according to the table 1.1 and a longer starting time

ta = 32 sec is OADAK 64..

c. With the application Ball-mill drive and the rated motor power P you will also find the starter size OADAK 64.. in table 1.2 .

Now you can select the standard starter size with the rotor current of 1120 A in table 1.3. You need the 1200 A size, so that the starter size is now OADAK 5412 or OADAK 6412.

PAPE & OLBERTZ


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You'll find all technical data in the column for the size in table 1.1. You'll also find the number for the dimension drawing and the control wiring number of the standard execution. By example the data for OADAK 6412: z = 3; h = 0,35; weight = 1000 kg and you need 1360 ltr. Oil. But for these example you need h = 1. You'll find the data and the extension for the starter size in table 1.1 and table1.2 in the columns under size for h = 1. The starter size is now OADAK 64 12 R14. The starter needs a tank with radiators (14 elements). For an execution for h = 2:

with table 1.8 and the size OADAK 6... you select the radiators size R 28 with the coefficient 5.8. The price is shown in the same row. The starter size is now OADAK 6412 R28.] The selection/calculation for the sizes OADAK 1.. to 4...U is the same, but you need cooling fins (table 1.7).

Tip: Select the motor with the lowest rotor current!

71.535,02

h

ha

set

real ===

PAPE & OLBERTZ


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2. Selecting a contactor-type oil-cooled rheostatic starter type ODAS: The former has two possibilities for a calculation/selection:

a. calculation of the starting energy W ⇒ selection the size in table 1.4 with the heat capacity;

b. selection with the data P and f the starter size in table 1.4.

Example: P = 300 kW Ier = 365 A f = 1 ta = 15 s z = 3 h = 1 a. W = 0.5 ⋅ P ⋅ f ⋅ z ⋅ ta = 6750 kWs ,

with the heat capacity in table 1.4 the starter size is ODAS 24-...

b. With the rated power of the motor P and the start severity f you'll also find the starter size ODAS 24-... in table 1.4 .

Now you can select the standard starter size with the rotor current of 365A in table 1.5. You need the 370 A size, so that the starter size is now ODAS 24-370/6. You'll find all technical data in the column for the size in table 1.4. You'll find also the number for the dimension drawing of the standard execution. Data for ODAS 24-370/6: z = 3; h = 1,2; weight = 125 kg and you need 100 ltr. Oil. For an execution for h = 2:

with table 1.7 and the size ODAS 2... you select the fins size R 1 with the coefficient 2.

Tip: Select the motor with the lowest rotor current!

67.12.1

2h

ha

set

real ===

PAPE & OLBERTZ


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V. Conditions of sale and delivery The standard term of delivery is ex works, excluding packing, excluding customs fees and import taxes. Other terms on request. Pape & Olbertz deliver the starter without oil-filling and stator switch-gear. Pape & Olbertz reserve the right to adjust the prices and the technical data. The prices base on buying one unit, for more units ask Pape & Olbertz for other conditions.

PAPE & OLBERTZ


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Appendix A.: Dimension drawings MZ.. § MZ 1495

§ MZ 1507

§ MZ 1553

§ MZ 1556

§ MZ 1571

§ MZ 1614

§ MZ 1615

§ MZ 1630

§ MZ 1631

§ MZ 1632

§ MZ 1633

§ MZ 1634

§ MZ 1691

§ MZ 1693

§ MZ 1695

§ MZ 1704

§ MZ 1721

§ MZ 1733

§ MZ 1760

§ MZ 1761

§ MZ 1830

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Appendix B.: Standard wiring diagram (SF..) for starter type

OADAK

§ SF 120

§ SF 158

§ SF 167

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Appendix C.: Example wiring diagram for starter type ODAS

§ S 1 DAS 117

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Appendix D.: Project-sheet for a rheostatic-starter calculation For a calculation of a rheostatic starter Pape & Olbertz need the following data: Rated motor power P [kW] (X): Rotor voltage at standstill Uer [V] : Rotor current at full load Ier [A] (X): Rated motor speed nn [rpm]: Motor pull-out torque: Total moment of inertia related to motor speed GD² [kpm²]: Type of driven machine (X): Load torque plotted against speed: Number of consecutive starts z: Permissible number of starts per hour h: The starter do you need for your drive can Pape & Olbertz now exactly calculate with these data. For the first step at a project Pape & Olbertz need only the data marked with (X). If you have any questions referring to calculation, technology or other products of our delivery scope, please contact our technical department Herr Legrand Tel. + 49(0)2233/96337-33 Herr Althaus Tel. + 49(0)2233/96337-34 Herr Bauer Tel. + 49(0)2233/96337-31 Phone: ++49-(0)2233-96337-0

FAX: ++49-(0)2233-96337-60 Mail: [email protected]

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