ACCESSORY KIT INSTALLATION MANUALLOW AMBIENT PRESSURE SWITCH KIT MODEL (S1-2LA06700224 & S1-2LA06700424)

FOR MODELS: SINGLE STAGE SPLIT SYSTEM AIR CONDITIONERS AND HEAT PUMPS

GENERAL INFORMATIONThe low ambient pressure switch kit S1-2LA06700224 for R-22models and S1-2LA06700424 for R-410A models) aredesigned to regulate condenser liquid pressure at low outdoorambient temperatures by controlling the airflow over the con-denser. The low ambient pressure kit will energize the outdoormotor when the liquid line pressure reaches 300 +/-10 PSIG forR-22 models and 360 +/-10 PSIG for R-410A models, it will stopthe motor when the pressure falls below 150 +/- PSIG for R-22models and 240 +/- PSIG for R-410A models.The supplied relay has a normally-closed contact. As the liquidpressure falls below the low setting of the pressure switch, therelay will energize and open the normally-closed contact, thusbreaking the circuit of the fan motor, causing it to stop. As theliquid pressure increases above the high pressure setting of thepressure switch, the relay will de-energize and close the nor-mally-closed contact, re-energizing the fan. Heat pumps usethe 4-way reversing valve power for the control circuit of the lowambient kit in the order to disable low ambient fan cycling in theheat mode.When applying this kit, a TXV must be used on the indoor coiland a crankcase heater should be added. This will guardagainst liquid migration and hard starts which could lead to pre-mature failure of the compressor.When properly applied, this kit permits operation in coolingmode in low ambient conditions down to +20°F (-7°C).

PRE-INSTALLATION INFORMATION AND INSTRUCTIONS

1. With this kit, only use motors that are single phase, perma-nent split capacitor type, shaded pole, or single speed ECMmotors.

2. Line Voltage Range: 120 to 600 Volts AC.3. Wiring must comply with all local and national electric

codes.4. Crankcase heater should be applied in conjunction with this

kit.

INSPECTIONThe following list details the parts included in this kit. Inspectthe kit to ensure that all the parts are included.

INSTALLATION (S1-2LA06700*24 ALL MODELS WITH PSC OUTDOOR FAN MOTOR)

1. Disconnect power to the unit.2. Remove the control access panel.3. Locate the liquid line base valve and remove the cap off the

schrader valve.4. Attach the tee fitting and pressure switch to the liquid line

base valve, as shown in Figure 1.5. Tighten all connections using a 9/16” wrench. Check the

connections between the switch and schrader valve forleaks.

6. Route the pressure switch wires through the grommetlocated on the bottom of the control box. Secure the wiresaway from hot refrigerant lines with a wire tie.

7. Secure the relay with #10 screws included in the kit. Use therelay to mark and drill two (9/64 inch) holes so that the relayis 1/2 inch away from high voltage wiring and components.

8. To wire the low ambient pressure kit:a. For 1 and 3 phase AC, use Figure 4 - 5*.b. For 1 and 3 phase HP, use Figure 8 - 10*.

*To connect wires to “O” and “C” in the low voltage box, cut offwire connections from the additional black wires provided in kitand strip insulation from wire. Use existing wire nuts to connectinto “O” and “C” junction.9. Replace the control access panel and restore power to the

unit. 10. With the unit running in the cooling mode, make sure the

outdoor fan operates properly and replace all schradervalve caps.

WARNINGImproper installation, adjustment service, or maintenance cancause injury or property damage; therefore, only a qualifiedinstaller or qualified service personnel should perform theconversion.

TABLE 1: Source 1

ITEM QTY. DESCRIPTION1 1 Pressure Switch2 1 Relay3 2 Black Wire4 1 Black Wire5 2 Screw #10-16x3/86 2 Wire Tie7 1 Tee Fitting8 1 Line Splice Connection

!

WARNINGMake sure the electric power is shut-off. Failure to disconnectthe electric power could result in electric shock and severeinjury from the outdoor fan.

FIGURE 1: Pressure Switch Assembly

!

TO

LO

W V

OLTA

GE

BO

X

PRESSURESWITCH

FLAREFITTING

TEE FITTINGASSEMBLY

VALVECAP

FLARE FITTINGWITH DEPRESSOR

BRASS REFRIGERANTVALVE (Liquid)

Johnson Controls Ducted Systems 513433-UAI-E-0120

513433-UAI-E-0120

INSTALLATION (S1-2LA06700*24 ON MOD-ELS WITH ECM FAN MOTOR.)

1. Disconnect power to the unit.2. Remove the control access panel.3. Locate the liquid line base valve and remove the cap off the

schrader valve.4. Attach the tee fitting and pressure switch to the liquid line

base valve, as shown in Figure 1.5. Tighten all connections using a 9/16” wrench. Check the

connections between the switch and schrader valve forleaks.

6. Route the pressure switch wires through the grommetlocated on the bottom of the control box. Secure the wiresaway from hot refrigerant lines with a wire tie.

7. Secure the relay with #10 screws included in the kit. Use therelay to mark and drill two (9/64 inch) holes so that the relayis 1/2 inch away from high voltage wiring and components.

To wire the low ambient pressure kit:a. For 1 and 3 phase AC, use Figure 2 - 3b. For 1 and 3 phase HP, use Figure 6 - 7

*To connect wires to “O” and “C” in the low voltage box, cut offwire connections from the additional black wires provided in kitand strip insulation from wire. Use existing wire nuts to connectinto “O” and “C” junction.

8. Remove fan motor BLU 24VAC COM wire from contactorcoil or defrost board relay and connect to pin #7 on the LAKrelay as shown in diagrams.

9. Locate black wire (included with kit) that contains a piggy-back quick disconnect connector and install on the 24VACcontactor coil COMMON connection or defrost control relaywhere the BLU 24VAC COM wire was removed. Connectthe other end to pin #1 on the LAK relay.

10. For A/C models, locate black wire (included with kit) andconnect one end to the piggyback quick disconnect terminalon 24VAC contactor coil COMMON connection and connectother end to terminal “A” on LAK relay. For HP models, useone of the included black wires and connect one end to ter-minal “A” on LAK relay. Cut the connector off of the oppositeend of the wire and connect it to the unit low voltage “O”connection per diagrams.

11. For A/C models, remove YEL/PNK or YEL 24VAC pressureswitch wire from contactor coil. Connect LAK pressurecycling switch wire that contains a piggyback quick discon-nect connector to this contactor coil connection. Connectthe YEL/PNK or YEL 24VAC wire to the piggyback connec-tor. For H/P models cut the piggyback quick disconnect con-nector off of the pressure cycling switch. Connect it to theunit low voltage “COMMON” connection per diagrams.

12. Connect remaining 24VAC BLK wire from LAK pressurecycling switch to terminal “B” on LAK relay.

WARNINGMake sure the electric power is shut-off. Failure to disconnectthe electric power could result in electric shock and severeinjury from the outdoor fan.

!

2 Johnson Controls Ducted Systems

513433-UAI-E-0120

WIRING DIAGRAMS

FIGURE 2: Wiring Diagram - Low Ambient - Single Stage AC - ECM Motor - Three Phase

Johnson Controls Ducted Systems 3

513433-UAI-E-0120

FIGURE 3: Wiring Diagram - Low Ambient - Single Stage AC - ECM Motor

4 Johnson Controls Ducted Systems

513433-UAI-E-0120

FIGURE 4: Wiring Diagram - Low Ambient - Single Stage AC - PSC Motor - Three Phase

Johnson Controls Ducted Systems 5

513433-UAI-E-0120

FIGURE 5: Wiring Diagram - Low Ambient - Single Stage AC - PSC Motor

6 Johnson Controls Ducted Systems

513433-UAI-E-0120

FIGURE 6: Wiring Diagram - Low Ambient - Single Stage HP - ECM Motor -Three Phase

Johnson Controls Ducted Systems 7

513433-UAI-E-0120

FIGURE 7: Wiring Diagram - Low Ambient - Single Stage HP - ECM Motor

8 Johnson Controls Ducted Systems

513433-UAI-E-0120

FIGURE 8: Wiring Diagram - Low Ambient - Single Stage HP - PSC Motor - 208-230 - Three Phase

Johnson Controls Ducted Systems 9

513433-UAI-E-0120

FIGURE 9: Wiring Diagram - Low Ambient - Single Stage HP - PSC Motor - 460 - Three Phase

10 Johnson Controls Ducted Systems

513433-UAI-E-0120

FIGURE 10: Wiring Diagram - Low Ambient - Single Stage HP - PSC Motor

Johnson Controls Ducted Systems 11

NOTES

Subject to change without notice. Published in U.S.A. 513433-UAI-E-0120Copyright © 2020 by Johnson Controls. All rights reserved. Supersedes: 513433-UAI-D-0917

York International Corp.5005 York Drive

Norman, OK 73069