TK 62061-18-IM-EN
59
Suction Pressure Regulator (SPR) Adjustment
Procedures
IImmppoorrttaanntt:: All new unit installations require these adjustment procedures. Failure to do so may not allow the unit to
operate at its maximum capacity.
NNoottee:: The following procedures are for initial settings. Sometimes conditions such as high or low ambient
temperatures may require that the settings be fine-tuned for optimum performance.
MMAAXX 2200 units are equipped with a SPR valve located in the evaporator (See illustration below). The valve is used to
limit the load on the standby compressor. This also affects the current draw of the electric motor. Monitor the current
drawn of the electric motor when making this adjustment to ensure it is below the motor overload relay setting.
1. Install gauge manifold set onto the suction service port at the standby compressor (See illustration below).
2. Attach an additional compound gauge on suction service port located on copper suction tube in evaporator to
monitor suction pressure going to the SPR valve (See illustration below).
3. Connect clamp on amp meter to T1 (Black) motor wire on a 115V/230V 1 PH unit, or to the leg of the highest voltage
motor wire of a 230V 3 PH unit.
4. Connect standby power receptacle to an appropriate electric power source.
5. Place jumper wire between the 12 and CHB wires at the defrost termination switch to verify the unit will run in
defrost.
6. Start unit and run in defrost on the electric standby compressor until the pressure on the additional compound
gauge attached to the suction service port stabilizes at a pressure above 45 psig (310 kPa).
7. Check the suction pressure on the gauge attached to the suction service port at the standby compressor. It should
be 24 ± 2 psig (165 ± 14 kPa) without exceeding the following electric motor current draws:
Voltage/Phase/Frequency Full Load (amps) Overload Relay Setting (amps)
230/1ph 50/60Hz 20 18
230/3ph 50/60Hz 16 16
400/3ph 50/60 9 10
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