6-Pack Relay Board

This device is a cluster of 6 pilot relays located in the control center. It is energized by the PSIO for the oil pump, oil heater, alarm, optional hot gas bypass relay, and motor cooling solenoid.

8-Input Modules

One optional module is factory installed in the control center panel when ordered. There can be up to 2 of these modules per chiller with 8 spare inputs each. They are used whenever chilled water reset, demand reset, or reading a spare sensor is required. The sensors or 4 to 20 mA signals are field-installed.

The spare temperature sensors must have the same temperature/resistance curve as the other temperature sensors on this unit. These sensors are 5,000 ohm at 75 F (25 C).

Oil Heater Contactor (1C)

This contactor is located in the power panel and operates the heater at either 115 or 230 v. It is controlled by the PIC to maintain oil temperature during machine shutdown.

Oil Pump Contactor (2C)

This contactor is located in the power panel. It operates all 200 to 575-v oil pumps. The PIC energizes the contactor to turn on the oil pump as necessary.

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Carrier PC211 specifications Pack Relay Board