York YCAS0130 Eev Troubleshooting, Micro Panel Contents, The system shuts down on Low Superheat

Micro Panel Contents

FORM 201.19-NM1 (204)

8.7 EEV TROUBLESHOOTING

TROUBLESHOOTING

Below are problems and possible solutions or items to check.

●The system shuts down on Low Suction Pressure

·Verify that all refrigerant valves are open.

·Verify that the system is not low on charge.

·Verify that the Expansion Valve Type is set to Elec- tronic.

·Verify that the pilot solenoid is energizing (use Service Mode to manually energize the solenoid coil).

·Verify that the EEV is wired per the elementary dia- gram.

·Verify that the Heat Motor is getting a 24VAC PWM signal. (Use Service Mode to manually energize the EEV output.

·If everything checks out, it is possible that the EEV has failed. If the small charge in the bulb leaks, the valve will not be able to open and the entire EEV must be replaced.

●The system shuts down on Low Superheat

·Verify that the suction temperature sensors are properly installed. They should be located at 4 or 8 o’clock on the suction line. They should not be located near the outlet of the evaporator. They should be installed with copper straps and be well insulated.

·Verify that the suction temperature sensor cables are not swapped between systems (unplugging one sen- sor at a time with the chiller off can verify proper wiring).

·Verify that the EEV heat motor is properly insulated.

·For units with Hot Gas Bypass installed, check that the Hot Gas Bypass valve is set correctly.

·For glycol units, verify that the glycol % is correct.

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