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TM077: 325 & 410 Series II Heat Pump Service Instructions
Rev 00: Issued April 2014
Component Tests 6 and 7
Test 6
Disconnect the element wire from
terminal 5 of the thermostat and using
a multimeter set on the resistance
(ohms) scale, measure between the
two element wires.
Normal resistance for the element is:
1.8kW: 29
Ω – 35Ω
2.4kW: 22
Ω – 26Ω
3.6kW: 15
Ω – 17Ω
Test 7
Fit gauges to the suction (low) side
access valve and observe the suction
pressure.
The suction pressure is dependent on
ambient conditions, however the
suction pressure range is typically
between 200
– 600kPa:
200kPa @ 10°C ambient
600kPa @ 45°C ambient
A suction pressure of less than
200kPa may indicate a refrigerant
leak or a malfunctioning TX valve.
Note: Refer to the Refrigerant Charge
section on page 54 for more
information on refrigerant charge and
refrigerant charge fault indications.
300 kPa
