HEAT PUMP - HEATING CYCLE

HEAT PUMP - HEATING CYCLE
As in the cooling mode, the proper method of insuring that
the system is properly charge is by weight with the additional
charge adjustments for line size, line length, and other system
components as previously indicated.
Hot Gas Method
The following procedure can be employed as a method to check
for system charge in the heating mode by measuring the hot
discharge gas at the compressor.
1. Allow the system to operate at least 20 minutes.
2. Attach and insulate an electronic thermometer's probe
to the vapor service valve (large line) at the base valve.
NOTE - Make sure that the probe is well insulated from
the outdoor air.
3. Allow the system to operate at least 10 minutes.
Afterwards, use an accurate electronic thermometer to
measure the temperature of the discharge gas at the
probe.
4. Using the electronic thermostat, measure the outdoor
ambient temperature.
5. For check purposes the temperature measured on the
hot gas line should be equal to the outdoor ambient
temperature plus 110°F (+ or-4°F). e.g: Outdoor Ambient
45°F then the temperature measured by the
thermometer's probe should be 155°F for a system that
is properly charged. If the temperature measured by the
thermometer's probe is higher than the outdoor ambient
plus 110°F, the system charge should be adjusted by
adding refrigerant to lower the temperature. If the
temperature measured is lower than the outdoor ambient
plus 110°F, the system charge should be adjusted by
recovering charge to raise the temperature