Geothermal: Heating
Re: Heating Equipment Operating Conditions
Climatemaster produces a very detailed chart that shows accurate temperatures and refrigerant pressures for different operating conditions.
In order to use this chart, the technician must retrieve and record the following operating data:
1. Check Loop Water
- Pumps
- Use an Amp Probe to check amperage on each loop pump to ensure that they are operating.
- Pumps should start with the compressor.
- Each pump should draw .7 to .8 amps.
- Pressure Drop
- Use a Pressure Gauge to check the water pressure drop through the unit.
- Use performance chart to calculate and record the GPM/Ton.
- No Pressure or Negative Pressure = Low Water
- Temperature Drop
- Use a thermometer to check the water temperature drop across the unit while the compressor is operating at full capacity.
- Check and record the inlet water temperature.
- Check the outlet water temperature.
- Calculate and record the water temperature drop.
2. Check Refrigerant Pressures
- Hook-up refrigerant gauges to the pressure ports on the unit.
- Blue --> "True Suction" Low Pressure
- Red --> High Pressure
- Place an insulated temperature sensor on the liquid line between the evaporator coil and expansion valve.
- Monitor and record the pressures as the system operates.
- Calculate and record the "Sub-Cooling".
- Check "Saturation Temperature" from the discharge pressure gauge.
- Subtract the Actual liquid line temperature reading.
- Saturation Temp - Liquid Line Temp = Sub-Cooling
- (Split-Systems) If a Liquid-Line Sight Glass is installed, observe for bubbles in the sight glass (after the system has been operating for at least 5 min.)
3. Check Air Temperature Rise
- With the auxiliary heaters disconnected (remove "W" from the low voltage terminal block):
- Check the Return Air Temperature near the unit or in the filter compartment.
- Check the Supply Air Temperature.
- Calculate and record the air temperature rise.
- RE-HOOK THE "W" WIRE ON THE CONTROL BOARD.