GE 2800 Heat Pump Operation Zoneline 3800 and 5800 Series, Zoneline Heat Pump Heat Source Logic

Heat Pumps and Energy Savings

Heat Pump Operation —

Zoneline 3800 and 5800 Series

Heat sources: Heat pump, heat pump and simultaneous electric resistance heat or electric resistance heat.

Zoneline heat pumps employ a highly featured microprocessor control system interfaced with thermistors to accurately measure indoor air temperature, outdoor air temperature, indoor coil temperature and outdoor coil temperature. This system allows the microprocessor to precisely and predictably react to changing conditions in order to provide a very advanced Packaged Terminal Heat Pump operating system.

The Zoneline heat pumps are designed to help ensure a comfortable room. When “HEAT” is selected, the unit will determine if the room air is warm enough to satisfy the thermostat setting. If the temperature at the unit sensor is below the desired temperature, the electric resistance heater will be utilized to warm the room to the point where the thermostat is satisfied. This feature is designed to allow the temperature of an unoccupied room to be maintained at an energy-saving level without inconveniencing the room occupant. Once the thermostat has been satisfied, the resistance heater will turn off and the heat pump will operate as shown in the Heat Source Logic chart until the thermostat calls for heat again. The unit will operate in this manner even if connected to a Central Desk Control.

Zoneline Heat Pump Heat Source Logic

ROOM			Below
TEMPERATURE	Above	Between 46°F
			25°F
VS. THERMOSTAT	46°F	and 25°F
SET POINT
Less Than	Heat Pump	Heat Pump*	Full Resistance
1.8°F Below			Heat
1.8°F to 2.7°F		Heat Pump +	Full Resistance
	Heat Pump	Supplemental
Below			Heat
		Heater
More than 2.7°F	Heat Pump	Full Resistance	Full Resistance
Below		Heat	Heat

*If the “Temperature Boost” switch (dip switch #8) is in the “ON” position the supplemental simultaneous heater will be used with heat pump operation. Simultaneous supplemental heater: 1.0 KW @ 230 V; 0.8 KW @ 208V; 1.0 KW @ 265V.

The “Temperature Boost” option utilizes the supplemental simultaneous heater simultaneously with heat pump operation when the outdoor temperature is below 46°F regardless of the indoor air temperature. The chart above indicates the heat source of the heat pump under various indoor and outdoor conditions. The unit is designed to provide heat pump savings without sacrificing room comfort.

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The Quick Heat Recovery feature is not affected by the Heat Source Logic shown in the chart above. For more information about the Quick Heat Recovery Feature, see page 9. The full heat output of the resistance heater is dependent upon circuit amperage and the power connection kit used. See pages 3 and 42-43 for information on power connection kits and available heater capacities.

A heat pump switch is provided in the auxiliary controls to allow the unit to operate only in resistance heat. The use of this option significantly increases the cost for heating.

Heat pump defrost — Zoneline 3800 and 5800 Series

Zoneline heat pumps utilize a reverse-cycle demand defrost system to extend heat pump operation and increase savings from extended operation. The microprocessor determines the need for defrosting by criteria based

on continuous compressor running time, outdoor air temperature, outdoor coil temperature and the rate of temperature change of the outdoor coil. When defrosting is required, the unit reverses the flow of refrigerant to direct the hot gas into the outdoor coil to melt the frost build-up. Before and after the reverse-cycle defrosting, the unit shuts off the compressor to allow the refrigerant pressures

to equalize throughout the system. This eliminates the possibility of a loud reversing noise. During these periods of pressure equalization, the full resistance heat capacity of the unit is activated to help ensure room comfort conditions during the defrost cycle. The unit remains in the defrost cycle for a minimum of two minutes up to a maximum of nine minutes. The defrost cycle terminates when the outdoor coil reaches a temperature of 68°F or the maximum time has been reached.

Heat pump condensate

See page 34 for information on heat pump condensate. The Zoneline 3800 Series heat pumps may be ordered with a factory-installed Internal Condensate Removal (ICR) system to minimize the amount of condensate water draining from the unit during heat pump operation. The ICR system has proven to be an effective means of minimizing the amount of heat pump condensate dripping from the unit. However, if the requirements of a particular installation will allow no dripping of condensate water from the wall case, the installation of an internal or external drain system is recommended.

Units with ICR may not be installed in seacoast or corrosive environment applications.

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