Cooling System Overview Packaged Dx - Greenheck ERCH-20 Installation, Operation And Maintenance Manual

Cooling System Overview
Packaged DX Cooling with Digital Scroll Compressor
8
10
1. Compressor
2. High Limit Pressure Switch
The switch opens when refrigerant pressure
increases above the set point in the liquid line and
it then requires a manual reset.
3. Hot Gas Reheat Valve (optional)
Units equipped with a reheat coil use a three-
way valve with actuator to control the supply
air discharge temperature of the unit during
dehumidification mode. The unit controller provides
a 0-10 VDC signal to control the amount of reheat
to meet the supply temperature set point.
4. Hot Gas Reheat Coil
5. Hot Gas Reheat Check Valve
6. Condenser Fans
7. Condensing Coil
8. Liquid Receiver (optional)
®
6
7
Condenser Airflow
6
5
Supply
Airflow
9 11
3
M
4 12
13
9. Sight Glass
10. Liquid Line Filter Drier
11. Thermostatic Expansion Valve (TXV)
Each unit is equipped with a TXV on each
refrigerant circuit. The valve controls the flow of
liquid refrigerant entering the evaporator coil by
maintaining a constant, factory-set superheat of
10°F. The valve is adjustable and is located on the
side of the evaporator coil and can be accessed
through the inner coil access panel.
12. Evaporative Coil
13. Low Limit Pressure Switch
The switch is installed in the suction line and
disables the DX system when the suction pressure
drops below the set point. The switch will auto-
reset when the pressure rises above the auto-reset
set point.
Energy Recovery Ventilator with Heating and Cooling General Description - NOT model specific
2
1
14
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