21
Installation, Operation & Maintenance - HEH/HEV Series
Ground-Water Heat Pump Applications
Flow Regulation
-
Units without vFlow
®
- Flow
regulation can be accomplished by two methods. One
method of flow regulation involves simply adjusting the ball
valve or water control valve on the discharge line. Measure
the pressure drop through the unit heat exchanger, and
determine flow rate from Tables 8a through 8e. Since the
pressure is constantly varying, two pressure gauges may
be needed. Adjust the valve until the desired flow of 1.5 to
2 gpm per ton [2.0 to 2.6 l/m per kW] is achieved. A second
method of flow control requires a flow control device
mounted on the outlet of the water control valve. The
device is typically a brass fitting with an orifice of rubber
or plastic material that is designed to allow a specified
flow rate. On occasion, flow control devices may produce
velocity noise that can be reduced by applying some back
pressure from the ball valve located on the discharge line.
Slightly closing the valve will spread the pressure drop over
both devices, lessening the velocity noise.
Note: When EWT is below 50°F [10°C], 2 gpm per ton
(2.6 l/m per kW) is required.
Water Coil Low Temperature Limit Setting
- For all
open loop systems the 30°F [-1.1°C] LT1 setting (factory
setting-water) should be used to avoid freeze damage to
the unit. See “Low Water Temperature Cutout Selection” in
this manual for details on the low limit setting.
Summary of Contents for Comfort-Aire Century HE Series
Page 1: ...www marsdelivers com Installation Operation and Maintenance HEH HEV Series...
Page 32: ...32 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram Single Phase Unit...
Page 33: ...33 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram Three Phase Unit...
Page 34: ...34 Installation Operation Maintenance HEH HEV Series Typical Wiring Diagram 460 Volt Unit...