AEC NEC Central Station Air and Water Cooled Chiller - Manual (Page 23)

Page 22 NEC Series Water- and Air-Cooled Central Chillers
3-4 Galvanic Corrosion
The water circuit piping components are primarily ferrous (iron) and will react electro-
chemically with non-ferrous metallic materials such as copper. Some water has dissolved
minerals that will greatly accelerate the reaction between dissimilar metals.
Use PVC or ferrous piping to minimize galvanic action. If piping must be copper, use dielectric
unions at the chiller.
3-5 Water Treatment
Water treatment is important in any piping system. In some locations, raw water may be used in
the system without problem; in other locations, it will result in large deposits of scale and
corrosion.
AEC, Inc. offers a complete line of water treatment equipment. Contact your AEC, Inc. Sales
Representative for water testing and treatment options.
3-6 Water-Cooled Chiller Condenser Connections
NECW chillers use either city or tower water as a cooling medium. All external condenser
supply and discharge piping and connections should be adequate size.
Two connections are made to each water-cooled condenser:
Condenser Water In
The city or tower water supply inlet is located at the side or rear of the chiller.
• Water pressure ≥25 psi
• Water temperature ≥85°F (29ºC)
Note: NECW condensing pressure with 25 psi, 85°F condenser water in, using R-22:
• 210 psi.
Condenser Water Out
The return outlet, located at the side or rear of the chiller, is connected to a cooling tower inlet, a
sewer or other approved discharge receiver.