GP Series Portable Chillers Chapter 3: Installation 18 of 90
3-5 Galvanic Corrosion Considerations
The materials used in the water circuit piping of these chillers are non-ferrous and react
electro-chemically with ferrous metallic materials. Some water has dissolved minerals that
greatly accelerate the reaction between dissimilar metals.
PVC or non-ferrous piping is recommended to reduce galvanic action. If iron piping must be
used, use dielectric unions at the chiller, and water treatment is required.
Note: The use of galvanized piping is discouraged because the rough inside surface
promotes debris to stick and eventually block the flow of the process fluid..
3-6 Water Treatment Considerations
Water treatment is an integral part of the system. In some locations, water may cause large
deposits of scale, erosion, algae, and/or corrosion.
Note: The use of poor quality water may result in inefficient operation, heat
exchanger damage, and pump seal damage. Consult a qualified water
treatment specialist to determine what type of treatment is needed.
3-7 Condenser Considerations
Water-Cooled Chiller Condensers
Water-cooled portable chillers can use city water or tower water as a cooling medium. Make
sure that all external piping and connections supplying and discharging water to and from the
condenser are full size.
You will make two connections to the water-cooled condenser:
Condenser Water In. The condenser water supply is labeled “Condenser Water In. It is the
inlet for city or tower water. For the GPWC20-50, this connection is located near the bottom
of the chiller. For all other sizes this connection is located near the top of the chiller.
Make sure that water is supplied at a maximum temperature of 85ºF (29ºC) and a minimum
pressure of 25 psi.
Caution! The electronic water-regulating valves pressure setpoint is set at the factory.
Only a qualified refrigeration technician should adjust the pressure setting.
Please contact our service group at 800-423-3183 to schedule an appointment.
Normal HFC-410a refrigerant condensing pressure is 342 psi (2,360 kPa), with 85ºF (27ºC)
water at 25 psi entering condenser water pressure
Condenser Water Out. Condenser water return is labeled “Condenser Water Out.” It is the
outlet for water after it has passed through the condenser. For the GPWC20-50, this
connection is located near the bottom of the chiller. For all other sizes this connection is
located near the top of the chiller.
It is connected to the tower water return line or to a sewer or other approved discharge
receiver. A water-regulating valve is a standard feature in the condenser water out line.