Sterling A0554831 User Manual
2-40 HP Portable Chillers
Chapter 2: Functional Description
14 of 70
2-5 Optional
Features
Options marked with “*” indicate options that can be factory installed or retrofitted in the
field.
field.
Automatic Water Make-Up*. Not available on chillers less reservoir tank. Includes a
pressure-regulating valve set at 3 to 5 psi, an electric water solenoid valve, a float switch
mounted in the reservoir tank, and the necessary internal piping to connect the chiller to a
make-up water source. See Appendix for typical piping diagrams.
pressure-regulating valve set at 3 to 5 psi, an electric water solenoid valve, a float switch
mounted in the reservoir tank, and the necessary internal piping to connect the chiller to a
make-up water source. See Appendix for typical piping diagrams.
Caution! Customer piping must provide backflow protection and venting of tank to
atmosphere to prevent over-pressurization of the reservoir tank. See Central
and Gravity Return Piping with Standpipe Diagram on page 64.
and Gravity Return Piping with Standpipe Diagram on page 64.
Process Water Sidestream Filter*. Not available on chillers less pump and reservoir tank.
Includes a 50 micron filter, flow meter, ball valve for throttling water flow, and the necessary
piping to provide constant filtering of the process water at about one gallon per minute (1
gpm/3.8lpm).
Includes a 50 micron filter, flow meter, ball valve for throttling water flow, and the necessary
piping to provide constant filtering of the process water at about one gallon per minute (1
gpm/3.8lpm).
General Fault Indicator Audible/Visual Alarm*. Includes a 100 dB audible alarm horn/
visual alarm strobe and silence button with provisions for customer wiring indication
interlock. The alarm signals anytime that a fault is recognized during the operation of the
chiller.
visual alarm strobe and silence button with provisions for customer wiring indication
interlock. The alarm signals anytime that a fault is recognized during the operation of the
chiller.
Compressor Hour Meter*. Includes a DIN-mount hour meter that keeps track of the total
time that the compressor runs.
time that the compressor runs.
Communications Options. RS-232C and RS-485 serial communications and remote setpoint
are available.
are available.
Recirculation Pump. Necessary whenever process water flow is less than 2.2 gpm per ton
(8.3 lpm per 3.517 kW) or greater than 4.8 gpm per ton (18.2 lpm per 3.517 kW).
(8.3 lpm per 3.517 kW) or greater than 4.8 gpm per ton (18.2 lpm per 3.517 kW).
High Pressure Fans. Provides for an additional 0.30”WC (75 pa) of static pressure on fan
discharge. High-pressure fans are necessary and must be included in chiller installations
where exiting air exhausts through ductwork.
discharge. High-pressure fans are necessary and must be included in chiller installations
where exiting air exhausts through ductwork.
The fans are available on 5 to 15 hp air-cooled chillers. They can be retrofitted without sheet
metal modification, but will require changing out fan blades, and in some cases, fan motors
and electrical components. 20 hp to 30 hp models come standard with squirrel cage blowers,
which can be ducted.
metal modification, but will require changing out fan blades, and in some cases, fan motors
and electrical components. 20 hp to 30 hp models come standard with squirrel cage blowers,
which can be ducted.
Variable Speed Fan. Available on 5 to 15 hp air-cooled chillers. Reduces the speed of the
fan based on entering air temperature and system load, allowing the chiller to operate in
ambient temperatures below 60ºF (15.5ºC). This option will also reduce fan noise in ambients
below 95ºF (35ºC).
fan based on entering air temperature and system load, allowing the chiller to operate in
ambient temperatures below 60ºF (15.5ºC). This option will also reduce fan noise in ambients
below 95ºF (35ºC).
Crankcase Pressure Regulating (CPR) Valve. Required on chillers operating at leaving
water temperatures from 66ºF to 75ºF (10ºC to 24ºC). This valve prevents compressor motor
overloading.
water temperatures from 66ºF to 75ºF (10ºC to 24ºC). This valve prevents compressor motor
overloading.
Stainless Steel Reservoir. 5 hp to 30 hp models only (Standard on 40 hp models).
Manufactured from 304 stainless steel.
Manufactured from 304 stainless steel.