Technical information

Page: 28
VL Series Portable Chillers, 2 to 40 Tons UGH021/0301
4.1 SENSORS
A. The sensor is a solid state temperature transducer which converts
temperature input to proportional current output.
B. To quickly test for a defective probe, switch connections between
the defective probe and a probe known to be working properly.
4.2 PROCESS PUMP
A. The centrifugal pump is designed to operate at a specific flow and
pressure at the maximum run load amp draw of the motor. Too
much flow can overload the motor and cause the overload circuit
to open and stop the pump.
B. If the overload trips, check for electrical shorts, loose wires, or
blown fuses. If these check OK, reset the overload circuit and restart
the chiller.
C. Check the amperage and if excessive, partially close the ‘from
process’ valve until the amperage is reduced to the proper level.
4.3 COMPRESSOR
A. Semi-hermetic compressors are protected by an external overload
device (Klixon switch, solid state module, etc.). If the safety switch
opens, this indicates an overload condition exists.
B. Check for electrical shorts, loose wires, bad fuses, or bad motor
starter contacts. If these check ok, check for a defective protection
device.
C. Hermetic compressors have internal protection.
4.4 BLOWER/FAN
A. Check for an electrical short, loose wires, bad fuses, or bad motor
starter contacts.
B. Check the blower for defective bearings or other forms of drag on
the blower wheel.
4.5 LOW FLOW
A. One pump chillers require 100% of the process flow to circulate
through the evaporator.
B. In some process conditions the minimum flow required cannot be
maintained making it necessary to install a bypass line between the
to and from process lines.