Nibe CLIMACOOL UCR 30, Installation, Operation & Maintenance Manual

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WARNING!
The troubleshooting guidelines recommended in this
section could result in exposure to electrical safety hazards .
Refer to the safety warnings provided in this manual . Failure
to follow all of the recommended safety warnings provided
could result in death or serious injury . When possible,
disconnect all electrical power including remote disconnects
before servicing . Follow proper lockout-tagout procedures .
Only a qualified licensed electrician or operators trained to
handle live electrical components should only be allowed to
work with energized electrical components .
Troubleshooting Guide
Chiller Will Not Start
Possible Cause Remedy
Power off Check main disconnect switch.
Main Line open Check main fuses.
Incorrect wiring Check the wiring diagram.
Loose terminals/
connections
Tighten the terminal connections.
Control circuit open
Check interlocks with auxiliary equipment,
pressure and temperature controls.
Improper phasing of main
power
Change any two of three phases of main
power.
Compressor Hums But Does Not Start
Possible Cause Remedy
Low voltage
Check at main power entry and power entry at
unit (Consult power company if low).
Phase Loss Check power wiring and fuses.
Compressor Runs But Does Not Cool
Possible Cause Remedy
Improper phasing of main
power
Switch any two of three phases of main power.
Compressor Cuts Out On Low Pressure Safety Control
Possible Cause Remedy
Main chilled water valve
closed or restricted
Open valve to full open position.
Module chilled water
isolation valves, if
provided, closed or
restricted
Open valves to full open position.
Refrigerant shortage Check for leaks - add refrigerant.
No load on water chiller Check water pump operation.
Restriction in liquid line
Plugged liquid line drier - replace liquid
line drier.
Expansion valve clogged
or inoperative
Repair/Replace the expansion valve.
Low discharge pressure
Raise and control discharge pressure within
design limits.
Low water flow through
the cooler
Check water flow through the cooler.
Chilled water temperature
too cold
Raise water temperature setpoint.
Fouled evaporator brazed
plate heat exchanger
Clean-in-place heat exchanger as described
on page 54.
Improper chilled water
circulation
Use an ample sized cleanable strainer in the
chilled water circuit; make certain the strainer
is clean to insure full flow of chilled water
(strainer screen must be 60 mesh minimum).
Faulty suction pressure
transducer
Verify transducer calibration using a calibrated
manifold gauge and replace if defective.
Wrong suction pressure
cutout setpoint
Verify suction pressure cutout setpoint to
be set equal to the corresponding leaving
chilled solution freeze temperature equivalent
pressure on a PT chart. (i.e. if the solution
freeze point is 32°F the equivalent pressure
setpoint will be 101 PSIG).
Compressor Cycles On High Pressure Control
Possible Cause Remedy
Water regulating valve
incorrectly set or defective Reset or replace.
Compressor discharge
valve partially closed
Open valve to full open position.
Non-condensable gases
in hydronic system
Purge non-condensable gases from bleed
valve on condenser or at bleed valve of the
building condenser water system.
Overcharge of refrigerant
Purge refrigerant from system while in
operation until the first sign of bubbles are
shown in the sight glass. Add back refrigerant
just until bubbles clear.
Defective high pressure
switch
Replace high pressure switch.
Causes and Prevention of Freeze-Up
Possible Cause Prevention
Improper charging
Charge per ClimaCool
®
data plate information,
located on the chiller, following the Superheat
and Subcooling procedure described on page
48.
Improper chilled water
circulation
Use an ample sized cleanable strainer in the
chilled water circuit; make certain the strainer
is clean to insure full flow and velocity of
chilled water (strainer screen must be 60 mesh
minimum). It may sometimes be necessary to
treat the water to prevent formation of deposits.
Not draining for winter
shutdown
When the system is shut down for the winter,
remove the drain plugs and drain the cooler.
Blow out remaining water with air.
Faulty leaving chilled
solution temperature
sensor
Verify sensor calibration using a calibrated
thermometer and replace if defective.
Wrong freeze-up
protection temperature
setpoint
Verify leaving chilled solution freeze protection
temperature setpoint to be set at 8°F above
solution freeze point.