Troubleshooting Guide - Carrier 16JT Series Start Up & Operation Manual

PROBLEM/SYMPTOM
Machine Will Not Start or
Shuts Down
(Panel RUN light out,
pumps off.)
Leaving Chilled Water Temperature
Too High
(Machine running, chilled water
temperature above design.)
Leaving Chilled Water
Temperature Too Low
(Machine running, chilled water
temperature below design.)
Leaving Chilled Water Temperature
Fluctuates
(Machine running, capacity
control hunting.)

TROUBLESHOOTING GUIDE

PROBABLE CAUSE
No power to control panel
Control panel fuse blown
Control panel main circuit breaker open
Control panel switches not set correctly
Chilled water or condensing water pump
overloads or flow switches open
Solution pump overloads open
Refrigerant pump overloads open
Low temperature cutout
High generator solution temperature
or pressure, high absorber pressure.
Steam control valve not open
Set point too high
Excessive cooling load (machine
at capacity)
Excessive chilled water flow
(above design)
Low condensing water flow (below design) Check pressure drop per selection data and reset flow.
High supply condensing water
temperature (above design)
Low steam pressure (below design)
Inadequate steam condensate drainage
(condensate backs up into tube bundle)
Fouled tubes (poor heat transfer)
Machine needs octyl alcohol
Noncondensables in machine
Capacity control malfunction
Solution crystallization
(solution flow blockage)
Low refrigerant level
Cycle-Guard control malfunction
(low solution concentration)
Set point too low
Capacity control malfunction
Chilled water flow or load cycling
Condensing water flow or temperature
cycling
Steam pressure cycling
Inadequate steam condensate drainage
(condensate backs up into tube bundle)
Capacity control malfunctions
REMEDY
Check for building power failure. Check main circuit
breaker.
Examine circuits for ground or short.
Replace fuse.
Close main circuit breaker.
Depress Stop button after safety shutdown.
Place capacity control and Cycle-Guard™ selections
in AUTO. and depress Start button.
Check chilled water and condensing water pumps,
starters and valves.
Push overload reset button. Measure pump discharge
pressure to check for solution crystallization
(see Solution Decrystallization section on page 40).
Push overload reset button.
Depress Start button after chilled water has warmed
at least 7° F (4° C). Measure chilled water temperature.
Recalibrate or replace switch if temperature is above
set point. Check capacity control setting and operation
if temperature is below switch setting (see Check
Capacity Control Operation section on page 23).
Check cooling water temperature and flow.
Check absorber pressure.
Verify capacity control is positioned at AUTO.
Check capacity control operation per Initial Control
Checkout and Adjustment section, pages 22-24.
Reset temperature control in control panel.
Check for cause of excessive load.
Check pressure drop per selection data and reset flow.
Check cooling tower operation and temperature controls.
Raise to design per selection data.
Check operation of steam traps, strainers, valves, and
condensate receivers.
Clean tubes. Determine if water treatment is necessary.
Check solution sample and add octyl alcohol if necessary
(see Adding Octyl Alcohol section on page 35).
Check absorber loss (see Absorber Loss Determination
section on page 31). If above 5° F (3° C), see Causes and
Remedies under Inadequate Purging (high absorber loss)
section on page 42.
Check calibration and operation of capacity controls (see
Check Capacity Control Operation section on page 23).
See Causes and Remedies under Solution Crystallization
on page 42.
Check the low-level switch operation and check for low
condensing water temperature.
Check refrigerant charge and thermoswitch calibration.
(See Refrigerant Charge Adjustment, Cycle-Guard Sys-
tem Operation and Thermoswitch Adjustment sections
on pages 35 and 36). Verify Cycle-Guard switch in AUTO.
Reset temperature control in control panel.
Check calibration and operation of capacity control (see
Check Capacity Control Operation section on page 23).
Check chilled water system, controls and load.
Check condensing water temperature control and
cooling tower operation.
Check steam pressure control.
Check operation of steam traps, strainer, valves,
and condensate receivers.
Check calibration and operation of capacity control (see
Check Capacity Control Operation section on page 23).
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