Troubleshooting Guide - York YCAS0130 Installation, Operation & Maintenance Manual

Troubleshooting
PROBLEM
No display on panel -
unit will not start
NO RUN PERM displayed
(No run permissive)
SYS # HIGH OIL TEMP
Chiller FAULT: LOW
AMBIENT TEMP displayed
Chiller FAULT: HIGH
AMBIENT TEMP displayed
Recirculated air is affecting the sensor.
Chiller FAULT: LOW
WATER TEMP displayed
Chiller FAULT: VAC
UNDERVOLTAGE
displayed.
200

TROUBLESHOOTING GUIDE

POSSIBLE CAUSE
Main supply to control system OFF.
Emergency stop device off.
CB3 tripped.
No supply to - T2.
No 24VAC supply to power board.
No +12V output from powerboard.
No liquid fl ow through the evaporator.
Flow switch or cycling contacts are
Flow switch contacts are not made.
not made.
Poor airfl ow through the condenser
coils.
Measured temperature incorrect.
Ambient air temperature is lower
than the programmed operating
limit.
Measured temperature is incorrect.
Ambient air temperature is higher
than the programmed operating limit.
Resid. heat is not being dissipated.
Measured temperature is incorrect.
Leaving liquid drops below the
programmed low limit faster than the
unit can unload.
Unit is not unloading.
Measured temperature is incorrect.
Poor main supply voltage.
ACTION POSSIBLE CAUSE
Switch on main supply if safe to do so.
Check if control panel emergency stop switch
and any remote emergency stop devices are in
the OFF position. Turn to ON position (1) if safe
to do so.
Check CB3.
Check 115VAC to L & 2.
Check wiring from - T2 to powerboard and fuse.
Replace powerboard or isolate excessive load on
the board.
Ensure that liquid pumps are running. Valves are
correctly set and fl ow is established.
Check that the fl ow switch is functional and is
installed according to the manufacturer's instructions.
Check cycling contacts.
Check for airfl ow restrictions caused by blockages on
intake faces of air coils.
Check oil temp sensor and wiring.
Use the 'ambient temp.' key to display the
temperature and confi rm that the displayed value is
approximately correct. The warning message should
clear when the ambient air temperature rises above
the programmed operating limit.
Check the programmed settings are correct for the
options fi tted to the unit.
Check ambient sensor and wiring.
Use the 'ambient temp.' key to display the
temperature and confi rm that the displayed value is
approximately correct. The warning message should
clear when the ambient air temperature falls below
the programmed operating limit.
Check that the programmed settings are correct for
the options fi tted to the unit.
Check fans are operating correctly and the rotation is
correct. Check for airfl ow recirculation.
Check ambient sensor and wiring.
Check for restrictions in the liquid fl ow line.
Check that the liquid fl ow is stable.
Check the voltage to the unloader valve solenoid.
Check that the compressor unloads correctly.
Check water temp sensor and wiring.
Check main supply is stable and within allowable
limits.
Check for voltage dip on compressor start.
FORM 201.19-NM1 (204)
ACTION
YORK INTERNATIONAL