Johnson Controls York MaxE YK Series, Manual

Page: 121 / 139

JOHNSON CONTROLS
FORM 160.75-O1 (309)
22
results possiBle cause remedY
1 . s Y m p t o m : a B n o r m a l l Y h i g h d i s c h a r g e p r e s s u r e
Temperature difference between conden-
Air in condenser.
sing temperature and water off condenser
higher than normal.
High discharge pressure.
Condenser tubes dirty or Clean condenser tubes. Check water
scaled conditioning.
High condenser water
Reduce condenser water inlet
temperature.
temperature. (Check cooling tower
and water circulation.)
Temperature difference between conden- Insufficient condensing Increase the quantity of water through
ser water on and water off higher than water flow. the condenser to proper value.
normal, with normal evaporator pressure.
2 . s Y m p t o m : a B n o r m a l l Y l o W s u c t i o n p r e s s u r e
Temperature difference between leaving Insufficient charge of Check for leaks and charge
chilled water and refrigerant in evaporator refrigerant. refrigerant into system.
greater than normal with high discharge
Variable orifice problem. Remove obstruction
.
temperature.
Temperature difference between leaving
Evaporator tubes dirty or Clean evaporator tubes.
chilled water and refrigerant in the evaporator
restricted.
greater than normal with normal discharge
temperature.
Temperature of chilled water too low with
Insufficient load for Check prerotation vane motor opera-
with low motor amperes.
system capacity. tion and setting of low water temper-
ature cutout.
3 . s Y m p t o m : h i g h e V a p o r a t o r p r e s s u r e
High chilled water temperature.
Prerotation vanes fail to Check the prerotation vane motor
open. positioning circuit.
System overload.
Be sure the vanes are wide open
(without overloading the motor) until
the load decreases.
4. sYmptom: no oil pressure When sYstem start Button pushed
Low oil pressure displayed on control
Oil pump running in wrong Check rotation of oil pump
center; compressor will not start.
direction. (Electrical Connections).
Oil pump not running.
Troubleshoot electrical problem
with oil pump VSD.
operational maintenance
taBle 1 –
OPERATION ANALYSIS CHART
section 5 – trouBleshooting