Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
148
# Name Description
61 PMP DWN OFF This is the suction pressure value for turning off the compressor when in the PUMP DOWN
or for opening the liquid line solenoid during the PRE-PUMP down state.
62 PMP DWN DELY Maximum time delay (in seconds) that a compressor can remain in the PUMP DOWN or
PRE-PUMP down states. The Time in sec field specifies the time the unit will remain in
unloading before shutting off the LLS & EXV and pumping down.
63 ACYC ON->ON This is the anti-cycle time delay (in seconds) from when the compressor was turned on. This
value is used in a calculation to determine how long a compressor should be in the anti-
cycle state. Refer to the Standard Control Options section 7.11, Compressor Anti-Cycle
Logic (ON to ON).
64 COMP MIN RUN This is the minimum run time (in minutes) for a compressor once it is turned on. This
minimum run time can be overridden by a safety condition, however.
65 EXV ZONE1 Temperature differential used to build the EXV Zone 1 both plus and minus.
66 EXV ZONE2 Temperature differential that is used to build the EXV Zone 2 both plus and minus.
Temperatures above this zone are considered in zone 3.
67 EXV ROC ZONE 1 The EXV control logic will compare the value of this Setpoint to the temperature rate of
change to determine the valve adjustment when the temperature is within the EXV
control zone.
‘Safety Down Time (MIN)’ field: The minimum time delay between EXV adjustments when in
the EXV control zone.
68 EXV ROC ZONE1 The EXV control logic will compare the value of this Setpoint to the temperature rate of
change to determine the valve adjustment when the temperature is within zone 1.
‘Safety Down Time (MIN)’ field: This is the minimum time delay between EXV
adjustments when in the EXV control zone 1. If this Setpoint is inactive then the ROC for
this zone is 0 and the delay is 15 seconds.
69 EXV ROC ZONE2 The EXV control logic will compare the value of this Setpoint to the temperature rate of
change to determine the valve adjustment when the temperature is within zone 2.
‘Safety Down Time (MIN)’ field: This is the minimum time delay between EXV adjustments
when in the EXV control zone 2. If this Setpoint is inactive then the ROC for this zone is 0
and the delay is 15 seconds.
70 EXV ROC ZONE3 The EXV control logic will compare the value of this Setpoint to the temperature rate of
change to determine the valve adjustment when the temperature is within zone 3.
‘Safety Down Time (MIN)’ field: This is the minimum time delay between EXV adjustments
when in the EXV control zone 3. If this Setpoint is inactive then the ROC for this zone is 0
and the delay is 15 seconds.
71 EXV TOO FAST When the superheat is with the control zone, the EXV control logic will compare the value of
this Setpoint to the temperature rate of change to determine the valve adjustment when
the temperature is within the zone and rising too fast.
‘Safety Down Time (MIN)’ field: This is the minimum time delay between EXV adjustments if
the rate of change is too fast when in EXV control zones 1 or 2. If this Setpoint is inactive
then the ROC for this zone is 0 and the delay is 15 seconds.
72 EXV CHANGING When the superheat is with the control zone, the EXV control logic will compare the value of
this Setpoint to the temperature rate of change to determine the valve adjustment when
the temperature is within the zone and rising.
73 STARTER DLAY This Setpoint controls the start of a compressor’s second relay.
If the ‘Select Value: # decimals & print char’ cell is set to ‘HUMD or %’ then logic is:
If the slide amp percentage is less than the value of this Setpoint and the first relay has been
on for 2 seconds or it has been on longer than the value in the safety time of this
Setpoint, then turn on the second relay. Else it is off.
If the ‘Select Value: # decimals & print char’ cell is set to ‘Seconds’ then the Setpoint’s value
is a time delay between the first and second relay’s starts. Used for part wind (typical
value of 1) and star delta (typical value of 5) starter.
74 OIL PUMP OFF If oil pump is always on (specified in MCS-Config), this Setpoint is not used. Otherwise this
Setpoint contains the oil pressure value when the oil pump is to be turned off.