Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
154
# Name Description
136 VI PULSE
Used with an adjustable VI, volume ratio. This is the pulse time expressed in tenths of a
second to adjust the VI.
137 VI DEADBAND
Used with an adjustable VI, volume ratio. If the VI reading is greater than the VI wanted ratio
plus the value of this Setpoint, then the increase RO is off and the decrease RO is
pulsed. If the VI reading is less than the VI wanted ratio minus the value of this Setpoint,
then the increase RO is pulsed and the decrease RO is off.
138 VI DELAY This is the time delay between VI wanted ratio calculations.
139 OIL FLOAT If active, the Magnum checks for an oil float digital input. It must be ON for the period of time
specified in the Setpoint before this Setpoint will trip.
140 NOT IN USED: 208 Compressors with a low SI Off sensor will be disabled when the sensor is below this Setpoint.
141 NOT IN USED: 209 Compressors with a high SI Off sensor will be disabled when the sensor is above this
Setpoint.
142 SERVICE MODE If non-zero, then a compressor being disabled by the pump down switch will be continue to
run until its suction pressure is zero. The compressor will be turned on to perform the
pump down the number of times indicated in this Setpoint. This is in preparation for
service to be performed on the compressor.
143 UNLOADED % Used if a slide percentage sensor is present. When this sensor is reading less than the value
of this Setpoint, then the slide is considered unloaded. Also used for a centrifugal vane
closed. If the vane% sensor is reading less than the value of this Setpoint, then the vane
is considered closed.
Optional: If Setpoint is set up as a target, the value of this Setpoint equals the % at which the
slide is considered closed. If the Time(SEC) field is set > 0 then slide control will be used
instead of AMPS. High & low zone are used to develop the control zone based upon the
capacity wanted %. Make Setpoint #35 “AMP DB HI” and Setpoint #36 “AMP DB LO”
non-active.
144 OIL HEATER ON The oil heater will be turned on if the oil temperature is less than the value of this Setpoint. It
will be turned off if the oil temperature is greater than the value of this Setpoint plus 5.0°
Fahrenheit.
‘Time (sec)’ field: If zero, then the calculated oil temp will be the saturated suction
temperature plus the value of the Setpoint. Else it will be the value of this Setpoint.
145 OIL COOLER ON The oil cooler will be turned on if the oil seal temperature is greater than the value of this
Setpoint. It will be turned off if the oil seal temperature is less than the value of this
Setpoint minus 5.0° Fahrenheit.
146 PROC TARG Process pump target. The control value can be either temperature or pressure.
147 PROC ZONE Process pump control zone. This value is added to Setpoint #146 “PROC TARG” to calculate
the high value and subtracted to calculate the low value of the control zone. The process
pump’s VFD will be modulated to maintain inside this zone. The adjustment to the pump
speed is calculated by subtracting the controlling SI from the value of Setpoint #146. This
range has a minimum of 1% ADJ and a maximum of 15%.
148 PROC DELY Process pump delay in seconds before next change. If calculated adjustment (Target minus
controlling SI) is greater than the zone x2, or if the slope is greater than the ROC x2,
decrement twice as fast.
149 PROC MAX ROC Process pump rate of change limit. If the ROC exceeds this value, no change is required. The
ROC window equals the value of Setpoint 148 to a maximum of 60 seconds.
150 PROC MIN SPD% Minimum process pump speed if using the Modulating (AO) option.
Number of Relay Outputs that will be staged if using the Staging (RO) option.
151 UNLOADED OFF If active, the system is fully unloaded, and the control temperature is greater than this value,
then the capacity state will be set to holding.
‘Time (sec)’ field: If non-zero, then the value of this Setpoint is used as a differential and not a
set temperature. The value of this Setpoint is subtracted from Setpoint #1.