Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
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If running compressors at 100% is not desired, then the “Last Stage to 100% (Override Setpoint)” cell in
the Compressor Information panel of the MAG V8 screen should be set to ‘No’. Then the maximum
capacity allowed will be the value in Setpoint #30. If ‘Yes’, then all compressors will load to the value in
Setpoint #30 until all compressors are on, then they will load to 100% together.
7.29. Chilled Water Pump Control
The current Magnum software will support a chilled water pump plus a backup with rotation logic. These
must be set up in MCS-Config. Setpoint #105 and Setpoint #106 are used with this control logic.
 If Setpoint #105 “PUMP FAILURE” is active, flow is lost for the period of time contained in the
‘Time (sec)’ field, and only one pump is present, then the system will move to a LOCKED OUT
state. If the system has two pumps and flow is lost, then the backup pump will start and the lead
pump will be locked out. A Lockout Reset will be required to restart the system or to reactive a
locked out pump.
 If Setpoint #105 is inactive and the flow is lost, the system will move to the OFF- NO EVAP
FLOW state. When flow is returned the system will automatically restart, no reset is required.
Setpoint #106 “LEAD PUMP” indicates whether the rotation option is active or which pump is the lead
pump.
 If Setpoint #106 is zero, then rotation of the pumps will occur whenever the lead pump is turned
off. If no rotation has occurred during the current day, a forced rotation at midnight will occur. This
forces at least one rotation per day.
 If Setpoint #106 is non-zero, then rotation of the pumps is inactive and the value will specify the
lead pump. This Setpoint can be changed in a live unit and the appropriate action will be taken.
7.30. Process Pump (Heat Exchanger) Control
The Magnum software can support either variable or fixed stages of heat exchangers with up to two
process pumps with rotation and control based upon pressure or temperature. This option is specified in
the Evaporator Information panel in the MAG V8 screen.
The pump information must be set up in the Evaporator Information Panel under the MAG V8 screen. The
following information is required for each pump if used:
Pump Relay Output
Pump VFD Analog Output (if used)
VFD fault (if used)
Pressure Sensor Input (if used)
Pressure sensor output (if used)
Process temperature (if temperature control)
The following Setpoints are required:
#146 “PROC TARGET”
#147 “PROC ZONE”
#148 “PROC DELAY”
#149 “PROC MAX ROC”
#150 “Proc MinSpd%”
#197 “LEAD ProcPmp”
#198 “PROC PUMP FLT”
See Section 13 for Setpoint descriptions.
The process pump is on whenever the chilled water pump is on.