Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
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System (unit) information is shown in the top section:
 Capacity Control State - State of chiller
 Time - Time spent in current state. If the state is UNIT IN POWER UP time will count down to zero.
 Wanted / Actual - Number of capacity steps Wanted On versus Actual On.
 Step Delay – Value that is counted down. The sensitivity and difference between the control sensor and
control zone will determine the speed of the countdown. When this value reaches zero, the controller will
determine if a change in the system capacity is required.
 Wanted % - Wanted slide percentage.
 Rate Of Change – Rate of Change of control sensor.
 Control On - The control sensor value. The name and the reading will be displayed, with color to indicate its
relationship to the target Setpoint.
 Mode - The mode can be either COOLING or HEATING.
Compressor information (all active compressors will be displayed):
 State - Compressor number and state. The default Compressor number can be changed in MCS-Config with
a 3 character entry in the “Comp Name/ID” column of the Circuit Base screen.
 Time - Time spent in current state. If the state is CMP ANTICYCLE time will count down to zero.
 Oil Diff - Oil differential pressure. It is calculated as follows:
Semi hermetic screws ........................................................... Oil PSI - Suction PSI
OR .......................................................................................... Discharge PSI - Suction PSI
Open drive horizontal and Carlyle screw compressor ........ Oil PSI - Discharge PSI
Reciprocating compressors .................................................. Oil PSI - Suction PSI
All Others ............................................................................... Oil PSI - Discharge PSI
 FLA % - Full Load Amps based on the compressor’s respective Setpoint. For screw compressors this
calculation is based current operating conditions.
 Steps - Indicates number of steps associated with this compressor that are turned on.
 Lead? - YES will be displayed for the lead compressor.
Compressor Superheat information:
 Suction Temp - Compressor number and Suction Temperature, if available.
 Saturated Suction - Calculated Suction Saturated Temperature (R22, R134a, R407c, and R410a are
supported).
 Suction Superheat - Calculated Suction Superheat, only available if both the Suction Temperature and the
Suction Pressure are used. Suction Superheat = Suction Temperature - Suction Saturated Temperature.
 Disc Temp - Discharge Temperature, if available.
 Saturated Discharge - Calculated Discharge Saturated Temperature (R22, R134a, R407c, and R410a are
supported).
 Disc Superheat - Discharge Superheat is available only if both the Discharge Temperature and the
Discharge Pressure are used. Discharge Superheat = Discharge Temperature - Discharge Saturated
Temperature.
 Ref Type – Refrigerant type used.