Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
150
# Name Description
86 HI RETURN TEMP Only active in Mitsubishi compressors. If active the Magnum will check for high entering liquid
temperature. If this temperature is greater than the value in this Setpoint, the circuit state
will be HI WATER HOLD.
87 HI DISC TMP If active, the Magnum checks for high discharge temperature for each compressor. If the
discharge temperature sensor reading is greater than this Setpoint for the specified
period of time, a safety trip will occur.
Refers to ‘Discharge Temperature’ column in the Circuit SI screen.
88 DIS TMP UNLD
(Not CENT?)
The purpose of this Setpoint is to take corrective action to prevent a high discharge
temperature safety trip. For fixed step compressors: If a compressor has more than one
step, is fully loaded, and if the discharge temperature is more than the value of Setpoint
#87 “HI DISC TMP” minus the value of this Setpoint, then one step of capacity will be
turned off. For variable step compressors: If a compressor has a discharge temperature
more than the value of Setpoint #87 “HI DISC TMP” minus the value of this Setpoint,
then the compressor will be forced to unload. The circuit state will be changed to HI DISC
HOLD, and will remain in this state for a minimum of the time in Setpoint #101 “SAFETY
HOLD DELAY”. At that time, if the discharge temperature has decreased below than the
value of Setpoint #87 “HI DISC TMP” minus the value of Setpoint #89 “HDISC T RELD”
the compressor will return to normal control.
89 DIS TMP RELD Refer to Setpoint #88 description.
90 COND FAULT For Condensers with Fault Indicators: If Setpoint is active, a condenser fault occurs, and the
Setpoint type is Alarm, then an alarm message will be generated. If the type is Lockout,
and a condenser fault occurs, then all of the compressors associated with this fault will be
locked off.
For Common VFD Fan Condensers with Bypass: Time in seconds before the bypass can be
used when a fault has occurred.
91 LOW OIL DIF If active, the Magnum checks for low differential oil pressure. If the calculated differential oil
pressure is less than this value for the specified period of time, a safety trip occurs.
Refers to ‘Oil Pressure’ column in the Circuit SI screen.
92 UNSAFE OIL If active, the Magnum checks for unsafe differential oil pressure. If the calculated differential
oil pressure is less than this value for the specified period of time, a lockout occurs.
NOTE: The time period specified should be very short (2-5 seconds). If this Setpoint trips,
the compressor will be sent straight to the Lockout state.
Refers to ‘Oil Pressure’ column in the Circuit SI screen.
93 HI OIL SEAL Only used with screw or centrifugal compressors. If the oil seal or oil cooler temperature
exceeds the value of this Setpoint for the time specified, a safety trip occurs.
Refers to ‘Oil Seal Temp’ column in Circuit SI screen.
94 HI OIL TEMP If active, the Magnum checks for high oil temperature. The sensor can be either an analog or
digital input. If the oil temperature sensor reading is ON (Digital) or exceeding the
temperature value of this Setpoint (Analog) for the specified period of time, a safety trip
occurs.
Refers to ‘Oil Temp’ column in the Circuit SI screen.
95 MOTOR FAULT If active, the Magnum checks for high motor temperature. The sensor can be either an analog
or digital input. If the motor temperature sensor reading is ON (Digital) or exceeding the
temperature value of this Setpoint (Analog) for the specified period of time, a safety trip
occurs.
Refers to ‘Motor Temp’ column in the Circuit SI screen.
96 NO CMP PROOF If active, when the compressor is called to be on by the controller, the Magnum will check for
a digital input to indicate that the compressor is indeed running. If the controller calls for a
compressor to turn on and no proof is given in the specified period of time, a safety trip
occurs.
Refers to ‘Comp Proof’ column in the Circuit Base screen
97 DIRTY FILTER Only used for screw compressors. If discharge pressure minus oil filter pressure is greater
than this value for the time specified, a safety trip occurs.