Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
30
HI WATER HOLD (27) 6.2.33.
When the compressor is running and Setpoint #86 “HI RETURN TEMP” is active, the Magnum will check
for high water temperature. If the control temperature is greater than Setpoint #86 for the time specified
the Magnum will place the compressor in this state. The system will be unable to load when in this state.
EXTRA 70% STEP (28) Only HVAC Software 6.2.34.
For Mitsubishi Screw compressors only. This compressor does not provide variable capacity but has two
solenoids used to regulate the compressor capacity. This will move an extra step for this type of screw
compressor.
OFF-LO OIL TMP (29) 6.2.35.
In this state the compressor is disabled. The oil temperature will be checked only if the compressor type is
a centrifugal or screw.
Centrifugal compressors - If the temperature is greater than the Saturated Suction Temperature plus
Setpoint #39 “LUBE OIL TEMP” this state will be entered.
Screw compressors – If the temperature is greater than the value in Setpoint #39 “LUBE OIL TEMP” this
state will be entered.
HI AMP UNLDING (30) 6.2.36.
For variable step compressors this state is entered when the amp draw is greater than the respective FLA
Setpoint plus half the value in Setpoint #75, “HI AMPS”. This action is to prevent a high amps safety trip
from occurring. Once the amp draw has been reduced the system state will change to HI AMP HOLD.
DEF PREPMP OUT (31) Only HVAC Software 6.2.37.
This state is only entered if the defrost type is any condition other than NONE. Hot gas will be used to
perform the defrosting. This is selected in Compressor Information button under the MAG V8 screen.
When a defrost cycle begins this state is entered and an alarm message is generated. The liquid line
solenoid will be closed and the compressor will remain in this state and continue running until the suction
pressure is less than Setpoint #61”PMP DWN OFF” or the time in this state is greater than Setpoint #62
“PMP DWN DELY”. The compressor will then move to the DEFROSTING state.
DEFROSTING (32) Only HVAC Software 6.2.38.
Refer to DEF PREPMP OUT state. In this state the hot gas solenoid is opened. The compressor will
remain in this state until both coil temperatures are greater than Setpoint #161 “DEF TERM TMP” or the
time in this state is greater than the value in Setpoint #162 “DEF TERM DEL”. The compressor will then
move to the DEF PUMP DOWN state.
DEF PUMP DOWN (33) Only HVAC Software 6.2.39.
Refer to DEFROSTING state. In this state the hot gas solenoid is closed. The compressor will remain in
this state until the suction pressure is less than Setpoint #61”PMP DWN OFF” or the time in this state is
greater than Setpoint #62 “PMP DWN DELY”. The compressor will then move to the CMP IS HOLDING
state.
HI TEMP UNLOAD (34) Only with HVAC Software 6.2.40.
This state is only used when in Heating Mode. The system will unload if Setpoint #152 “HP OVERHEAT”
is active and the leaving temperature is greater than the value in Setpoint #152 minus 15°F (8°C). The
compressor will then move to the HI TEMP HOLD state when the temperature drops below the value in
Setpoint #152 minus 30°F (16°C).
HI TEMP HOLD (35) Only with HVAC Software 6.2.41.
Refer to HI TEMP UNLOAD state. When the temperature drops below Setpoint #152 minus 45°F
(24°C) the compressor will return to a normal state.
SCROLL STEP 1 (36) Only with HVAC Software 6.2.42.
Only used with special patterns for Trane Trio and Quad compressors. These compressors provide
special staging as follows: