Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
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# of Compressors and # of steps:
Set up compressor:
Set up Relay Outputs:
Pattern of the three-compressor setup: 7.8.4.
Staging sequence
COMP A COMP B COMP C
Stage 1
OFF OFF ON
Stage 2
ON ON OFF
Stage 3
ON ON ON
Safeties are the same for both compressor types 7.8.5.
The standard unloading and holding logic has been incorporated with their compressor state names.
When a step is unloaded it will go to the previous step pattern. For example if the compressor is in
SCROLL STEP 3 and unloading is required the Relay Output for SCROLL STEP 2 will be used. The
state name will reflect why the compressor has unloaded.
The unloading and holding can result from high discharge and low suction pressure and high
discharge temperature.
Low and high amp drawn will be check for all compressors that are on. The standard amp safety
checks will be made and if one occurs the compressor will be off on a safety or a lock out if the same
safety reoccurs.
Note, the standard Setpoints are used for all safety checks, unloading, and holding functions.
7.9. Compressor Auto Rotation
The auto rotation option is selected by setting the value in Setpoint #103 “LEAD COMP” to zero. If this value
is nonzero, it will contain the number of the lead compressor and auto rotation will be disabled. Note this