Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
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within the time in the ‘Lockout Delay Hrs’ cell since the first trip, the circuit will be set to CMP LOCKED OUT state,
which requires a manual reset to restart the compressor. If the lockout delay time is set to zero, the Magnum will
generate a lockout condition the first time that the safety occurs.
Sensor Inputs Used With Magnum Setpoint Safeties: 8.3.1.
 Suction Pressure(Analog or Digital)
 Discharge Pressure (Analog or Digital)
 Oil Pressure (Analog or Digital)
 Oil Differential Pressure (Calculated value)
 Oil Temperature (Analog or Digital)
 Discharge Temperature (Analog or Digital)
 Motor Temperature (Analog or Digital)
 Motor Amps (Analog or Digital)
 Motor Fault (Analog or Digital)
 Liquid Temperature (Analog Only)
 Compress Proof (Digital Only)
 Flow Switch (Digital Only)
Setpoint safeties 8.3.2.
For a safety trip to occur, both the Sensor Input and the associated Setpoint must be active. If a safety
trips, the alarm name will consist of the Setpoint name plus additional identification such as point number,
compressor number, or 30 second history leading up to the trip if applicable.
Note: Most safeties are checked only if the compressor is running, however if the safety is always
checked it will be noted.
The following is a list of safeties that are incorporated in the standard chiller algorithm control. These
safeties are checked every second. For a system with multiple circuits, each one is tested individually. If
a safety trip occurs, only that respective compressor will be affected, the others will continue to function
normally.
Freeze Protection (SAFETY IS ALWAYS CHECKED)
If the leaving temperature drops below the Setpoint value then the entire system will Lock Out and a
FREEZE alarm will be generated. There is also an option to have one freeze protect for each individual
circuit. Refer to section 13 Setpoint #111.
No Flow Protection
If a flow switch is used, then the entire system will be Locked Out if Setpoint #105 is active. If the Setpoint
is inactive, the Magnum will determine if there is a second pump, if so it will be started. Else, the system
will shut down and automatically restart when the flow switch is on, indicating flow has returned. There is
also an option to have a flow switch for each individual circuit. Refer to section 13 Setpoint #105.
Phase Loss Protection
Phase loss, as indicated by the phase loss monitor, will result in the entire system being Locked Off and a
phase loss alarm will be generated. If Setpoint #166 is inactive the Magnum will wait for 2 seconds before
the Lock Out occurs. The alarm will be PHASE LOSS and no restart will be attempted. If Setpoint #166 is
active, the name of the Setpoint will be in the message. Refer to section 13 Setpoint #166.
Low Differential Oil Pressure
This safety is designed to meet the compressor manufacturer requirements on oil pressure. For the first 5
seconds following a compressor start (60 seconds if Hitachi screw compressor) this safety is NOT
checked. For the next 30 seconds, if the oil differential pressure drops below ½ of the value of the
Setpoint or the digital input turns ON for the time specified in the ‘Time (sec)’ field of that Setpoint, then the
circuit will be Locked Out and a LOW OIL alarm generated. After this time period, if the oil differential
pressure drops below the value of the Setpoint and it remains there for the time specified in the ‘Time
(sec)’ field, then the compressor will be Locked Out and a low oil alarm generated. This safety is checked
for when the compressor is on and not in a Pump Down state. Refer to section 13 Setpoint #91.