Magnum MMG75CAN6, Operating Manual, Page: 19 / 52

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• “Password” screen: The operator may press the “  ” or “  ” buttons on the “DIAGNOSTICS” keypad to
move the cursor (>) up or down a list of text.
• History screen: The operator may press the “  ” or “  ” buttons on the “DIAGNOSTICS” keypad to move
the cursor (>) up or down a list of recent alarm or shutdown codes. Pressing the “ENTER” button at a particular
selection will allow the operator to scroll to the right in the LCD window to view the generator operating
parameters at the time of the alarm or shutdown. The history of alarms or codes is saved in the digital
controller. The most recent alarm or code is the first to be listed, with the time/date of the alarm or code at
the bottom of the screen. The controller stores up to 117 codes. When full, the controller will automatically
remove the oldest file. These codes will not be lost when the “CONTROL ON/OFF” toggle switch is powered off.
Note: To view the display screens longer, push the “PAGE SELECT” button on the “DIAGNOSTICS” keypad until
you reach the “Ready” screen. Then press the “

” or “

” buttons to navigate to the screens you want. The screens
will display for approximately 45 seconds.
WET STACKING
The generator is powered by a diesel engine. Diesel engines are susceptible to wet stacking if lightly loaded. Wet
stacking occurs when an engine is run at less than 30% of its full load capacity, causing unburned fuel to accumulate
in the exhaust system. Wet stacking can be detected by continuous black exhaust when the unit is under a constant
load. It can also cause fouling of injectors and buildup on engine valves. Diesel engines operate properly when applied
loads are between 30% and 100% capacity. Appropriate generator sizing is determined by the anticipated load. If the
unit is in a wet stack condition, load the unit heavily for five hours or until the exhaust is clear.
FINE VOLTAGE ADJUSTMENT
Upon startup of the generator, the “Running” screen of the Magnum Digital
Controller (MDC) will display “V Detect” and will countdown from 45 seconds to
zero. This is a safety feature of the controller to protect the generator from over
or under voltage upon startup.
“V Detect” is a 45 second time delay and countdown process before the MDC
records the generator nominal output voltage. This nominal generator voltage
is then compared to the current set point voltage of the voltage selector switch.
If the nominal voltage recorded by the controller is greater than or lower than
the current set point voltage of the voltage selector switch setting by 10% or
more, the controller will shut the generator down automatically. The display will
read: “Wrn Gen L1 <V”, “Wrn Gen L2 <V”, “Wrn Gen L3 <V” or “Sd Gen L1 <V”,
“Sd Gen L2 <V”, “Sd Gen L3 <V”. This means the controller warned (“Wrn”) or
shut down (“Sd”) the unit due to an output voltage irregularity.
The output voltage of the generator may be adjusted after the generator is running by using the fine voltage adjustment
screw. The adjusting screw is located directly below the “CONTROL ON/OFF” toggle switch on the control panel.
CONTROL
ON
CONTROL
OFF
Voltage
Adjustment
Screw