Main Circuit Breaker; Frame Ground Connection; Battery Disconnect Switch; Shutting Down The Unit - Generac Power Systems MGG155 Operating Manual

Operation

MAIN CIRCUIT BREAKER

When the main circuit breaker is OFF (O), power is interrupted between the bus connections and the generator.
Once connections have been made to the bus bars and the generator has been started and allowed to reach normal
operating temperature, the breaker may be switched ON (I).
The main circuit breaker will be tripped, disconnecting power to the bus connections, if any of the following conditions
occur while the unit is running:
• Overload of the generator circuits to the bus connections. At 105% load, there will be an audible warning.
At 110% load, the breaker opens and power will be disconnected.
• The customer connection box door is opened.
• The emergency stop switch is activated.
Verify any problems that cause the main circuit breaker to trip are corrected before returning the switch to ON (I).

Frame Ground Connection

Follow all NEC, state and local regulations pertaining to frame ground connections.
Determine ground stud location and connect the ground wire to the "earth ground" terminal. This ground is the local
reference ground to ground the unit frame only.

Battery Disconnect Switch

The unit is equipped with a battery disconnect switch which allows the operator to disconnect power from the batteries
by turning the switch to OFF.

SHUTTING DOWN THE UNIT

1. Verify power to the load can be interrupted. There may be other procedures that must be done before shutting
a unit down, depending on the application.
Open the Main Circuit Breaker (MCB) by pressing the right I/O button on the controller.
2.
Allow the unit to cool down (running at no-load) for approximately five minutes to prevent damage to critical
3.
engine components.
Press STOP on the controller.
4.
Turn the battery disconnect switch to OFF.
5.
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Figure 14 - Frame Ground Connection
MGG155/210 Operating Manual
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