Automatic Operation Sequence - Briggs & Stratton 1768-0 Installation Manual

Briggs& Stratton Power Products Home Generator System
Installation Manual
AUTOMATIC OPERATION
SEQUENCE
The generator's control panel houses a logic control circuit
board.This control board constantly monitors utility power
source voltage. Should that voltage drop below a preset
level, control board action will signalthe engine to crank
and stare After the engine starts, the control board signals
the transfer switch to activate and to connect load circuits
to the backup power supply.
When utility source voltage is restored above a preset
voltage level,the control board signalsthe transfer switch
to transfer loads back to the power supply.After retransfer,
the engine is signaled to shut down.
The actual system operation is not adjustable and is
sequenced by sensors and timers on the control board, as
follows:
UtUityVoltage Dropout Sensor
• This sensor monitors utility source voltage.
• If utility source voltage drops below about 60 percent of
the nominal supply voltage, the sensor energizes a
6-second timer.The timer is used to 'sense' brown-outs.
• Once the timer has expired, the engine will crank and
start_
Engine Warm-up Time Delay
This mechanism lets the engine warm up for about
I 5 seconds before the load is transferred to the Home
Generator System.
Backup Voltage Sensor
This sensor monitors generator AC output voltage.When
the voltage has reached 50 percent of the nominal rated
voltage, transfer to the backup generator can occur.
UtilityVoltage Pickup Sensor
This sensor monitors utility power supply voltage.When
that voltage is restored above 70 percent of the nominal
source voltage, a retransfer time delay starts timing.
Retransfer Time Delay
• This timer runs for about 6 seconds.
• At the end of a 6-second delay, circuit board action de-
energizes the generator relay in the transfer switch.
• Retransfer to utility power source then occurs.
Engine Cool-down Timer
• When the load is transferred back to the utility power
source, the engine cool-down timer starts timing.
• The timer will run for about one minute, then the
generator will stop.
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