Guardian Technologies 4390, 4456, 4389, 4760, 4759, 4758 manual Automatic Operating Parameters

SECTION 1.7		PART 1	GENERAL INFORMATION
AUTOMATIC OPERATING PARAMETERS
AUTOMATIC OPERATING SEQUENCES CHART
SEQ. CONDITION	ACTION	SENSOR, TIMER OR OTHER
1 Utility source voltage is	No action	Voltage Dropout Sensor on circuit
available.		circuit board.

2 Utility voltage dropout below	A 15-second timer on circuit
60% of rated voltage occurs.	board turns on.

Voltage Dropout Sensor and 15 second timer on circuit board.

3 Utility voltage is still below	15-second timer runs for 15
60% of rated voltage.	seconds, then stops.

Voltage Dropout Sensor and 15 second timer.

4 Utility voltage is still low after	Circuit board action energizes a	Circuit board crank and run
15 seconds.	crank relay and a run relay.	relays.
	See NOTE 1.

5Utility voltage still low and the engine has started.

Circuit board s engine warmup Engine Warmup Timer (10 seconds) timer runs for 10 seconds.

6Engine running and engine warmup timer times out. AC output voltage above 50% nominal voltage.

Circuit board action energizes a transfer relay in transfer switch and transfer to Standby occurs.

Circuit board transfer relay circuit Transfer switch transfer relay.

7 Engine running and load is	No further action	Circuit board	voltage pickup
powered by Standby power.		sensor continues to seek an
		acceptable Utility	voltage.

8Utility source voltage is restored above 80% of rated

Circuit board voltage pickup	Voltage Pickup Sensor (80%)
sensor reacts and a re-transfer	Return to Utility Timer (15 seconds)
time delay turns on.

9	Utility voltage still high after 15	Return to Utility Timer times out Return to Utility Timer
	seconds.

10 Utility voltage still high.

Circuit board action opens the transfer relay circuit to ground. Transfer relay de-energizes and retransfer to Utility occurs.

Circuit board transfer relay circuit Transfer switch transfer relay.

11Engine still running, loads are powered by Utility source.

Circuit board engine cool down timer starts running.

Circuit board Engine Cool down Timer (1 minute)

12	After 1 minute, engine cool down	Engine Cool down Timer
	timer stops and circuit board s	Circuit board Run Relay.
	run relay de-energizes. Engine
	shuts down.

13 Engine is shut down, loads are	No action.
powered by Utility source.
Return to Sequence 1.

Voltage Dropout Sensor on circuit circuit board.

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