Guardian Technologies 4758 User Manual
Page 25
SECTION 1.7
AUTOMATIC OPERATING PARAMETERS
PART 1
GENERAL INFORMATION
Page 1.7-2
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
Voltage Dropout Sensor and 15
60% of rated voltage occurs.
board turns on.
second timer on circuit board.
3
Utility voltage is still below
15-second timer runs for 15
Voltage Dropout Sensor and 15
60% of rated voltage.
seconds, then stops.
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.
5
Utility voltage still low and
Circuit board s engine warmup
Engine Warmup Timer (10 seconds)
the engine has started.
timer runs for 10 seconds.
6
Engine running and engine
Circuit board action energizes a
Circuit board transfer relay circuit
warmup timer times out.
transfer relay in transfer switch
Transfer switch transfer relay.
AC output voltage above
and transfer to Standby occurs.
50% nominal voltage.
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.
8
Utility source voltage is
Circuit board voltage pickup
Voltage Pickup Sensor (80%)
restored above 80% of rated
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
Circuit board transfer relay circuit
transfer relay circuit to ground.
Transfer switch transfer relay.
Transfer relay de-energizes and
retransfer to Utility occurs.
11
Engine still running, loads are
Circuit board engine cool down
Circuit board Engine Cool down
powered by Utility source.
timer starts running.
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.
Voltage Dropout Sensor on circuit
powered by Utility source.
circuit board.
Return to Sequence 1.