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SECTION 4.4
DIAGNOSTIC TESTS
GENERAL
Perform the tests in this section in conjunction with
the "Troubleshooting Flow Charts" of Section 4.3.
Test numbers in this section correspond with the
numbered tests in Section 4.3.
TEST 1 - CHECK AUTO-OFF-MANUAL SWITCH
POSITION
DISCUSSION:
If the standby system is to operate automatically, the
generator's AUTO-OFF-MANUAL switch must be set
to AUTO. That is, the generator will not crank and
start on occurrence of a "Utility" power outage unless
that switch is at AUTO. In addition, the generator will
not exercise every seven (7) days as programmed
unless the switch is at AUTO.
PROCEDURE:
With the AUTO-OFF-MANUAL switch set to AUTO,
test automatic operation. Testing of automatic opera-
tion can be accomplished by turning OFF the "Utility"
power supply to the transfer switch. When the "Utility"
power is turned OFF, the standby generator should
crank and start. Following startup, transfer to the
"Standby" source should occur. Refer to Section 1.8
in this manual for an "Automatic Operating
Sequences Chart". Use the chart as a guide in evalu-
ating automatic operation.
Following generator startup and transfer to the
"Standby" source, turn ON the "Utility" power supply
to the transfer switch. Retransfer back to the "Utility"
source should occur. After a "minimum run timer" and
an "engine cooldown timer" have timed out, generator
shutdown should occur.
RESULTS:
1. If normal automatic operation is obtained, discontinue
tests.
2. If engine does not crank when "Utility" power is turned off,
go on to Test 2 of Problem 1 in Section4.3.
3. If engine cranks but won't start, go to Problem 3 in
Section 4.3.
4. If engine cranks and starts, but transfer to "Standby" does
not occur, go to Problem 4 in Section 4.3.
5. If transfer to "Standby" occurs, but retransfer back to
"Utility" does not occur when that source voltage is
restored, go to Problem 5 in Section 4.3.
TEST 2 - TRY TO START ENGINE MANUALLY
DISCUSSION:
With the AUTO-OFF-MANUAL switch set to AUTO, a
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PART 4
"Utility" power source outage should result in engine
cranking and startup. If that power source fails and
the engine does not crank, the first step in trou-
bleshooting should be to see if a manual startup can
be accomplished.
PROCEDURE:
1. On the generator panel, set the AUTO-OFF-MANUAL
switch to OFF.
2. Set the generator's main line circuit breaker to its OFF or
"Open" position.
3. Set the AUTO-OFF-MANUAL switch to MANUAL. The
engine should crank and start.
RESULTS:
1. If the engine will not start manually either, go to Problem
2 in the "Troubleshooting Flow Charts".
2. If the engine cranks and starts manually, but will not
crank in automatic mode, go to Test 3.
TEST 3 - TEST AUTO-OFF-MANUAL SWITCH
DISCUSSION:
Power for control board operation is taken from the
Wire 15 circuit (fused 12 volts DC) and delivered to
the circuit board through AUTO-OFF-MANUAL switch
contacts when the switch is set to AUTO or MANUAL.
A defective switch can produce the same results as
setting the switch to OFF (engine will not crank).
Switch at "Manual"
183
15A
239
15C
178
15A
Figure 1. Schematic of AUTO-OFF-MANUAL Switch
PROCEDURE:
Disconnect all wires from switch terminals, to prevent
interaction. Use a volt-ohm-milliammeter (VOM) to
test for continuity across switch terminals as follows:
DC CONTROL
LIQUID COOLED
ENGINE UNITS
Switch at "Auto"
183
15A
239
15C
178
15A
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