Guardian Technologies 4758 - Manual (Page 98)

SECTION 4.4
DIAGNOSTIC TESTS
INTRODUCTION
Perform these "Diagnostic Tests" in conjunction with
the "Troubleshooting Flow Charts" of Section 4.3.
The test procedures and methods presented in this
section are not exhaustive. We could not possibly
know of, evaluate and advise the service trade of all
conceivable ways in which testing and trouble
diagnosis might be performed. We have not
undertaken any such broad evaluation.
TEST 41 - CHECK POSITION OF AUTO-O OFF-
MANUAL SWITCH
DISCUSSION:
If the standby system is to operate automatically, the
generator
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
operation 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. An "Automatic Operating Sequences
Chart" is provided on Page 1.7-2. Use the chart as a
guide in evaluating 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 an "engine cool down timer" has
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, proceed to Test 42.
3. If engine cranks but won't start, go to Problem 10 in
Section 4.3.
4. If engine cranks and starts, but transfer to "Standby"
does NOT occur, go to Problem 5 in Section 3.3.
5. If transfer to "Standby" occurs, but retransfer back to
"Utility" does NOT occur when utility source voltage is
restored, go to Problem 6 in Section 3.3.
TEST 42 - TRY A MANUAL START
DISCUSSION:
The first step in troubleshooting for an "engine won’t
crank" condition is to determine if the problem is
peculiar to automatic operations only or if the engine
won’t crank manually either.
PROCEDURE:
1. On the generator panel, set the AUTO-OFF-MANUAL
switch to OFF.
2. Set the generator main line circuit breaker to its OFF or
open position.
3. Set the generator AUTO-OFF-MANUAL switch to
MANUAL.
a. The engine should crank cyclically through it s
"crank-rest" cycles until it starts.
b. Let the engine stabilize and warm up for a few
minutes after it starts.
RESULTS:
1. If the engine cranks manually but does NOT crank
automatically, go to Test 43.
2. If the engine does NOT crank manually, proceed to
Problem 9 in the "Troubleshooting Flow Charts".
TEST 43- TEST AUTO-O OFF-M MANUAL SWITCH
DISCUSSION:
When the AUTO-OFF-MANUAL switch is set to AUTO
position, battery voltage (12 volts DC) is delivered to the
circuit board via Wire 15A, the closed switch terminal,
Wire 15A, and Pin 10 of the circuit board connector.
This voltage is needed to operate the circuit board.
Setting the switch to its "Manual" position delivers
battery voltage to the circuit board for its operation. In
addition, when the switch is set to "Manual", 12 volts
DC is supplied to the circuit board via Pin 11 of the
board, Wire 239, the closed switch contacts, Wire 17
and Pin 9 of the circuit board connector.
Figure 1. Schematic of AUTO-OFF-MANUAL Switch
DC CONTROL PART 4
Page 4.4-1