Guardian 4389 Repair Manual page 116

SECTION 4.4
DIAGNOSTIC TESTS
224A
66
1
4
7
224B
A
14
Figure 33. Battery Charge Relay Test Points
TEST 67 - CHECK BATTERY CHARGE RELAY
(BCR)
DISCUSSION:
The battery charge relay is used to switch the AC
source delivered to the battery charger. When the
BCR is de-energized, the Normally Closed (NC) con-
tacts deliver AC power from the transformer. When
the BCR is energized by Wire 14, the Normally Open
(NO) contacts close and battery charge winding AC
source is delivered to the battery charger.
PROCEDURE:
1. See Figure 33. Disconnect all wires from the battery
charge relay, to prevent interaction.
2. Set a VOM to its "R x 1" scale and zero the meter.
3. Follow the chart below and test each set of contacts.
Connect the VOM test leads to the relay terminals indi-
cated in the chart provided below.
4. To energize or de-energize the relay. Connect a jumper
wire to a positive (+)12VDC source and to relay Terminal
"A". Connect a jumper wire to the negative (-) 12VDC
source and to relay Terminal "B". The relay will ENER-
GIZE. Disconnect the positive jumper from Terminal "A"
of the relay and the relay will DE-ENERGIZE.
CONNECT VOM
TEST LEADS ACROSS
Terminals 6 and 9
Terminals 3 and 9
Terminals 4 and 7
Terminals 1 and 7
Page 114
225A
2 3
77
5 6
8 9
225B
B
0
DESIRED METER READING
ENERGIZED DE-ENERGIZED
Continuity Infinity
Infinity Continuity
Continuity Infinity
Infinity Continuity
PART 4
RESULTS:
1. Replace the battery charge relay if it fails any of the
steps in this chart.
2. If the BCR tests good, but still does not function during
generator operation, check Wire 14 and Wire 0 connect-
ed to the BCR.
a. Set a VOM to measure DC volts. Disconnect
Wire 14 from BCR Terminal "A". Connect the
positive (+) test lead to Wire 14. Connect the
negative (-) test lead to a clean frame ground.
Set the AUTO-OFF-MANUAL switch to MANU-
AL. Battery voltage should be measured. If bat-
tery voltage is not measured, repair or replace
Wire 14 between the BCR and the 4-tab termi-
nal block.
b. If voltage was measured in "a", set the VOM to
measure resistance. Disconnect Wire 0 from
BCR Terminal "B". Connect one test lead to
Wire 0. Connect the other test lead to a clean
frame ground. CONTINUITY should be mea-
sured. If CONTINUITY was not measured,
repair or replace Wire 0 between the BCR and
the ground terminal.
TEST 68 - CHECK BATTERY CHARGE
WINDING HARNESS
DISCUSSION:
This test will check the continuity of Wire 66 and Wire
77 between Connector C2 and the battery charge relay.
PROCEDURE:
1. Disconnect Connector C2 from the side of the control
panel. The C2 connector is the closest to the back
panel (see Figure 9, Section 6).
2. Disconnect Wire 66 from Terminal 6, and Wire 77 from
Terminal 4 of the BCR.
3. Set a VOM to measure resistance.
12
11
10
9
8
7
Figure 34. C2 Connector Pin Locations (Male Side)
DC CONTROL
1
2
3
4
5
6