Test 22 - Check 23 And 194 Circuit - Generac Power Systems 7 kW NG Repair Manual

Section 3.4
Diagnostic Tests
TEST 22 – CHECK 23 AND 194 CIRCUIT
Discussion
An OPEN circuit in the switch control wiring will prevent a
transfer from occurring. Terminal "A" of the transfer relay (TR1)
connects to Wire 194 and terminal "B" connects to Wire 23.
Wire 194 provides 12 VDC to terminal "A", and the Controller
holds Wire 23 open from ground. With Wire 23 open from
ground TR1 is de-energized.
Reference: De-energized TR1 relay voltage checks:
• Wire 194 to Ground = 12VDC
• Wire 194 to Wire 23 = 0 VDC
• Wire 23 to Ground =12 VDC
Procedure/Results
1. Disconnect and isolate Wire 23 from the transfer
switch terminal strip coming from the Generator. Set
the Generators AUTO-OFF-MANUAL to AUTO position;
simulate a Utility failure.
2. Once the Generator is running, connect a jumper wire
from ground to Wire 23 located at the terminal strip.
Listen and visually watch for the energizing of the TR1
relay and for the transfer to Standby.
a. If the TR1 relay visually and audibly energized and the
CONTACTOR transferred to the "Standby" position, stop
testing, proceed to Test 25 "Check Wire 23".
b. If the transfer relay did not energize, continue to Step 3.
c. If the TR1 relay visually and audibly energized and the
CONTACTOR did not transfer to the "Standby" position,
proceed to Test 23 "Test Transfer Relay."
3. Set the Generators AUTO-OFF-MANUAL switch to the OFF
position.
4. Set Volt-Ohm-Milliammeter (VOM) to measure DC voltage.
5. Connect the negative (-) test lead to ground in the transfer
switch. Connect the positive (+) test lead to Wire 194 at
the terminal strip located in the transfer switch.
a. If voltage is present, proceed to Step 6.
b. If voltage is not present, proceed to Step 17.
6. Connect the positive (+) test lead to Wire 23 at the
terminal strip located in the transfer switch. Connect the
negative (-) test lead to a ground in the transfer switch.
a. If voltage is present, proceed to Step 9.
b. If voltage is not present, proceed to Step 7.
7. Set VOM to measure resistance.
8. Remove Wire 23 and Wire 194 going to the TR1 relay
from the terminal strip. Connect the meter test leads
across Wire 23 and Wire 194 (going to the relay).
a. The VOM should indicate TR1 coil resistance of
approximately 115 ohms.
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b. If coil resistance is not measured, remove Wire 23 and
Wire 194 from the TR1 relay. Measure across terminal
A and terminal B of the TR1 relay.
c. If coil resistance is measured, repair or replace Wire
23 or Wire 194 between the terminal strip and the TR1
relay.
d. If coil resistance is not measured, replace TR1 relay
and retest.
Note: Re-connect wires before proceeding to Step 9.
9. Connect the negative (-) test lead to the ground lug in the
Generator control panel. Connect the positive (+) test lead
to Wire 23 in the Generator at the customer connection
terminal strip.
a. If voltage is present, proceed to Step 10.
b. If voltage is not present, repair wiring between transfer
switch and Generator control panel.
10. Simulate a power failure (Open Utility Service Breaker)
with the AUTO-OFF-MANUAL switch in the AUTO position.
Approximately 10 seconds after starting, Navigate to the
digital output screen.
11. Press "ESC" three times.
12. Press the right arrow key until "Debug" is flashing.
13. Press "Enter."
14. Press the right arrow key until "Outputs" is flashing.
15. Press "Enter".
16. Digital Output 8 is the Wire 23 output from the controller.
Refer to Figure 77.
17. If Output 8 shows a "1" then the control board is
grounding Wire 23.
a. If Output 8 did not change replace the controller.
b. If Output 8 did change, proceed to next step.
18. Locate and disconnect the J4 connector from the
controller.
19. Set the VOM to measure resistance.
20. Connect one meter test lead to J4 Pin 20 (Wire 23) on the
connector. Connect the other meter test lead to J4 Pin 19
(Wire 194). VOM should indicate approximately 115 ohms.
a. If the VOM indicated approximately 115 ohms, repair or
replace the J4 Pin 20 connection.
b. If the VOM indicated INFINITY, repair or replace Wire 23
between J4 connector and the Generator terminal strip.
c. If resistance is not within specification, proceed to Test
23 – "Test Transfer Relay."
21. Set VOM to measure DC voltage.
22 Connect the negative (-) test lead to the ground lug in the
Generator control panel. Connect the positive (+) test
lead to Wire 194 at the terminal strip in the Generator
control panel.
TRANSFER SWITCH