Calibrate Utility Voltage Sensing Circuit Board; Section 4 - Maintenance; Operate Transfer Switch; Clean And Inspect Transfer Switch - Generac Power Systems GTS "W" Owner's Manual

3.24 CALIBRATE UTILITY VOLTAGE
SENSING CIRCUIT BOARD
The utility sensing interface reduces utility source volt-
age ar a fixed ratio. Thus, if utility voltage varies from
the nominal, sensing voltage to the circuit board also
varies. For that reason, you may need to calibrate the
circuit board to match the system (Figure 3.17).
The installed transfer switch must be rated at a
!
voltage and phase that is compatible with the
utility and standby power supplies. DO NOT
attempt to calibrate any utility voltage sensor
board on any non-compatible unit trying to
make the unit compatible.
Once the circuit board has been properly calibrated, the
voltage that was present during calibration establishes
100 percent utility voltage for "pickup" and "dropout"
settings. Utility source voltage must be available to the
transfer switch during calibration.
You must also use this procedure to calibrate a
replacement circuit board. Follow these instructions:
1. In the transfer
Maintenance Disconnect Switch to "Manual".
2. On the Utility Voltage Sensor circuit board, locate
test points "TP3" and "TP4" and install a jumper
lead.
3. Locate the small potentiometer "R10". Turn the
potentiometer fully counterclockwise.
4. Now, turn the "R10" potentiometer SLOWLY clock-
wise until the "Utility On" light emitting diode (LED)
just turns ON.
5. Remove the jumper wire from "TP3" and "TP4".
6. Reset the Maintenance Disconnect switch to AUTO-
MATIC.
RESULTS:
• If the "Utility On" LED does NOT go on as described
above, replace the utility voltage sensor board.
Calibrate the new board and perform a "Normal Test"
of the system.
• If the "Utility On" LED goes ON, discontinue the test.
NOTE:
switch enclosure,
Section 4 — Maintenance
Generac GTS "W" Type Transfer Switch
Figure 3.17 — Utility Voltage Sensing Circuit
4.1

OPERATE TRANSFER SWITCH

Operate the transfer switch at least once each month.
This can be done by performing a NORMAL TEST of the
system. Because the System Test switch only simulates
failure of the UTILITY power source, service will be
interrupted only during the actual transfer of the load.
set the
4.2 CLEAN AND INSPECT TRANSFER
SWITCH
Protect the transfer switch against construction grit,
metal chips, excessive moisture and other harmful dirt
at all times. At least once each year turn OFF all power
supplies to the switch, then brush and vacuum away
dust and dirt that has accumulated inside the enclo-
sure. After cleaning, inspect the transfer switch careful-
ly. Look for evidence of arcing, burning, hot spots, char-
ring and other damage. If any of these are found, have
the switch assembly checked by an authorized service
technician.
4.3

LUBRICATION

Operating parts inside the transfer mechanism have
been properly lubricated at the time of assembly. Under
normal conditions no additional lubrication should be
required. The service technician should lubricate all
recommended points whenever major transfer mecha-
nism components are replaced.
Board
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