Overload Ground Fault (Ogf); Evaporator Heaters; Ogf Checkout Procedure; Figure 8−34 Light Bar Connections - Carrier VECTOR 6500 Operation & Service Manual

b. Check for 12 VDC to the +12V from the switch. If re-
quired, correct wiring.
c. Check for ground at the PRM OV terminal. If required,
correct wiring.
d. Check for a 12 VDC signal from the PRM to micropro-
cessor terminal 5MP04. If required, correct wiring
from PRM to the microprocessor.
e. If all wiring and voltage readings are correct, replace
PRM.
H
A
G
B
C
F
E D
LIGHT BAR
SIDE
Figure 8−34 Light Bar Connections
8.9.3 Light Bar
The light bar may be tested using a 12 VDC source. To
test the light bar:
a. Connect the ground (-) from the power source to pin B
on the light bar side of the connector.
b. The green LEDs will illuminate when the 12 VDC side
(+) of the power source is connected to pin G.
c. With the connection as in the preceding steps (+ on
pin G, and - on pin B), the amber LEDs will illuminate
when the ground (-) from the power source is also
connected to pin G.

8.9.4 Overload Ground Fault (OGF)

a. Operation
The OGF is designed to detect current overload and
fault to ground in the AC voltage circuits. The function of
the OGF is to shut down the power supply (generator or
standby) when current is over 40 amp for 2 seconds, or
leakage to ground is more than 150mA.
Power, from SP52, energizes the OGF at terminal +12
V. The module is grounded by the microprocessor at the
OV terminal through microprocessor terminal 1MP15.
This power also flows through the OGF normally closed
contacts and the S+ terminal to the GENCONR relay,
PSCONR relay and microprocessor terminal 2MP26. If
an overload or excessive leakage to ground condition
exists, the OGF contacts open to de-energize the relays
and stop the flow of power to microprocessor terminal
2MP26. Loss of power at 2MP26 activates the A100 -
62-11389
H
A
G
B
F
D E
C
CONTROL BOX
SIDE
8−34
"OVERLOAD/GROUND FAULT" alarm and illuminates
the OGF mounted fault LED.
b. OGF Checkout Procedure
1. Check the FAULT LED on the module. If the LED is
illuminated the module has activated and 12 VDC
power supply is correct. Perform a megohm test
(refer to Section 8.9.1) to determine if a fault to
ground exists. This test will also help determine if an
excessive current condition exists due to leakage to
ground. Repair wiring or components as required.
2. If a problem with the module is suspected, check for
12VDC power to the module at the +12V terminal
and ground at the OV terminal. Correct wiring as re-
quired. Reset module by placing the Main Power
switch in the OFF position and then back in the de-
sired position. Check for 12 VDC at the S+ terminal.
If LED is off and the module normally closed connec-
tion is open, replace module.
3. If module is OK, check for 12 VDC at SP61 and wir-
ing through to microprocessor terminals 2MP26,
4MP7 & 5MP7 as required.
4. If a problem with the current sensors is suspected,
check sensor output. Current sensor inputs to the
module are rated at 16.7mV per Amp. For every Amp
that is read at the wires coming from the GENCON
T1, T2 and T3 terminals with an amp meter, there
should be a corresponding voltage reading on the
blue, brown & orange wires to the black wire. For ex-
ample: 20Amps = 0.33VAC.
GROUND
FAULT
L1
L2
L3
OV
+12V
Figure 8−35 Overload Ground Fault Connections

8.9.5 Evaporator Heaters

NOTE
A good preliminary test of the heaters is to run a
Pretrip and check for heater alarms
a. Ensure the unit will not start automatically by dis-
abling any two way communication and placing the
Main Power switch in the OFF position. Disconnect
the high voltage source and lockout/tagout the re-
ceptacle.
b. Remove the lower back panel or coil cover as applic-
able.
S+ +12V OV
BLUE
BROWN
TO CURRENT
ORANGE
SENSORS
BLACK
S+