Bosch D9412GV2 - Ground Fault Symptoms; TTP42: Ground Fault on Control Panel

D9412GV2/D7412GV2 | Troubleshooting Guide | 3.0 Troubleshooting
.
Bosch Security Systems, Inc. | 11/05 | F01U011024B 95
3.5 Ground Fault Symptoms
Table 50: Ground Fault Symptoms
Symptom Corrective Action
Ground fault on control panel
Refer to TTP42 Ground Fault on Control Panel on page 95.
Control panel sends “Trouble Point 256” message to
central station.
Refer to
TTP43 Control Panel Sends “Trouble Point 256” Message
to Central Station on page 96.
Control panel sends “BTO/BTR” message to central
station.
Refer to TTP44 Control Panel Sends “BTO/BTR” Message to
Central Station on page 96.
Cannot enable the ground fault detect function.
TTP45 Cannot Enable Ground Fault Detect
Refer to
on page 96.
TTP42: Ground Fault on Control Panel
8. One at a time, disconnect a conductor from the
affected terminal until you identify the conductor
that causes the voltage reading to change on the
DVM. This is the affected conductor.
Procedure
1. Close the GROUND FAULT DETECT ENABLE
pin on the control panel (
). Figure 55
9. To troubleshoot the affected conductor, refer to
2. Set your digital voltmeter (DVM) to measure
VDC.
on page 106. TTP49 Wire Shorted to Ground
Figure 55: Ground Fault Detect Enable Pin
3. Connect the red DVM lead to control panel
Terminal 9, and the black DVM lead to
Terminal 10. Record the voltage shown on the
DVM.
GROUND FAULT DETECT
Enabled
Disabled
S4
PHONE
LED
RED
ON when
communicating
OFF when idle
PHONE LINE SEIZED
TIP
RING
TELCO CORD
MODEL D161
3
1
2
4. Remove the terminal block with Terminals 11 to
16 from the control panel, and record the voltage
shown on the DVM. If the voltage changed, this is
the affected terminal block. Install the terminal
block and proceed to Step 5.
5. If the voltage did not change, repeat Step 3 for the
terminal block with Terminals 17 to 22 and the
terminal block with Terminals 23 to 32, until you
identify the terminal block that causes the voltage
change at the DVM. Install the terminal block.
6. Refer to
Table 51 on page 96. Determine the
terminals on the affected terminal block that
caused the recorded voltage reading at Terminals 9
and 10 in Step 3.
7. One terminal at a time, disconnect all conductors
from a terminal identified in
Table 51 until you
identify which terminal causes the voltage reading
to change on the DVM. This is the affected
terminal. Reconnect all conductors.
1 - Pin in closed position
2 - Pin in open position
3 - Pin location on control panel board