Ground Fault Symptoms; Ttp42: Ground Fault On Control Panel - Bosch D9412GV2 Troubleshooting Manual

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3.5

Ground Fault Symptoms

Table 50: Ground Fault Symptoms
Symptom
Ground fault on control panel
Control panel sends "Trouble Point 256" message to
central station.
Control panel sends "BTO/BTR" message to central
station.
Cannot enable the ground fault detect function.

TTP42: Ground Fault on Control Panel

Procedure
1. Close the GROUND FAULT DETECT ENABLE
pin on the control panel (
2. Set your digital voltmeter (DVM) to measure
VDC.
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.
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
identify which terminal causes the voltage reading
to change on the DVM. This is the affected
terminal. Reconnect all conductors.
Bosch Security Systems, Inc. | 11/05 | F01U011024B
D9412GV2/D7412GV2 | Troubleshooting Guide | 3.0 Troubleshooting
Corrective Action
Refer to
Refer to
to Central Station
Refer to
Central Station
Refer to
Figure 55 ).
Table 51 until you
TTP42 Ground Fault on Control Panel
TTP43 Control Panel Sends "Trouble Point 256" Message
on page 96.
TTP44 Control Panel Sends "BTO/BTR" Message to
on page 96.
TTP45 Cannot Enable Ground Fault Detect
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.
9. To troubleshoot the affected conductor, refer to
TTP49 Wire Shorted to Ground
Figure 55: Ground Fault Detect Enable Pin
1
2
GROUND FAULT DETECT
3
1 - Pin in closed position
2 - Pin in open position
3 - Pin location on control panel board
on page 95.
on page 96.
on page 106.
S4
Enabled
Disabled
ON when
PHONE
communicating
RED
LED
OFF when idle
PHONE LINE SEIZED
TIP RING
TELCO CORD
MODEL D161
95