Ttp50: Unexpected Voltage On On-Board Point Wiring - Bosch D9412GV2 Troubleshooting Manual

D9412GV2/D7412GV2 | Troubleshooting Guide | 3.0
TTP50: Unexpected Voltage on On-board
Point Wiring
Initial Actions
You must understand the devices and wiring splices
contained in the circuit you are troubleshooting. If you
do not know this information, trace the wiring as
required.
Procedure
Is the on-board point connected to a module (for
example, D192 Bell Supervision Module, D125B Dual
Loop Interface Module, D113 Dual Battery Module, and
so on)?
Set your digital voltmeter (DVM) to VDC. Connect the
red DVM lead to the POINT terminal and the black
DVM lead to the COMMON terminal.
Does the DVM measure >8 VDC?
Refer to TTP16 Point Trouble on One of the
Eight On-board Points
For the remainder of this TTP, leave the DVM
connected to these same terminals.
Is there more than one piece of equipment
connected to this wire, or are there wire splices on
the wire?
At the other end of the wire, disconnect the
device.
Does the DVM still measure >8 VDC?
Properly reconnect the conductors to
the device. If the problem returns,
replace the device.
Re-run the wire, then reconnect all equipment
to the circuit.
A B
108
Troubleshooting
on page 57.
A B
IMPORTANT: The rest of this procedure uses a
half-split troubleshooting approach. By
answering the following question, you divide the
circuit in half to determine the half of the circuit
that contains the unexpected voltage. This half is
the "affected circuit".
By repeating the question, you divide the
affected circuit in half again to determine the half
of the affected circuit that contains the
unexpected voltage. That half becomes the
affected circuit.
Repeat the following question as many times as
necessary until you reduce the affected circuit
enough to identify the location of the unexpected
voltage. Refer to
During the rest of this TTP, if the TTP states
"repeat the process and question above",
return to this location in the TTP.
Disconnect the middle device or splice in the affected
circuit.
Does the DVM measure >8 VDC?
Refer to Figure 61
is between where you disconnected the device
or splice and either:
- the end of the circuit, or
- the location of the device or splice you
disconnected the last time the DVM
measured >8 VDC.
Reconnect the device or splice, then repeat
the process and question above.
Refer to Figure 61 on page 110. The problem is
between where you disconnected the device or
splice and either:
- the DVM, or
- the location of the device or splice you
disconnected the last time the DVM did not
measure >8 VDC.
Reconnect the device or splice, then repeat the
process and question above.
Set your digital voltmeter (DVM) to measure VDC. Connect
the red DVM lead to the POINT terminal. Connect the black
DVM lead to the COMMON terminal.
Does the DVM measure >8 VDC?
Refer to TTP16 Point Trouble on One of the Eight
On-board Points on page 57.
C
Bosch Security Systems, Inc. | 11/05 | F01U011024B
Figure 61 on page 110.
on page 110. The problem