D9412G/D7412G/D7212G Installation & Troubleshooting Quick Reference Guide
D9412G/D7412G/D7212G
Page 21
© 2004 Bosch Security Systems, Inc.
43700F
Troubleshooting
5.
Once the voltage has been determined, remove the wire(s) from the terminals listed and verify the voltage on
Terminals 9 and 10 is approximately 6.5 to 6.8 VDC. If the voltage does not measure within this range after
removing the suspected wire, continue to check the remaining wires connected to the terminal group.
To verify that the wire removed has an earth ground short, disconnect the DVM and switch the DVM to read
Ohms. Attach the red lead of the DVM to the end of the wire that was removed (making sure that the
connection is on the conductor of the wire and not the jacket). Attach the black lead of the DVM to Terminal 10
of the control panel. If there is an earth ground short, the reading may be from 0 to 95 k
Ω
.
Continue troubleshooting the field wiring to eliminate the ground. Begin the process by starting in the middle
of the wire run and checking which side of the wire run has the earth ground short. A known earth ground is
needed for the test.
Once the earth ground fault is isolated, remove the ground, repair the wire, or replace the wire.
6.
If the voltage being read represents a ground fault on terminals 25, 26, or 28 the ground fault condition may
physically be on either the Zonex Bus, Popit Bus, or an input point on an OctoPopit or Popit. To isolate the
ground fault in this scenario, follow these steps:
a.
Disconnect the positive and negative leads to the battery or batteries.
b.
Connect the jumper wire from Terminal 10 to Terminal 9 for approximately 5 sec.
c.
Points that have a ground fault on the input loop will change to an open state while terminals 9 and 10 are
shorted.
DO NOT
keep the jumper wire on terminals 9 and 10 for longer than 10 sec. This procedure is
only to be used in tracking down ground fault conditions.
3.17
Panel Buzzer
Beginning with revision 6.30 and higher on D9412G/D7412G Control Panels and revision 6.50 and higher on the D7212G
Control Panel, the control panel’s on-board buzzer will pulse 1 sec. on, 1 sec. off, if a supervised command center no longer
responds to polls from the panel. The buzzer will be silenced when the supervised command center begins to respond to
polls again or by pressing a Command 4 from an operational command center.
