Ground Start; Relay Installation; Phone Monitor Select Jumper; Figure 10: Phone Monitor Select - Bosch D7212G Operation And Installation Manual

6.11

Ground Start

Some telephone systems require a momentary ground input to initiate dial tone. To interface with a ground start system,
insert a D136 Plug-in Relay into the GND START socket and set the Phone Monitor Select jumper to the GND START
position.
Ground start is not for use in NFPA applications. You cannot use ground start telephone systems for NFPA Central
Station Protective Signaling or Remote Station applications.
WARNING
Note: Terminal 10 must be connected to an earth ground in order for ground start phone systems to operate properly on the
D7212G.
6. 1 1. 1

Relay Installation

Power down the system before inserting the D136 relay into the GND START socket. The relay socket is in the lower left
corner as shown in Figure 7 on page 30. The plug-in relay is shorter than the socket it plugs into. It can be installed in either
the left or right end of the socket.
Don't rely on relay labeling: Don't rely on the labelling to install D136 relays. Check for the side with three pins. The three
pins go on the top side on the socket.
Incorrect insertion does not damage the relay or the panel, however the related circuits do not function properly. A ground
start relay must not be inserted if the ground start jumper is in the loop start position (see Figure 10).
6. 1 1.2

Phone Monitor Select Jumper

The Phone Monitor Select jumper is above the TELCO connector point at the lower left corner of the panel. Set it in the
ground start position. See Figure 10.
© 2003 Bosch Security Systems
Loop Start
Position
Ground Start
Position

Figure 10: Phone Monitor Select

D7212G Operation and Installation Guide
Page 33
Telephone Connections
GROUND FAULT DETECT
Enabled
Disabled
PHONE MONITOR SELE
LOOP
GND
GROUND START
Requires
Relay Model
D136 in Ground
Start Socket
D7212G
4998138544C