Bosch D125B User manual

Powered loop interface
D125B
en Installation instructions

Powered loop interface Notices | en 3
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
1 Notices
These instructions cover the installation of the D125B Dual ClassB Initiating Module in a fire
system supervised by a fire alarm control panel (FACP) or a combination Burglary/Fire control
panel.
Before installing the module, become familiar with the Installation and Operation Guide for the
control panel you are using.
Install, test and maintain the module according to these instructions, NFPA codes, local codes,
and the authority having jurisdiction (AHJ). Failure to follow these instructions can result in
failure of a detector to initiate an alarm event. Bosch Security Systems, Inc. is not responsible
for improperly installed, tested or maintained devices.
!
Warning!
Follow these instructions to avoid personal injury and damage to equipment.
NFPA72 requires that you perform a complete system wide functional test following any
modifications, repair, upgrades or adjustments made to the system’s components, hardware,
wiring, programming and software/firmware.
2 Description
Use this module to connect up to 2 two‑wire powered loops (ClassB [StyleB]) to separate
on‑board points on the compatible Bosch Security Systems, Inc. control panels listed in the
table below. These loops are powered with nominal 12VDC or 24VDC for compatible smoke
detectors or glassbreak devices. You can also use any dry contact device with this module.
Control Panels Compatible modules Compatible relays See figures:
Active Products:
New G panels1B208, D308 D130, D133, D134 5.3 & 5.5
B series panels2B208, D308 D133 and D134 5.2 & 5.4
Legacy Products:*
GV4 panels3See control panel’s documentation on the Bosch website
(http://www.boschsecurity.com)
GV34 and GV25 panels
G panels6
D9412, D7412, D7212*
D9112B1, D7212B1
D8112
1 New G panels = B9512G, B8512G, B9512G-E, and B8512G-E
2 B Series = B6512**, B5512**, B5512E**, B4512**, B4512E**, B3512**, and B3512E**
3 GV4 = D9412GV4, D7412GV4, and D7212GV4**
4 GV3 = D9412GV3, D7412GV3, and D7212GV3**
5 GV2 = D9412GV2, D7412GV2, and D7212GV2**
6 G = D9412G, D7412G, and D7212G**

4en | Operation Powered loop interface
2018.06 | 4.0 | F.01U.036.340 Installation instructions Bosch Security Systems, Inc.
* Legacy products have not been investigated to comply with the latest UL864 edition.
** indicates products which are not UL Listed for commercial fire applications.
Figure2.1: D125B Powered loop interface
1 Power-limited, supervised switched
auxiliary power (detector reset)
2 Supervised connection to protective
zone or point on the control panel
3 Supervised connection to protective
zone or point on the control panel
4 Connect to only one common at the
panel
5 Connect to only one common on the
control panel
6 Power-limited, supervised negative to
B loop detectors
7 Power-limited, supervised negative to
A loop detectors
8 Power-limited, supervised positive to B
loop detectors
9 Power-limited, supervised positive to A
loop detectors
10 Earth ground
11 Mounting holes
3 Operation
The module can be powered from the control panel’s switched auxiliary power output or from
an external auxiliary power supply. Currently, the control panels can only supply 12VDC, but
external power supplies can provide either 12VDC or 24VDC.
For wiring details, see Wiring, page 6.
3.1 Power from the control panel
In this mode, the control panel switched auxiliary power output supplies regulated,
power‑limited, supervised 12VDC power to the module. The switched power output allows all
detectors connected to the module to be reset by interrupting power using the Reset Sensor
command. See Wiring for 12  VDC power supplied by the control panel, page 7.

Powered loop interface Installation | en 5
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
3.2 Power from an external auxiliary power supply
Use a separate power supply listed for fire signaling units and/or commercial or residential
burglary units. Depending on compatibility with the control panel, a D130, D133, or D134
Relay can be required to reset the smoke detectors using the Reset Sensor command. See
Wiring for 12  VDC or 24  VDC power supplied by an external power supply, page 8.
The external power supply must be UL1481 or UL864 Listed, regulated, and power‑limited.
Install the control panel and external power supply in the same room no more than 20ft (6m)
apart. The interconnecting wires between the control panel and external power supply must
be in conduit.
The power source for both the auxiliary power supply and the control panel must be from the
same dedicated AC branch circuit.
4 Installation
The module can be mounted in the D8103, D8108A, D8109, D8109G, D8109H, or D8109L
Enclosures. Only the D8108A and D8109 models are suitable for commercial fire applications.
The D8108A and D8109L enclosures require use of a D137 Mounting Bracket to install the
module. The other enclosures have several module mounting locations to which the module
can be installed using the supplied screws. Refer to the D137’s and the enclosure’s
Installation Instructions for mounting locations and instructions.

6en | Wiring Powered loop interface
2018.06 | 4.0 | F.01U.036.340 Installation instructions Bosch Security Systems, Inc.
5 Wiring
5.1 Wiring sensor loops
The D125B has two loop inputs:
Loop A Loop B
A+ (terminal 9) B+ (terminal 8)
A- (terminal 7) B- (terminal 6)
Notice!
Observe polarity when wiring detection loops. Do not cross Loop A and Loop B connections.
To supervise the loops, install an end-of-line (EOL) resistor after the last detector of each
protective loop. When installing a D125B in a new or existing system, use the 1.8kΩ EOL
resistor (P/N: F01U009011B) supplied with the module.
Notice!
To ensure system supervision, do not use looped wire under the terminals. Break the run to
provide supervision of the connections.
Figure5.1: D125B loop wiring
1 Normally‑closed contacts (NC) 4 Point input terminal
2 Normally‑open contacts (NO) 5 Common
3 Combination: Normally‑open and
normally‑closed contacts (NO/NC)
6 1.8 kΩ EOL resistor (P/
N:F01U009011B) supplied with the
module
The D125B shorts the protective loop on the control panel when the high (+) and low (-) side
of either module loop is shorted together or when a smoke detector activates. The module
opens the protective loop on the control panel during the following conditions:
– The module protective loop is opened.
– The D125B is not powered.

Powered loop interface Wiring | en 7
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
– Either the high (+) side of the loop or the low (-) side of the loop is shorted to ground.
For control panels with Ground Fault Detect, a short to ground causes a ground fault
condition when Ground Fault Detect is enabled.
When programming for fire applications, refer to the corresponding control panel operation
and installation guide.
5.2 Wiring for 12VDC power supplied by the control panel
5.2.1 Wiring a B Series panel
Figure5.2: Wiring two-wire loops powered by a B Series panel
1 Power‑limited, supervised switched
auxiliary power from Output A (NC) of
the control panel1
2 Supervised connection to Zone B
power from an on‑board point of the
panel
3 Supervised connection to Zone A
power from an on‑board point of the
panel
4 Connection with terminal 5 to only one
common on the panel
5 Connection with terminal 4 to only one
common on the panel
6 Power-limited, supervised negative to
B loop detectors (see Wiring sensor
loops, page 6)
7 Power-limited, supervised negative to
A loop detectors (see Wiring sensor
loops, page 6)
8 Power-limited, supervised positive to B
loop detectors (see Wiring sensor
loops, page 6)
9 Power-limited, supervised positive to A
loop detectors (see Wiring sensor
loops, page 6)
10 Earth ground
11 Output A jumper (under cover) set for auxiliary power applications (AUX PWR)
1 You can also use output B or C in conjunction with a D133 or D134 relay module.

8en | Wiring Powered loop interface
2018.06 | 4.0 | F.01U.036.340 Installation instructions Bosch Security Systems, Inc.
5.2.2 Wiring a G Series panel
Figure5.3: Wiring two-wire loops powered by a G Series panel
1 Power‑limited, supervised switched
auxiliary power from the control
panel’s relay C
2 Supervised connection to Zone B
power from an on‑board point of the
panel
3 Supervised connection to Zone A
power from an on‑board point of the
panel
4 Connection with terminal 4 to only one
common on the panel
5 Connection with terminal 5 to only one
common on the panel
6 Power-limited, supervised negative to
B loop detectors (see Wiring sensor
loops, page 6)
7 Power-limited, supervised negative to
A loop detectors (see Wiring sensor
loops, page 6)
8 Power-limited, supervised positive to B
loop detectors (see Wiring sensor
loops, page 6)
9 Power-limited, supervised positive to A
loop detectors (see Wiring sensor
loops, page 6)
10 Earth ground
5.3 Wiring for 12VDC or 24VDC power supplied by an external
power supply
Use either a 12VDC or 24VDC regulated, power‑limited auxiliary power supply listed under
UL864 or UL1481.
Notice!
Do not mix 12VDC and 24VDC detectors on the same module.

Powered loop interface Wiring | en 9
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
5.3.1 Wiring a B Series panel
Figure5.4: Wiring two-wire loops for power supplied by an external auxiliary power supply controlled by a relay and a B Series
panel
1 Power‑limited, supervised switched
auxiliary power from Output A (NC) of
the control panel1
2 Supervised connection to Zone B
power from an on‑board point of the
panel
3 Supervised connection to Zone A
power from an on‑board point of the
panel
4 Connection with terminal 5 to only one
common on the panel
5 Connection with terminal 4 to only one
common on the panel
6 Power-limited, supervised negative to
B loop detectors (see Wiring sensor
loops, page 6)
7 Power-limited, supervised negative to
A loop detectors (see Wiring sensor
loops, page 6)
8 Power-limited, supervised positive to B
loop detectors (see Wiring sensor
loops, page 6)
9 Power-limited, supervised positive to A
loop detectors (see Wiring sensor
loops, page 6)
10 Earth ground
11 Output A (NC) of the control panel
controls the relay
12 For 24V applications, cut this wire

10 en | Wiring Powered loop interface
2018.06 | 4.0 | F.01U.036.340 Installation instructions Bosch Security Systems, Inc.
13 Negative connection from the auxiliary
power supply to the negative terminal
of the relay and panel common
14 Positive connection from the auxiliary
power supply to the positive terminals
of the relay
15 UL Listed regulated, power limited
auxiliary power supply (12VDC or
24VDC) for fire protection systems
16 Output A jumper (under cover) set for
auxiliary power applications (AUX
PWR)
1 You can also use output B or C in conjunction with a D133 or D134 relay module
5.3.2 Wiring a G Series panel
Figure5.5: Wiring two-wire loops for power supplied by an external auxiliary power supply controlled by a relay and a G Series
panel
1 Power‑limited, supervised switched
auxiliary power from the switching
relay
2 Supervised connection to Zone B
power from an on‑board point of the
panel
3 Supervised connection to Zone A
power from an on‑board point of the
panel
4 Connection with terminal 5 to only one
common on the panel
5 Connection with terminal 4 to only one
common on the panel
6 Power-limited, supervised negative to
B loop detectors (see Wiring sensor
loops, page 6)
7 Power-limited, supervised negative to
A loop detectors (see Wiring sensor
loops, page 6)
8 Power-limited, supervised positive to B
loop detectors (see Wiring sensor
loops, page 6)

Powered loop interface Specifications | en 11
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
9 Power-limited, supervised positive to A
loop detectors (see Wiring sensor
loops, page 6)
10 Earth ground
11 Power‑limited, supervised switched
auxiliary power from the control
panel’s relay C to the switching relay
12 For 24V applications, cut this wire
13 Negative connection from the auxiliary
power supply to the negative terminal
of the relay and panel common
14 Positive connection from the auxiliary
power supply to the positive terminals
of the relay
15 UL Listed regulated, power‑limited auxiliary power supply (12VDC or 24VDC) for fire
protection systems
6 Specifications
Electrical
12VDC 24VDC
Nominal operating voltage Supplied by the control panel
or by a regulated,
power‑limited 12VDC power
supply listed under UL864 or
UL1481
Supplied by a regulated,
power-limited 24V power
supply listed under UL864 or
UL1481
Alarm Current (maximum)
– One loop only 75 mA 168 mA
– Both loops 145 mA 300 mA
Standby Current (maximum)
– One loop only 12 mA 25 mA
– Both loops 24 mA 50 mA
Electrical - two‑wire powered loop ClassB
Current 12VDC 24VDC
– Alarm > 11.8mA > 24.1mA
– Detector 3mA 7mA
– Trouble < 3.5mA < 7.5mA
Loop wire resistance 50Ω 50Ω
Environmental
Environment Indoor, dry
Operating Temperature +32°F to +122°F (0°C to +50°C)
Relative Humidity 5% to 93% at +86°F (+30°C); non-condensing

12 en | Compatible detectors and modules Powered loop interface
2018.06 | 4.0 | F.01U.036.340 Installation instructions Bosch Security Systems, Inc.
Control panel to module distance
Maximum Wire Resistance 2Ω
Maximum distance per wire size
Maximum distance Wire size
60 ft. (15m) 22 AWG (0.34mm2)
160 ft. (40m) 18 AWG (0.75mm2)
Mechanical
Dimensions (H x W x D) 5in. x 3in. x 0.8in. (12.7cm x 7.6cm x 2.0cm)
7 Compatible detectors and modules
7.1 Compatible 2‑wire detectors
Underwriters Laboratories (UL) has found the following 2‑wire detectors to be compatible
with the D125B:
Manufacturer CTN Series Base Reversing* Maximum number of
detectors per loop
12V 24V
Bosch D263 D263 N/A 8 8
D263TH 8 8
D263THC 8 8
D263THS ●8 8
D285 D285 D287,
D288,
D340
10 10
D285TH 10 10
F220-P F220 F220-B6 8 8
F220-PTH 8 8
F220-PTHC 8 8
F220-135 8 8
F220-135F 8 8
F220-190F 8 8
System Sensor 2W-B i3 N/A 8 8
2WTA-B 8 8
2WT-B 8 8
5151 100 B110LP 10 10
* D132A does not operate at 24V; use only on 12V powered loops.

Powered loop interface Compatible detectors and modules | en 13
Bosch Security Systems, Inc. Installation instructions 2018.06 | 4.0 | F.01U.036.340
7.2 Compatible modules
Underwriters Laboratories (UL) has found the following modules to be compatible with the
D125B:
CTN Manufacturer 12V 24V Reversing*
D130 Bosch ● ●
D132A reversing relay* ● ●
D133 ●**
D134 ●**
* D132A does not operate at 24V; use only on 12V powered loops.
** Relay can switch 24V, but operates at 12V.

Bosch Security Systems, Inc.
130 Perinton Parkway
Fairport, NY 14450
USA
www.boschsecurity.com
© Bosch Security Systems, Inc., 2018
Bosch Sicherheitssysteme GmbH
Robert-Bosch-Ring 5
85630 Grasbrunn
Germany