
Intrusion Alarm Systems | B520 Auxiliary Power Supply Module
B520 Auxiliary Power Supply Module
www.boschsecurity.com
u Provides up to 2A of 12V standby current for Fire or
Burglar Applications (4A of Burglary alarm current)
u Supervises up to two 12v 7-18Ah batteries
independently for up to 36AH of capacity
The B520 Auxiliary Power Supply Module is a fully
supervised, addressable SDI2 bus device that provides
an integrated auxiliary power supply solution for
Bosch control panels.
System overview
The B520 Auxiliary Power Supply Module is an
auxiliary power supply expansion device that connects
to compatible control panels through the SDI2 bus.
This module is supervised and communicates back to
the control panel all status changes.
Industrial, commercial, and institutional facilities are
typical installations for the B520 module. The B520
rotary switches allow for ease of use in device
addressing. The SDI2 Out terminals provide auxiliary
power for SDI2 expansion devices such as keypads.
The AUX PWR terminals provides added auxiliary
power capabilities for additional devices such as PIR’s.
Functions
Supervision Monitoring
The module monitors and communicates status
information over the SDI2 bus for the following:
• Operation (Heartbeat)
• Battery 1 (BATT 1)
• Battery 2 (BATT 2)
• AC input power (AC)
u Provides up to 80 hours of standby time
u Uses the Bosch standard TR1850 plug-in
transformer
u Easy to read rotary switch addressing
• Battery OK
• Low Battery
• Missing Battery
Indicators
• Heartbeat [icon]: Blue LED flashing On and Off when
system is operating normally. A steady On or Off LED
indicates a system error. Triple flash indicates
communication failure.
• BATT 1 LED: Green steady On LED indicates the
battery status of BATT 1 is operating normally.
Flashing indicates low battery. Triple flash indicates
battery charger failure. Off LED indicates a missing
battery.
• BATT 2 LED: Green steady On LED indicates the
battery status of BATT 2 is operating normally.
Flashing indicates low battery. Triple flash indicates
battery charger failure. Off LED indicates a missing
battery.
• AC LED: Green steady On LED indicates the AC
power is operational. A pulsating LED (3 pulses per
sec.) occurs when a battery test is being performed.
Flashing indicates low or failed AC.
Battery Charging
Fully charged batteries, connected to the battery
terminals, sustain power to the B520 in the event that
the AC power fails.

2 | B520 Auxiliary Power Supply Module
If AC power fails (is absent, or low) on the B520, the
B520 automatically switches from primary power (AC)
to secondary power (battery). When AC power is
present, the B520 performs periodic battery tests to
ensure battery life and usability.
Certifications and approvals
Region
US UL 365 ᅳ Police Station Connected Burglar
Alarm Units and Systems
UL 609 ᅳ Local Burglar Alarm Units and
Systems
UL 636 ᅳ Holdup Alarm Units and Systems
UL 864 ᅳ Control Units and Accessories for
Fire Alarm Systems
UL 985 ᅳ Household Fire Warning System
Units
UL 1023 ᅳ Household Burglar Alarm System
Units
UL 1076 ᅳ Proprietary Burglar Alarm Units and
Systems
UL 1610 ᅳ Central Station Burglar Alarm Units
FCC Part 15 Class B
Canada CAN/ULC S303 ᅳ Local Burglar Alarm Units
and Systems
CAN/ULC S304 ᅳ Signal Receiving Centre and
Premise Alarm Control Units
ULC-ORD C1023 ᅳ Household Burglar Alarm
System Units
ULC-ORD C1076 ᅳ Propriety Burglar Alarm
Units and Systems
ICES-003 ᅳ Digital Apparatus
Region Certification
USA UL 20121010-S5579
CSFM see our website
Installation/configuration notes
Mounting Considerations
You can mount the B520 Auxiliary Power Supply
Module in a variety of enclosures for optimal
situations.
Mounting in the D8103 requires the addition on the
B12 Mounting plate.
The D8103 enclosure supports up to two 12V, 18Ah
batteries. The B10 supports either one 12V, 18Ah or
up to two 12V, 7Ah batteries.
Wiring Considerations
The B520 connects to a control panel using the SDI2
IN connections (PWR, A, B, COM). Use 12 AWG to
22 AWG (1.5 mm to 0.6 mm) wires from the power
supply to the control panel.
The B520 provides auxiliary power to expansion
modules via the SDI2 OUT (PWR, A, B, COM), or AUX
Power (AUX PWR) connections using the screw
terminal strip, or by using the interconnect wiring
connection. Use 12 AWG to 22 AWG (1.5 mm to
0.6 mm) wires from the module to the SDI2 expansion
module(s).
Parts included
Quantity Component
1 B520 Auxiliary Power Supply module
1 Hardware pack
1 Literature pack
B520 Kit, B10 Enclosure
Kit contents include:
• B520 Aux Power Supply
• TR1850 transformer
• B10 white enclosure
Order number: B520-B
B520 Kit, D8103 Enclosure
Kit contents include:
• B520 Aux Power Supply
• TR1850 transformer
• B12 mounting plate
• D8103 gray, steel enclosure
Order number: B520-C
Technical specifications
Properties
Board Dimensions 11.43 cm x 17.62 cm x 2.9 cm
Maximum Distance – Wire
Size
Compatibility GV4 Series control panels (Up to 8
(4.5 in x 6.94 in x 1.15 in)
305 m (1000 ft) - 0.65 mm (22
AWG)
305 m (1000 ft) – 2 mm (18 AWG)
Unshielded wire only
B520 Auxiliary Power Supply
Modules per control panel)
D8103 Enclosure
B10 Large Control Panel Enclosure
B12 Mounting Plate for the D8103
Enclosure
D8108A Attack Enclosure
D2203 Enclosure
BATB-40 Enclosure
AE1, AE2 Enclosures
D8004 Transformer Enclosure*
B501-10 Interconnect cables (10 per pack)

3 | B520 Auxiliary Power Supply Module
*The D8004 Transformer Enclosure is required when
the B520 and TR1850 (18 VAC, 50 VA) Transformer are
used in UL 864 Fire, or Combination Burg and Fire
applications.
Power Input
Transformer Power Supply TR1850 (18 VAC, 50 VA)
TR1850-CA (18 VAC, 50 VA) for
Canada
Power Output
Current Available (Maximum) 2.0 A SDI2 Out and AUX Power
Current Reserved for
Charging Batteries
Current Drawn from the Panel 15 mA
Voltage (rated range) 11.5 to 12.2 VDC (special
Battery Configuration Supports two*, separate 12 V sealed
(Combined) (up to 4.0 A of alarm
current for Burglar Applications)
150 mA
application)
lead acid batteries (7-18 Ah) for up to
36 amp.
*Battery 1 is required for normal
operations. Battery 2 is optional.
Enclosure Battery Considerations
D8103 Holds up to two 18 Ah, or two 7 Ah
batteries
D2203 Enclosure
Gray steel enclosure. Accepts an optional lock and
tamper switch. Measures 35.6 cm x 31.8 cm x 7.6 cm
(14 in x 12.5 in x 3 in).
Order number D2203
D8103 Enclosure
Grey steel enclosure measuring 41 cm x 41 cm x 9 cm
(16 in. x 16 in. x 3.5 in.).
Order number D8103
D8108A Attack Resistant Enclosure
Grey steel enclosure measuring 41 cm x 41 cm x 9 cm
(16 in. x 16 in. x 3.5 in.). UL Listed. Includes lock and
key set. B520, B4512, and B5512 require the B12
mounting plate.
Order number D8108A
AE1 Standard Enclosure (Gray)
Standard gray enclosure with keyed lock. Measures
35.6 cm x 31.8 cm x 7.6 cm (14 in x 12.5 in x 3 in).
Order number AE1
AE2 Standard Enclosure (Red)
Standard red enclosure with keyed lock. Measures
35.6 cm x 31.8 cm x 7.6 cm (14 in. x 12.5 in. x 3 in.).
Order number AE2
D8004 Transformer Enclosure
For applications such as fire alarm that might require a
transformer enclosure.
Order number D8004
B10 Holds up to one 18 Ah, or two 7 Ah
batteries
Environmental Considerations
Operating Temperature +32° to +120° F (0° to +49°C)
Storage Temperature -4° to 140° F (-20° to +60° C)
Relative Humidity 5% to 93% at +32° (+90°F) non-
condensing
Use Intended for indoor use.
Ordering information
B520 Auxiliary Power Supply Module
Provides auxiliary power to 12VDC devices or to SDI2
modules.
Order number B520
Accessories
B10 Medium Control Panel Enclosure
White, steel enclosure. Accepts an optional lock and
tamper switch. Measures 35.6 cm x 31.8 cm x 7.6 cm
(14 in x 12.5 in x 3 in).
Order number B10
B12 Mounting Plate for D8103 Enclosure
Required for mounting select control panels and other
devices in D8103, D8108A, D8109, or BATB Battery
Box enclosures.
Order number B12
TR1850 Transformer
For use in North America. Plug-in transformer with
input: 120 VAC, 60 Hz, 0.50 A; output 18 VAC, 50 VA
output.
Order number TR1850
D101 Lock and Key Set
Short-body lock set with one key supplied. Uses the
D102 (#1358) replacement key.
Order number D101
ICP‑EZTS Dual Tamper Switch
Combination tamper switch with a wire loop for
additional tamper outputs.
Order number ICP-EZTS
BATB-40 Battery Box\Enclosure
The BATB-40 Battery Box holds two dry or wet cell
batteries. The box can be used with fire alarm systems
or intrusion systems.
Order number BATB-40

4 | B520 Auxiliary Power Supply Module
Represented by:
Americas: Europe, Middle East, Africa: Asia-Pacific: China: America Latina:
Bosch Security Systems, Inc.
130 Perinton Parkway
Fairport, New York, 14450, USA
Phone: +1 800 289 0096
Fax: +1 585 223 9180
security.sales@us.bosch.com
www.boschsecurity.us
Bosch Security Systems B.V.
P.O. Box 80002
5617 BA Eindhoven, The Netherlands
Phone: + 31 40 2577 284
Fax: +31 40 2577 330
emea.securitysystems@bosch.com
www.boschsecurity.com
Robert Bosch (SEA) Pte Ltd, Security
Systems
11 Bishan Street 21
Singapore 573943
Phone: +65 6571 2808
Fax: +65 6571 2699
apr.securitysystems@bosch.com
www.boschsecurity.asia
Bosch (Shanghai) Security Systems Ltd.
201 Building, No. 333 Fuquan Road
North IBP
Changning District, Shanghai
200335 China
Phone +86 21 22181111
Fax: +86 21 22182398
www.boschsecurity.com.cn
Robert Bosch Ltda Security Systems Division
Via Anhanguera, Km 98
CEP 13065-900
Campinas, Sao Paulo, Brazil
Phone: +55 19 2103 2860
Fax: +55 19 2103 2862
latam.boschsecurity@bosch.com
www.boschsecurity.com
© Bosch Security Systems 2014 | Data subject to change without notice
2536892171 | en, V6, 04. Nov 2014
B520 Kit, B10 Enclosure
B520 Auxiliary Power Supply kit. Includes a TR1850
transformer and a B10 White, steel enclosure.
Order number B520-B
B520 Kit, D8103 Enclosure
B520 Auxiliary Power Supply kit. Includes a TR1850
transformer, a B12 mounting plate, and a D8103 Gray,
steel enclosure.
Order number B520-C