



B520 | Bosch 12V Auxiliary Power Supply Module with SDI2 Bus Communication, 2A Output
- Regular price
- $379.00
- Sale price
- $379.00
- Regular price
-
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Product Description P/N: B520
Description
The Bosch B520 Auxiliary Power Supply Module is a 12V, 2A expansion module designed to enhance power capacity for Bosch control panels. It provides stable auxiliary power for connected devices and supervises up to two 12V batteries, ensuring reliable operation in both fire and intrusion applications. Built for industrial, commercial, and institutional systems, the B520 enables efficient power management with seamless SDI2 bus communication.
Technical Specifications
Condition | New/Never Used Surplus |
Brand | Bosch Security |
Category | Batteries & Power Supplies |
Part Number | B520 |
Subcategory | Power Supply Modules |
Output Voltage | 12 VDC |
Standby Current Output | 2 A |
Alarm Current Output | 4 A |
Battery Capacity Supported | Up to 36 Ah (two 12V 7–18 Ah batteries) |
Input Voltage | 18 VAC |
Communication Interface | SDI2 bus |
Backup Time | Up to 80 hours |
Transformer Type | Bosch TR1850 plug-in transformer |
Supervision | Independent supervision for each connected battery |
Address Configuration | Rotary switch addressing |
Material | Metal housing (panel-mounted) |
Operating Temperature | 0°C to +49°C |
Width | 6.9 in (176.2 mm) |
Height | 4.5 in (114.3 mm) |
Depth | 1.2 in (29 mm) |
Country of Origin | United States |
Weight | 1.2 lb (0.54 kg) |
Information About B520
The B520 is part of Bosch’s SDI2 accessory line, designed to deliver additional 12V power and intelligent supervision to compatible control panels. It supplies up to 2A of standby current for fire or intrusion systems and up to 4A during alarm conditions. The module independently supervises two 7–18 Ah batteries for up to 36 Ah of total capacity, with automatic reporting of any status changes to the panel. Featuring rotary address switches, SDI2 output terminals, and robust expansion support, the B520 is a dependable choice for complex security and fire installations requiring additional auxiliary power.
Key Features:
- Auxiliary Power Output: Provides up to 2A of 12V standby current or 4A of alarm current.
- Battery Supervision: Independently monitors up to two 12V 7–18 Ah batteries for a total of 36 Ah capacity.
- Extended Backup Duration: Supports up to 80 hours of standby operation for critical systems.
- SDI2 Bus Communication: Enables direct communication and supervision through Bosch control panels.
- Flexible Power Distribution: Offers SDI2 Out and AUX PWR terminals for expansion devices and sensors.
- Rotary Addressing: Simple and reliable address configuration using easy-to-read switches.
- Universal Compatibility: Works with Bosch control panels and standard TR1850 plug-in transformers.
- Compact Design: Space-efficient form factor for easy integration in enclosures.
The B520 delivers the reliability and precision required for stable auxiliary power and battery supervision in demanding fire and intrusion applications.
Description
The Bosch B520 Auxiliary Power Supply Module is a 12V, 2A expansion module designed to enhance power capacity for Bosch control panels. It provides stable auxiliary power for connected devices and supervises up to two 12V batteries, ensuring reliable operation in both fire and intrusion applications. Built for industrial, commercial, and institutional systems, the B520 enables efficient power management with seamless SDI2 bus communication.
Technical Specifications
Condition | New/Never Used Surplus |
Brand | Bosch Security |
Category | Batteries & Power Supplies |
Part Number | B520 |
Subcategory | Power Supply Modules |
Output Voltage | 12 VDC |
Standby Current Output | 2 A |
Alarm Current Output | 4 A |
Battery Capacity Supported | Up to 36 Ah (two 12V 7–18 Ah batteries) |
Input Voltage | 18 VAC |
Communication Interface | SDI2 bus |
Backup Time | Up to 80 hours |
Transformer Type | Bosch TR1850 plug-in transformer |
Supervision | Independent supervision for each connected battery |
Address Configuration | Rotary switch addressing |
Material | Metal housing (panel-mounted) |
Operating Temperature | 0°C to +49°C |
Width | 6.9 in (176.2 mm) |
Height | 4.5 in (114.3 mm) |
Depth | 1.2 in (29 mm) |
Country of Origin | United States |
Weight | 1.2 lb (0.54 kg) |
Information About B520
The B520 is part of Bosch’s SDI2 accessory line, designed to deliver additional 12V power and intelligent supervision to compatible control panels. It supplies up to 2A of standby current for fire or intrusion systems and up to 4A during alarm conditions. The module independently supervises two 7–18 Ah batteries for up to 36 Ah of total capacity, with automatic reporting of any status changes to the panel. Featuring rotary address switches, SDI2 output terminals, and robust expansion support, the B520 is a dependable choice for complex security and fire installations requiring additional auxiliary power.
Key Features:
- Auxiliary Power Output: Provides up to 2A of 12V standby current or 4A of alarm current.
- Battery Supervision: Independently monitors up to two 12V 7–18 Ah batteries for a total of 36 Ah capacity.
- Extended Backup Duration: Supports up to 80 hours of standby operation for critical systems.
- SDI2 Bus Communication: Enables direct communication and supervision through Bosch control panels.
- Flexible Power Distribution: Offers SDI2 Out and AUX PWR terminals for expansion devices and sensors.
- Rotary Addressing: Simple and reliable address configuration using easy-to-read switches.
- Universal Compatibility: Works with Bosch control panels and standard TR1850 plug-in transformers.
- Compact Design: Space-efficient form factor for easy integration in enclosures.
The B520 delivers the reliability and precision required for stable auxiliary power and battery supervision in demanding fire and intrusion applications.

