Bosch Appliances manual Fire Alarm Systems D125B Dual Class B Initiating Module, Functions

Fire Alarm Systems D125B Dual Class B Initiating Module

D125B Dual Class B Initiating Module

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The D125B has two separate NFPA Class B (Style B) powered loops. The module supervises each of the loops for opens, shorts, or ground faults. Both loops can be powered with either 12 VDC or 24 VDC to connect compatible two-wire detectors or other two- or four-wire devices such as retarded waterflow switches, manual stations, heat detectors, or glass break detectors.

The D125B is suitable for connecting fire or burglary devices in commercial, industrial, and institutional applications. Schools, offices, and health care facilities are typical commercial applications.

Functions

Loop Supervision

The D125B needs to be electrically connected to earth ground and to the control panel's common. The D125B has a supervisory output terminal for each of its loops. All terminal designations are clearly marked on the module circuit board.

To supervise the loops, install an end-of-line (EOL) resistor beyond the last detector of each protective loop. If you are replacing a D125 or D125A Module with the D125B, use the 1.5 kΩ resistor

(P/N: 15-03130-000) installed with the original system. If you are installing a D125B in a new system or are

uTwo separate powered detector loops

uSuitable for 12 VDC or 24 VDC, two‑wire or four‑wire detectors

uUp to 50 two‑wire 12 VDC glass break detectors

uReports individual loop alarm, individual loop trouble, and ground fault

uManually resets latching devices from control panel or remote central station

adding additional devices to an existing system, use the 1.8 kΩ resistor (P/N: F01U009011) 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 D125B opens the protective loop on the control panel during the following conditions:

•Either of the module protective loops are opened.

•The D125B Interface module is unpowered.

•Either the high (+) side of the loop or the low (-) side of the loop is shorted to ground.

With the D9412GV3, D7412GV3, D7212GV3, D9412GV2, D7412GV2, D7212GV2, D9412G, D7412G, and D7212G Control Panels, a short to ground causes a ground fault condition when ground fault detect is enabled.

When programming for fire applications, refer to the appropriate control panel's operation and installation guide.

Notice

Do not mix 12 VDC and 24 VDC detectors on the same D125B Module.