FireClass 517.050.041 — 4B universal detector base, 4 inch, for Tyco/FireClass MX addressable detectors.
The 4B family is named for its 4-inch (109 mm) diameter, and this is the plain universal member of it. Unlike the 4B-C continuity base (517.050.042) and the 4B-I isolator base (517.050.043), it has no short-circuit isolator and no spring contact to bridge the loop when a detector is pulled. Fit it where the detector itself carries the isolation.
- 20 to 40 V DC MX loop
- 25 mm high, 109 mm diameter, 64 g, flame-retardant ABS
- -25°C to +70°C; 10 to 95% RH non-condensing; indoor only
- Park position, detachable locking device, LED aperture plug
- Two 1.5 sq mm or one 2.5 sq mm conductor per terminal; on the 4B, terminal L2 is not used
The manufacturer literature we could find is European (Tyco MZX) and Australian/New Zealand, written to AS 1670.1 and NZS 4512. We found no UL or ULC listing for this catalogue number — confirm acceptance with your AHJ before specifying it on a US NFPA 72 job.
