Autronica BHH-31A/EX Optical Smoke Detector – Ex Intrinsically Safe (116-BHH-31A/EX)

Product Information

Manufacturer	Autronica Fire and Security (Norway)
Model (label)	Smoke Detector, Type BHH-31A/EX
Autronica part number	116-BHH-31A/EX
Related model (customer reference)	BHH-31A (non-Ex version)
Detector type	Optical, analogue addressable smoke detector head with addressing unit
ID-NR (label)	A163810 25
Approvals on label	FM Approved, CE, EN 54-7, 1134-CPD-016, Insp. Inst. AFS-05533
Ex label (blue)	BH-31A/…, Nemko 03ATEX… (partly hidden), Pi = 0.65 W, N.7483
Inside	Addressing PCB with DIP switch
Quantity in photo	3 detectors
Condition	Refurbished
Supplier	SM MARINE SERVICE™, Chattogram, Bangladesh

Product Introduction

The Autronica BHH-31A/EX is an analogue addressable optical smoke detector head for hazardous areas, used in Autronica marine and offshore fire detection systems. It detects smoke from fires with mainly visible particles and is certified intrinsically safe for zone 1 and zone 2. SM MARINE SERVICE™ stocks many Autronica smoke and heat detectors, including BHH-31A, BHH-31A/EX and BHH-26, and supplies them worldwide. Visit https://www.smmarineservice.com/ for more fire detection and marine automation spare parts.

What Is This Equipment?

The BH-31A/EX detector consists of the BHH-31A/EX detector head mounted on a BWA-40A/1 socket. The head contains an optical smoke chamber and an addressing unit with DIP switches, so each detector has its own address on the fire alarm loop. Because it is intrinsically safe (EEx ib IIC T5), it must be connected through the Autronica BZ-32 zener barrier. Autronica lists the BHH-31A/EX as obsolete, which makes tested spare units important for ships still running these systems.

Main Features

• Analogue addressable optical smoke detection
• Intrinsically safe: EEx ib IIC T5, ATEX Category II 2 G
• For hazardous areas zone 1 and zone 2
• Address set by DIP switch on the internal PCB
• Not affected by radio interference from mobile phones (manufacturer data)
• Bayonet head for quick replacement in the BWA-40A/1 socket
• Approved to EN 54-7 and EN 54-9, FM approved

Autronica BHH-31A/EX optical smoke detectors – SM MARINE SERVICE™

Main Technical Specifications

From the Autronica BH-31A/EX datasheet.

Ex classification	EEx ib IIC T5, II 2 G
Ex certificate	Nemko 03ATEX 219X
Entity parameters	Ui = 17.5 V, Pi = 0.65 W, Ci = 30 nF, Li = 0
Supply voltage	14 VDC ± 2 V
Current	0.3 mA standby, 8 mA in alarm
Working temperature	−20 °C to +70 °C
Protection	IP 44D
Humidity	Max. 90% RH, non-condensing
Weight	580 g complete
Standards	EN 54-7, EN 54-9, EN 50014, EN 50020

Inside the Unit: PCBs, Modules & Part Numbers

BHH-31A/EX Detector Head – 116-BHH-31A/EX

Optical smoke sensing head with addressing unit (shown in the photos).

Addressing PCB with DIP Switch

Green PCB inside the head for the loop address and analogue signal. Separate PCB part number: Not verified.

BWA-40A/1 Socket

Base for the BHH-31A/EX head with bayonet fastening.

BWP-40B Mounting Box

Optional mounting box for the socket.

BZ-32 Zener Barrier

Required barrier between the safe-area fire panel loop and the Ex detectors.

Main Components & Related Units

• BH-31A/EX standard version and BH-31A/S/EX extra-high sensitivity version
• BHH-31A (non-Ex) and BHH-31A/S heads
• BHH-26 optical smoke head (for BWA-100 socket)
• AutroSafe detectors: BHH-200, BHH-220, BHH-300, BHH-320, BHH-500, BHH-500/EX, BHH-520 and heat detectors BDH-200, BDH-300, BDH-500
• AutroGuard Retro – Autronica’s 1:1 replacement range for AutroSafe detectors

Marine & Industrial Applications

• Fire detection in hazardous areas on tankers, gas carriers and offshore units
• Pump rooms, paint stores and other Ex zones on ships
• Autronica analogue addressable fire alarm systems

Inside the BHH-31A/EX: addressing PCB with DIP switch and type label

Common Problems & Troubleshooting

• Detector not responding on the loop: check DIP switch address, barrier BZ-32 and wiring.
• Frequent false alarms: the smoke chamber may be dirty; clean or replace the head.
• Fault on panel: check head seating in the socket and loop voltage.

Safety note: This is Ex equipment. Only replace with an identical certified type, keep the zener barrier in the circuit, and follow hot-work and Ex procedures in hazardous areas. Disable the detector zone on the panel before testing.

Common Alarms

Alarm and fault messages are shown on the Autronica fire panel; refer to the panel documentation.

Maintenance Tips

• Test detectors regularly with approved test smoke.
• Clean detector heads in dusty areas.
• Record each detector’s address before removal.

Spare Parts & Replacement Availability

For a quotation, please send the detector label photo (type, e.g. BHH-31A/EX or BHH-31A), quantity and vessel name. SM MARINE SERVICE™ also stocks other Autronica detector models such as BHH-26. We ship worldwide from Bangladesh and China. Specific condition and availability are subject to confirmation.

Why This Equipment Is Still Used

Many ships still run Autronica systems with BHH-31A series detectors. As the model is obsolete, identical spare heads are the easiest way to keep the fire alarm system approved without changing sockets or wiring.

FAQ

What is the Autronica BHH-31A/EX?
An intrinsically safe analogue addressable optical smoke detector head.

What is its part number?
116-BHH-31A/EX.

What is the difference between BHH-31A and BHH-31A/EX?
The /EX version is certified for hazardous areas (EEx ib IIC T5) and needs a BZ-32 zener barrier.

Which socket is used?
BWA-40A/1.

What is BHH-31A/S/EX?
The extra-high sensitivity Ex version.

What supply voltage is needed?
14 VDC ± 2 V from the loop.

How is the address set?
With the DIP switch on the internal PCB.

Is the BHH-31A/EX still produced?
No, Autronica lists it as obsolete.

Do you have other Autronica detectors?
Yes, including BHH-26; please ask for others.

Do you ship worldwide?
Yes, from Bangladesh and China.

Short Product Description

The Autronica BHH-31A/EX (part no. 116-BHH-31A/EX) is an intrinsically safe analogue addressable optical smoke detector head for Autronica fire detection systems. Certified EEx ib IIC T5 (Nemko 03ATEX 219X) for zone 1 and zone 2, it runs on 14 VDC loop power through a BZ-32 zener barrier and mounts in a BWA-40A/1 socket. The address is set by DIP switch on the internal PCB. Approved to EN 54-7 and FM, it is used in pump rooms and hazardous areas on tankers, gas carriers and offshore units. SM MARINE SERVICE™ supplies refurbished BHH-31A/EX, BHH-31A and other Autronica detectors worldwide, subject to confirmation of condition and availability.

---

SM MARINE SERVICE™ – Marine Automation & Navigation Equipment Supplier
Available Equipment Conditions: New • Used • Refurbished • Reconditioned (Specific product condition and availability are subject to confirmation.)
Stock Locations: Bangladesh • China
Services: Worldwide Shipping • Technical Support • Spare Parts Supply • Marine Equipment Sourcing
Samir Market, DT Road, Pahartali, beside CDA Market, Chattogram, Bangladesh
Mobile / WhatsApp / Viber: +88 01818 929292
Email: info@smmarineservice.com
Website: https://www.smmarineservice.com/

Contact us today with your detector label photo for a fast quotation on Autronica smoke and heat detectors.

-

+

Buy Now