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A Firefly safety switch

The Firefly Safety 'Knife'Switches

The new FireFly, from the designer and developer of the industry standard Piranha is the trade name for our new range of 400 amp DC safety/monitor and control switches. These units are designed to sit in-between the power source and the diver, providing a safe method of isolating current and voltage to the diver/operator as well as monitor and control operations.  

We offer two model types.

The utility case (standard) units are fitted with amp and volt meters to provide accurate measurements of welding parameters (amps/volts), as well as providing open circuit voltage (OCV) data; this being a very important safety feature* as well as circuit efficiency data, to show if any circuit resistance issues will present any welding difficulties.  The units are also fitted with an indicator lamp to show when the circuit is live (Hot).  

Although initially designed for welding/cutting underwater, the devices are equally well suited for situations where close control of thermal operations in hazardous areas is required.

* Please refer to IMCA document D045 – Code of practice for safe use of electricity underwater.


Firefly welding switch

Firefly welding switch


Technical Specifications

All switches are fitted with a 100%, 400 amp duty cycle push/pull switch, which meets CE directives, Underwriters Laboratories and Canadian Standards Association approvals. All units are fitted with DINSE style panel plugs and sockets as standard and are supplied with a full, return to base, 12 months warranty against defective parts or faults.

1: Utility case model: - is a portable, brief-case style unit housed in a Storm/Peli case, having the following external dimensions; L: 361mm, W: 290mm, D: 165mm and weighs approximately 5.5Kg

2: Junior: - is the same as the standard utility case model, but comes without any amp/volt meters, but is fitted with an indicator lamp to show when the circuit is Hot. The Junior is therefore more suited to cutting operations. 

Colour options are black or olive.

For full technical specifications please see our

Firefly Safety Welding Switch Brochure.

The Nautilus Firefly Safety Welding Switch Brochure


Close-up of a Firefly welding safety switch Close-up of the connectors on a Firefly welding safety switch Close-up of the voltmeter on a Firefly welding safety switch

For inquiries and to purchase any of our products contact:

David J. Keats
+44 (0) 7974 931591