Safety transformers

Our 12 V and 24 V safety transformers

A safety transformer steps the mains down to a safety extra-low voltage (SELV), to supply equipment and circuits that can be touched or that operate in damp conditions. Our standard models range from 63 VA to 20 kVA, in IP00, IP23 or IP54, with a price shown for every power rating:

• 230 V / 24 V safety transformer: gate motors, solenoid valves, control circuits and lighting at 24 V AC.
• 230 V / 12 V safety transformer: halogen lamps, swimming pool lights and equipment running on 12 V AC.
• 400 V / 24 V transformer: 24 V control circuits on a 400 V installation, with the primary connected between two phases.
• 230 V or 400 V primary with two secondaries: 2 × 12 V or 2 × 24 V.

In a more compact format, our 12 V and 24 V toroidal transformers, also wound and tested in Gailhan, range from 50 VA to 2 kVA.

What is a safety transformer?

A safety transformer, also called a safety isolating or safety isolation transformer, is a transformer whose primary and secondary are two separate windings, and whose output is a safety extra-low voltage (SELV): no more than 50 V AC. Its requirements are set by EN 61558-2-6. The separation between the mains and the output, combined with the low voltage, means it can supply circuits that are accessible to touch.

The difference from an isolation transformer: an isolation transformer, which comes under EN 61558-2-4, also separates the circuits, but its output can be 230 V or more. An autotransformer, on the other hand, does not separate the input from the output, so it cannot provide SELV.

Where is safety extra-low voltage (SELV) needed?

• Damp locations: lighting and equipment installed where water increases the electrical risk.
• Funfairs and fairground rides: SELV is required there for lighting and for circuits accessible to the public.
• Swimming pools: 12 V AC pool lights, with the transformer installed outside zones 0, 1 and 2 of the pool; the installation must comply with IEC 60364-7-702 (NF C 15-100 in France). See our garden and pool transformers.
• Gates and automation: motors, electric strikes, intercoms and solenoid valves at 24 V AC. See our transformers for gates.
• Low-voltage lighting: 12 V or 24 V halogen spotlights and lamps. See our lighting transformers.
• Control circuits: 24 V relay and contactor coils. See our control transformers.

How to choose the right model

Voltage

It is marked on the rating plate of the equipment: “24 V AC”, “24 VAC” or “24 V ~” calls for a 24 V transformer. A transformer delivers alternating current: for equipment marked “DC” (LED strips, electronics), you need a DC power supply. On the primary side, the supply is 230 V between phase and neutral, or 400 V between two phases for the 400 V and dual-voltage models.

Power rating

Add up the power of the equipment to be supplied, multiply by 1.25 and choose the next rating up: a 200 W gate motor needs 250 VA.

Cable and protection

At 12 or 24 V the current is high: over a long run, the cable cross-section must be calculated to limit the voltage drop. On the primary side, fit an aM fuse or a type D circuit breaker; on the secondary side, protection rated for the output current. The ratings for each size are given on the product pages.

IP rating

IP00 for mounting in a cabinet or enclosure, IP23 with a ventilated cover in a dry room, IP54 in a moulded housing or sealed enclosure for sheltered outdoor use. See our page on IP and IK protection ratings.

Standards: EN 61558-2-6 for safety isolating transformers

Our 12 V and 24 V single-phase transformers comply with the transformer safety standards in force: EN 61558-2-4, which covers isolating transformers, and EN 61558-2-6, which covers safety isolating transformers. Our extra-low-voltage toroids also come under EN 61558-2-6. Thermal protection can be added on request. Medical locations come under another part of the standard, EN 61558-2-15.

Wound and tested in Gailhan, with a 2-year warranty

ABL Transfo has been manufacturing transformers since 1993 in its workshop in Gailhan, in the Gard, southern France. Our single-phase safety transformers are wound, wired and 100 % tested there before they leave, and carry a 2-year warranty. Standard models are dispatched from France within 24 to 48 hours. For installers, integrators and suppliers, a trade account shows prices excluding VAT, with an immediate 5 % discount.

Need another voltage or a quote?

For another extra-low voltage or several secondaries, configure a custom single-phase transformer online, from 63 VA to 20 kVA, with an instant price. For a batch or a special requirement, request a quote: we reply within 48 hours.

See also our custom transformers.