Toroidal transformer 230 V / 24 V
24 V AC · 50 to 2,000 VA · mounting dish supplied
5.0 · 27 reviews200 VA8.33 A at 24 V · Ø 110 × 43 mm
- Mounting disha single centre bolt
- Colour-coded leads230 V · 24 V
- Labelcolour code
- —
- —
- 2-year warranty · made in Gailhan
Key features
This toroidal transformer 230V 24V, or toroid, steps 230 V mains — formerly 220 V — down to 24 V AC for automation and control: gate motors, irrigation solenoid valves, relays and contactors, 24 V lighting. For the same rating, a toroidal transformer is lighter, more compact and quieter than a conventional transformer, and it mounts with a single centre bolt. It is supplied with its mounting dish; its leads are colour-coded: black for 230 V, red for 24 V. From 50 to 2,000 VA.
This 24V toroidal transformer supplies 24 V AC. If the device's rating plate says “24 V DC”, “24 VDC” or “24 V ⎓”, it needs a 230 V / 24 V DC power supply (motors, door strikes, batteries) or a 24 V LED power supply (LED strips, electronics).
It is installed in an enclosure or cabinet, in a dry place, with air around it: it gets warm in normal operation.
The centre bolt must never touch both the metal base and the metal lid of an enclosure: it would form a shorted turn, which destroys the transformer.
When should you use a 24V toroidal transformer?
- 24 V AC motors for gates, garage doors and roller shutters.
- Solenoid valves and automatic irrigation controllers.
- Control and regulation circuits: relays, contactors, thermostats and valves running on 24 V AC.
- 24 V AC lighting: halogen lamps and spotlights designed for this voltage.
- Doorbells, intercoms, electric door strikes and alarm panels running on 24 V AC.
- Replacing an original 230 V / 24 V toroid in an automation system, alarm or control panel.
This toroidal transformer 230V 24V supplies AC: for 24 V DC (DC motors, LED strips, electronics), choose a power supply.
Wiring the toroidal transformer
The colour code is repeated on the transformer label.
- Switch off the powerWork with the supply isolated and the circuit breaker open.
- Black leads to 230 VThe two black leads to line and neutral, behind a time-lag (T) fuse or a type D circuit breaker.
- Red leads to 24 VThe two red leads to your 24 V equipment, using cable of a suitable size for the length of the run.
- Mount itSit the toroid between its washers, cap it with the mounting dish and tighten the centre bolt without crushing the winding.
Testing the transformer. With the power off: continuity between the two black leads and between the two red leads, none between a black and a red. With the power on, by a qualified person: slightly more than 24 V off load on a multimeter set to V~.
Protection on the 230 V side
Time-lag fuse (T)
or type D circuit breaker, rated for the primary current: 0.87 A for the 200 VA. At switch-on, a toroid draws a high current.
Mounting
Centre bolt and mounting dish, without crushing the winding. The bolt must never touch both the metal base and the metal lid: it would form a shorted turn.
24 V side
At 24 V, the current is high: 8.3 A for the 200 VA. Over a long run, work out the cable size.
Ratings and prices
From 50 to 2,000 VA. For another voltage or multiple secondaries, custom-made.
| Rating | 24 V current | Primary current | Diameter × height | Weight | Price ex VAT |
|---|---|---|---|---|---|
| 50 VA | 2.08 A | 0.22 A | Ø 90 × 37 mm | 0.73 kg | €36.32 |
| 100 VA | 4.17 A | 0.43 A | Ø 97 × 37 mm | 1.25 kg | €43.99 |
| 200 VA | 8.33 A | 0.87 A | Ø 110 × 43 mm | 2.7 kg | €57.40 |
| 250 VA | 10.4 A | 1.09 A | Ø 133 × 48 mm | 2.75 kg | €66.99 |
| 300 VA | 12.5 A | 1.30 A | Ø 135 × 45 mm | 2.95 kg | €69.86 |
| 400 VA | 16.7 A | 1.74 A | Ø 145 × 57 mm | 4.1 kg | €84.80 |
| 500 VA | 20.8 A | 2.17 A | Ø 148 × 58 mm | 4.4 kg | €89.56 |
| 630 VA | 26.2 A | 2.74 A | Ø 152 × 60 mm | 4.9 kg | €93.39 |
| 750 VA | 31.2 A | 3.26 A | Ø 160 × 80 mm | 6.4 kg | €95.26 |
| 1000 VA | 41.7 A | 4.35 A | Ø 185 × 80 mm | 8.4 kg | €124.01 |
| 1600 VA | 66.7 A | 6.96 A | on request | 10 kg | €182.97 |
| 2000 VA | 83.3 A | 8.70 A | on request | 11.5 kg | €236.61 |
Catalogue dimensions and weights. Rated currents: rating ÷ 24 V on the secondary, ÷ 230 V on the primary.
Specifications of the 230 V / 24 V toroidal transformer
Values for the selected rating: 200 VA.
- Primary
- 230 V AC, black leads
- Secondary
- 24 V AC, red leads
- Rated secondary current
- —
- Rated primary current
- —
- Duty
- Continuous
- Type
- Toroidal transformer, two separate windings
- Diameter × height
- —
- Weight
- —
- Mounting
- Centre bolt and mounting dish (supplied)
- Connection
- Colour-coded flying leads, wiring label
- Ambient temperature
- 40 °C maximum
- Insulation class
- H
- Thermal protection
- On request
- Standard
- EN 61558-2-6, safety isolating transformers
- Compliance
- CE marking, RoHS
Frequently asked questions
About the 230 V / 24 V toroidal transformer.
How do you wire a 24V toroidal transformer?
With the power off: the two black leads to the 230 V, the two red leads to your 24 V equipment. The colour code is repeated on the transformer label. On the 230 V side, fit a time-lag (T) fuse or a type D circuit breaker.
Toroidal transformer: 220V to 24V or 230V to 24V?
It is the same: 220 V is the former name for the 230 V mains. A 220V to 24V toroidal transformer connects to the same mains supply and gives the same 24 V.
What is the difference between a toroidal transformer and a conventional transformer?
For the same rating, a toroidal transformer is lighter and more compact, mounts with a single centre bolt, hums less and radiates less magnetic field around it. A conventional transformer, with E and I laminations, is fixed with four screws: for cabinet mounting, with a cover or in an enclosure, see the 230 V / 24 V single-phase transformer. Toroid or toroidal transformer: they are the same thing, a transformer whose core is a torus (a ring).
Is it suitable for a gate motor or solenoid valves?
Yes, if they are designed for 24 V AC: “24 V AC”, “24 VAC” or “24 V ~” on the rating plate. For a motor or circuit board running on 24 V DC, choose a 230 V / 24 V DC power supply.
Is it suitable for 24 V LEDs?
For LED lamps marked “24 V AC” or “AC/DC”, yes. LED strips and spotlights marked “24 V DC” need regulated DC: choose a 24 V LED power supply.
Which rating should I choose?
Add up the power of the equipment supplied at 24 V, multiply by 1.25 and take the next rating up: 150 W of solenoid valves and control circuits needs 188 VA, so a 200 VA toroidal transformer. The calculator above the table does this for you.
Can it be installed in a junction box?
It is not recommended: it gets warm in operation and must remain accessible. Install it in a sufficiently large, ventilated enclosure or cabinet, fixed with its mounting dish; a mounting plate lets you fit it on a DIN rail.
How do you test a toroidal transformer?
With the power off, an ohmmeter should show continuity between the two black leads and between the two red leads, and none between a black lead and a red lead. With the power on, by a qualified person, a multimeter set to AC (V~) reads slightly more than 24 V off load between the red leads.
Why is the off-load voltage above 24 V?
A 24V toroidal transformer is designed to give 24 V on load: off load, its voltage is slightly higher. It returns to 24 V when the equipment is running.
What protection on the 230 V side?
A time-lag fuse (T) or a type D circuit breaker: at switch-on, a toroidal transformer draws a high current, which a fast-acting fuse or a type B breaker cannot withstand. The rating is chosen from the primary current, given in the ratings table.
Can I get 24 V DC?
Not with this toroidal transformer 230V 24V alone: it supplies 24 V AC. Choose a 230 V / 24 V DC power supply for motors, door strikes or battery charging, or a 24 V LED power supply for LED strips and electronics.
Is there a custom version?
Yes: other voltages, multiple secondaries, from 50 to 2,000 VA, on the custom toroidal transformer page.
Customer reviews
Reviews posted by customers who bought this transformer (in French).
Reçut dans un bon emballage, fonctionne très bien, ne peut que recommander.
reçu rapidement et très bien emballé , service conseil renseigne tres bien pour l achat, site achat a recommander
Prix très correct pour un article français
Correspond au besoin, livré rapidement
Très bon rapport qualité/prix
conforme a ma commande
Other toroids and alternatives
Other voltages, custom builds, and solutions in a sealed housing or for DC. See all our 230 V to 24 V transformers.