Comelit Low Voltage Transformer, 230V to 12V AC, 900 mA, DIN Rail 1200

What this transformer is for

Door entry equipment does not run straight from the mains. A transformer sits between the two, and this one belongs to Comelit's door entry power supply range.

It suits installers building or repairing a door entry system, and building managers who need to replace a failed unit like for like.

What the figures mean in practice

• Primary and secondary: the primary winding is the mains side and the secondary winding is the low voltage side. Here that means 230V in and 12V AC out.
• 900 mA: this is the most the secondary is rated to deliver, so add up the current your equipment draws before relying on it.
• 12V AC: The output is alternating current. Equipment that needs DC must not be connected to an AC output.
• 3 DIN modules: this is the width it takes on the rail, so check the enclosure has that space free.

Installing it

The primary side carries mains voltage. It should be isolated before work and connected by a competent person.

The body is plastic and the operating temperature is -5 to 40°C, so choose a dry enclosure away from heat.

Planning your system

It is matched to system types, not individual units. Check the part you are powering calls for a 12V AC supply, using its own instructions.

Other parts for the job are in the door entry and intercom systems range, with more supplies among the access control power supplies.