Siemens Ignition transformer ZE 30/7 00415539

This Siemens ignition transformer, model ZE 30/7, is a 1-pole step-up transformer used to create a high-voltage electric arc for igniting a combustible mixture. With a primary supply of 230 V at 50 Hz, its secondary delivers 7 kV at 30 mA. The mains voltage is stepped up to the level needed for a spark across the ignition electrode gap. The standard power cable length is 100 mm. It is energised only during the ignition period under command from the burner control.

Replacement ignition transformers of this type are selected by secondary voltage and current, primary voltage, duty cycle, mounting and terminal type, and ignition-cable connector pattern. Before ordering, the primary voltage and output kilovolt rating must match the existing system. Common primary voltages include 230 V, 110 V and 24 V, and the cable between the transformer and electrode is silicone-insulated; the connector diameter and supply cable length must also be compared with the old unit. Observe the correct mounting orientation to avoid moisture ingress.

Ignition transformers have no moving parts and fail electrically, usually from an open primary winding or a shorted secondary, or mechanically from a broken terminal. A hardened or cracked wiring cable can leak the spark to earth, which mimics a faulty transformer and leads to ignition failure. Before condemning the unit, check the ignition cable and the electrode gap, as cable damage or an incorrect gap can produce the same failure signature.