High-Current Arc Ignition (HAI) Test Apparatus (UL 746A Clause 33).

The High-Current Arc Ignition (HAI) Test Apparatus rates how readily an insulating material ignites when exposed to repeated high-current arcing close to its surface — the test method of UL 746A Clause 33. The same arc-ignition data is referenced by equipment safety standards such as IEC 62368-1 when material flammability has to be characterised.

A pair of standard electrodes — a fixed chisel-tip rod and a moving conical-tip rod — opens and closes against the sample to draw an arc at a controlled current and power factor. The number of arcs the material withstands before it ignites determines its performance-level category. Arc count, separation rate and current are controlled, and an ignition sensor with a preset arc counter stops the test automatically.

ULMEKA designs and manufactures this apparatus. Electrode geometry, the arc current and power-factor range and the control system are built to the test method and the materials under test; the exact configuration is defined during the quotation stage.