The Lamp Room

I've just had my first LEL 'Multipulse' type starter fail. It was in a 2' fixture which sees very regular switching, several times an hour, but has worked fine for two years - bravo. Melted the can, overheated with cathodes glowing.

Interesting. Had the lamp gone eol or is it still ok?

You need to put an Arlen EFS120 or EFS600 in now and see how long that lasts

Lamp new in two weeks ago. I'm still impressed with them though, having installed hundreds of starters in the past.

I've just ordered another batch of 100 from them, no failures so far on any I've fitted

I'd love to know how they fail. First guess would be the SCR device (Startlight or whatever). If it loses control and turns itself on every half cycle via some internal current path after breakdown, the continuous conduction of preheat current could cause sufficient self-heating to cause the meltdown. Such overheating concerns would never exist when normal conduction is so brief and intermittent.

As far as I am aware, these power devices use old-fashioned glass passivation, which is not voltage rugged and can fail permanently when subjected to voltage stress. The failure path can conduct current which acts as trigger current to turn the device on without an externally applied gate signal.

If they really fire (as if getting gate signal) and don't just develop some resistive path (that bypasses the component), then they should not heat much in this mode either - The resistance of a conducting SCR is fairly low. Definitely not heat enough to go out with a bang in a blink (if anything, slow heating and melting the Plastic starter enclosure would be more likely)

I thought slow heating and melting was the failure mode. A flash and a bang sounds more like an electrolytic with mains on it.

I do recall "flash and bang" case with an EFS600 that was presented on LG. First thing i thought when i seen that was "ballast shorted"

Also, there are some 58W fittings with early (1987-ish) EFS600's that i saved from the ballast factory. There is what looks like minor melting in the Plastic cases near the corners of the SCR. I have not tested them yet, i'll test and see if they work at all