Restarting the HID

I know your supposed to wait for a while before restarting a HID. I was wondering why exactly? Are you waiting for the bulb to cool, or the ballast? You would think the bulb would cool off really fast.

It all depends on the components. Some systems can do "hot restrike" all day long, others like 30-60 seconds to cool down, some systems need 10-20 minutes (typically 400+W "bay lights").

AE 24w is for sure and I think the Brightstat 24w is also a hot re-strike.
Dave

Just out of curiousity, what happens if you try to fire up too soon on a non hot start light? Will it pop the bulb?

I think that restarting too fast on a non-"hot restrike" unit is mostly hard on the ballast.

Soniq7 said:

Just out of curiousity, what happens if you try to fire up too soon on a non hot start light? Will it pop the bulb?

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Our theatre has metal halide worklights that are used during load in, hell week, etc. Before / intermission / after the show usually has the halogen floodlights on the ceiling, but we have metal halide high output fixtures for work.

If they get turned off, you gotta wait 10 mins before turning them back on. If you turn them on too soon, they start making this arcing "BUZZZZZZZZ" noise and the bulbs flicker these orange looking sparks of light. Definitely not good.

what about for those with the costco and hf HID's how long should we wait?

What happens if you try to hot-restike a non hot-restikable lamp with a non-hot-restike ballast is that it won't arc because the ballast can't produce a voltage high enough. When the heat builds up in a HID lamp, the pressure increases so the voltages needed to arc gets higher. If you leave it like that, you will enter what's called glow state, where the lamp is keept glowing as the ballast try to ignite the lamp constantly without succeeding.
If you on the other hand have a hot-restrike ballast and a non-hot-restikeable lamp is that the lamp will ignite but as the electrodes in the lamp are not designed for such forces so it will not last as long as it should.

Good answer, thanks fellas.

Hello,

the problems of a hot restrike are:

1) the elektrode is still hot. A hot restrike will damage it more than a cold one
2) the pressure inside the bulb is still quite high. A hot restrike will rise the pressure to a dangerous limit for the bulb

Both things will lead to an early dead of the bulb. A hot restrike does ALWAYS shorten the lifetime of the bulb. That has got nothing to do with the possibility to do so. Even if it is possible, you should not do that. You can easily the bulbs lifetime by waiting at least 2 minutes (4 minutes is better) before you start the system again.


Greetings, Michael