Usually halogen bulbs in the 600-1000W range last a few hundred hours maximum.
I once blew out four 800W bulbs in Arri pars because we were using them in a hot building in summer and we had them running for 12 hours straight. The bulbs weren't new, but they went out one after another during the last hour or so - I guess it was the summer heat (like 40-45°C in the building) and the continuous use of the eng fixtures.
We also have 1kW par eng fixtures from Gunlux which you better don't move much while on because the 1kW bulbs blow out very quickly if you move them too roughly. Put 650W in the same fixtures and you can move them as much as you like.
I once blew out four 800W bulbs in Arri pars because we were using them in a hot building in summer and we had them running for 12 hours straight. The bulbs weren't new, but they went out one after another during the last hour or so - I guess it was the summer heat (like 40-45°C in the building) and the continuous use of the eng fixtures.
We also have 1kW par eng fixtures from Gunlux which you better don't move much while on because the 1kW bulbs blow out very quickly if you move them too roughly. Put 650W in the same fixtures and you can move them as much as you like.