I have been at this strip mall and I never noticed that this light, lighting a drive by ATM machine, has a 75 tag! See here for a pic of a 750w HPS lamp.
I have seen the 750w lamp listed in catalogs as an option but didn't think they made any, well they did! @Ian, GE chose this size because they stopped making the M1000 in the 80s and also the 750w lamp uses the same bulb size as the 400w merc so it fits right in.
Philips used to, or maybe still does, make a 1000w HPS lamp in an ED37 envelope which had two 500w arc tubes in series. Never heard of one being used in a 400w sized cobrahead, save for the Sylvania B2255 which was available in 1000w metal halide.
Well, the R2/A2 was larger than an average medium fixture, so it may not affect it as badly, but yeah, it would take a toll on the ballast and lamp life. I've seen 400w HPS M-250A2s before.
I wonder, could a cobrahead could be mounted on a highmast pole? That'd be a cool sight, though due to crazy vibration, screws better be used rather than latches....
That would be an interesting sight! I have never seen it anywhere though but have pondered the idea before. Highmast fixtures have latches too, I'm sure vibrations would be no problem as long as the fixtures have 4 bolt slipfitters.
I've never really had a good look at highmasts since they're virtually extinct around here. I'm sure using cobraheads would be cheaper too, but since they're designed to light large areas at lower mounting levels, the distribution might not be good.
Here they are replacing all the cobras they can with highmasts, they still use 2 inch mast arms so there no reason a cobra couldn't be mounted to them.
@Mike, did RI take down the few high masts they had? I remember seeing metal halide high masts around the interchange of I-295 and US 6 if I recall correctly.
There used to be highmasts on Rte 295 at Exit 6, but they were taken down. I thought they were mercury vapor, but they were taken down around 2008-2009. There used to be highmasts here There are still MH (or MV) highmasts at exit 7 on I-95 and HPS ones in front of the Providence Place Mall at Exit 22 on I-95