at these above comments.

It was MV! I know this part of Boston and lots of the old street lights are MV. And I do not think they would make it HPS from MV. And makeing it HPS and not giveing a HPS tag! NO!

OH NO! You revived the M-400R2 MV vs. HPS thread!!!

Was this replaced? If so, if the new light is 250W HPS, then this was likely 400W MV. However, if the new light is 400W HPS, it's likely that this light was also 400W HPS. Then again this light may have been 250W HPS and so is the new one... And they may have repalced the 400W MV with a 400W HPS. NGrid does that sometimes... I guess we'll never know.

BTW, are you SURE you didn't see a cycling HPS lamp David?

Uh oh... We have to turn this into a shoebox thread STAT!!

Duquesne Light replaces their 400 watt mercury vapor street lights to either 250 watt HPS or 400 watt HPS.

Let me ask you a question: How many components does the Mercury Vapor bulb use and how many components does the High Pressure Sodium bulb uses?

MV needs three: ballast, cap, and ignitor
HPS only needs a ballast.

Good! now David does not have to be upset by you people.

We Gulls need to make a "NEMA Side Up Association" We Gulls are sad we can not view NEMA tags from atop nor use NEMA tags as a target point!

You want landing pads on that NEMA tag too?

@joe_347V: I thought the Mercury Vapor bulbs use the ballast and the capacitor only

Eye makes a special pulse start MV that needs an ignitor to start. Oh and MV can also run using just a ballast, 240-277v reactor ballasts and 120v HX ballast don't require a cap.

As for the HPS, the retrofit lamps only require a HX or reactor MV ballast.

@ rjluna2: if you took the time to click the links you'd know.

My god people.quit being so darn hard on eachother. ..we are all human it does nOt even matter if it is MV or HPS

Good choice on image Joe, Apple Bloom IS best pony! Lol.

I honestly have no side on this whatsoever. xD I have no idea what this was, there i no explanation. Let's settle with this: We dunno if this is MV or HPS and there is no telling what it was! You would have to see the label to proove it.

Oh brother.

Anyways, yeah Ian's right. We have no way of telling for sure what this is. It sure as hell looks like HPS to me and the 20 or so people between LG and GoL that have looked at this but we'd need to see the label itelf for proove and this thing probably got turned into a cast aluminum waffle by now so...

I won't clearly affirm anything but here's my 2¢:

- The capacitor seems to be connected to its own coil on the ballast (no wire to the socket), making it a Regulated Lag ballast. Those tend to be HPS in general.
- Just under the cap I see a piece of some sort of holding bracket, maybe this used to hold an ignitor.

I don't say the fixture has always been HPS, but it's possible the fixture was retrofitted to HPS, maybe weeks or months before losing parts. Even if David saw the fixture working back in 2005, it was 6 years ago from the moment he pictured it! Just saying here...

Yeah, I guess we can never really say for sure what light source it used but a lot of people on here do have some valid points and logical explanations. But really the evidence in the picture strongly suggests that the light at the point was HPS.

And Vince does offer a valid suggestion about how the light could have be retrofitted from MV remember that NEMA tags might be wrong in that case.

Thanks, Mike (Streetlight98)

I replaced a R2 that was damaged by a TC, a 200w HPS, it had a cap and a plug-in type ignitor with a ballast about this size.