Originally Posted by AnthonyAGT
I was asked to replace/ repair 175 watt metal halide fixtures in an underground garage , I havent visited the site yet but was given the lamps and count by the super he also had given me a smaller lamp that was in a small number of the fixtures as well. I am assuming this is an emergency lamp am I right? Any help is appreciated
There are few differnt verison of 175 W MH they do come in pulse start or probe start as Harry say if you have the ANSI number go from there.
For the quatz bulb IIRC typically either 100 or 150 watts quatz with DC concant base type and as John R mention very clear on quatz bulb do not touch it with your bare hand use the rubbing achoal or other means to keep the oil film off the quatz bulb.
There is a cold start or restrike mode ballast which what it does when first the luminaire come on the quatz bulb come on until the luminarie get about 60% brightness it will drop off ( turn off ) but there is other verison is emergecy bulb which it will be wired seperated from normal circuit if that the case you will have to pay attetion to the connections.
And also if you have to replace the ballast expect this is not a normal stock item you may have to order it ahead of the time if you supect bad ballast this is true with restrike verison ( with quatz bulb ) and one warning here you will have to heed on this is the circuit loading capaitcy this part will get ya in surpise if you wondering why few HID luminaire on that circuit so give ya a head up on that.
So just be prepared for anything will show up when you do this.