Sizing fuses for 400w ballast kits

[ssandoval]

For the sake of argument, lets say the load info on the core is missing; how do you calculate the FLA for a 400w/ 480v metal halide kit? What calculation would you use to size fuses? Is there any peak or "in-rush" associated with a ballast powering up?

 

[barbeer]

400/480=.83

I am pretty sure there is capacitance to take care of the in-rush for the most part. Fuses are not required but always good practice(at the base of the pole that is):grin:.

If it were me, I'd use 2 or 3 amp cartridges.

 

[ssandoval]

Yeah, our district's specs require fuses in all pole bases. Problem is, they fused them with 2 amp fuses and most have blown. We re-fused them with 6 amp fuses and had no problems for over a month now. I can't figure out they would blow 2 amp fuses? Anybody?

 

[iwire]

Go on the advance ballast web site and look up a similar ballast. The cut sheet will provide a recommended fuse size for each voltage that the ballast could run at.

We use 2 amp Class CC fuses for 480 volt 400 watt HID fixtures and 5 amp CCs for 1000s at 480.

 

[Cow]

Fusing individual lights/poles is a huge troubleshooting timesaver. We have several hundred low bay lights we maintain in some dairy barns, it's a pain to find the one ballast that shorted out and took the whole string with it.:roll:

 

[Mule]

You didnt really say that is was a pole light, and if its not, and fixtures are just mounted here and there, AND, if area classification permits, I have drilled a 1/2" hole in the fixture side and mounted a Panel mount fuse holder....Little fuse, or Buss holder...pretty handy.....as already stated this will save troubleshooting and keep the rest of the string "on" after a ballast failure........OOPS with 480 the fuse holder mounting hole will be bigger than 1/2" "MY BAD"

 

[steveng]

has anyone fused light poles already installed

has anyone fused light poles already installed

have you done a job where the customer requested fusing existing parking lot
pole lights?

is this a complicated job? cost effective?

say about 40 poles in a multi bldg complex?

 

[mdshunk]

have you done a job where the customer requested fusing existing parking lot
pole lights?

yes. no. well, sort of. After I explained the benefits, they asked me to do it.

is this a complicated job?

No, not at all. There are inline fuseholders made specially for this purpose. They go in the handhole.

cost effective?

say about 40 poles in a multi bldg complex?

Well, compared to a drawn out service call playing "find the bad ballast" for 2 days, yeah, it probably is cost effective. Enhanced security is a selling point too. Instead of a bunch of lights going dark if one of the ballasts craps out hard, you'll just lose one fixture.

 

[peter d]

I've installed the in-line fuseholders to fuse down a whole bunch of VAV's that called for less than a 20 amp circuit. They are beyond simple to install.