Fuse experts, I have a question.

[bassbone52]

Our church parking lot has 19 metal halide lights. Nine lights are currently not working. I opened up the access cover on two of them last night and found two FNQ-5 fuses in two separate fuse holders. In both poles, one of the two fuses had blown. Went to Home Depot and found FNM-5 fuses. Could I use those instead of the FNQ-5? Any idea what might have caused these fuses to blow? I'm guessing I'll find blown fuses in the remaining seven lights.

I've read that burning metal halide bulbs for less than 10 hours at a time can shorten the life by up to half. Ours burn for 2-3 hours around dawn then again around sundown. Should I just just let them burn all night?

Thanks

 

[rockwithjason]

The differnce in the two is the voltage rating. Those lights are probably 480v and a 250v fuse would be missapllied. Get the right fuse from an electric supply house. The question on burn time is subjective. If you want to pay the cost of burning the lights all night you can buy i am willing to be that you wont make your money back on lamp life. I would let it ride and then change them out as they fail to a screw in led conversion

 

[wyliesdiesels]

What is the system voltage that the lights are operating on?

What is the ballast rating?

What is the required interrupt rating of the supply?

U need to know these things before u can select the proper fuse...

As said above the voltage ratings of the 2 types are different.

An FNM-5 is rated at 250vac...

An FNQ-5 is 500vac or less though that model isnt listed in the following catalogue: (There is a FNQ-R-5 which is rated at 600vac or less)

http://www.eskc.com/v/vspfiles/assets/images/22_fuses&circuitbreakers.pdf

 

[bassbone52]

These lights are 208v per the plans. Seems like the FNM-5 would work based on that. Don't know about the ballast or interrupt rating. If we can use an LED bulb instead, that would be fine. It uses an Edison type screw in.

 

[Gummi Bear]

For what a LED lamp (bulb) costs nowadays, you can replace the whole head with an LED. There are tons of options, for just about any budget, and light output needs.

Talk to a local electical contractor about what is available and what it will take to make the conversion.

Also - keep an eye on city ordinances that may have "light pollution " standards in place. You may have to order deflect shields or different optics to satisfy these requirements

As for the fuses, yes, you need to stick with the correct voltage class, and if you know what the wattage of the fixture is, we can determine the correct size of fuse (5a may or may not be correct size). 208 is a multi phase system comprised of 120v legs (3 of them, but most site lighting will be "single phase 208" which is 2 legs of 120)


I went to the woods because I wished to live deliberately - Thoreau

 

[walrus]

For what a LED lamp (bulb) costs nowadays, you can replace the whole head with an LED. There are tons of options, for just about any budget, and light output needs.

Talk to a local electical contractor about what is available and what it will take to make the conversion.

Also - keep an eye on city ordinances that may have "light pollution " standards in place. You may have to order deflect shields or different optics to satisfy these requirements

As for the fuses, yes, you need to stick with the correct voltage class, and if you know what the wattage of the fixture is, we can determine the correct size of fuse (5a may or may not be correct size). 208 is a multi phase system comprised of 120v legs (3 of them, but most site lighting will be "single phase 208" which is 2 legs of 120)


I went to the woods because I wished to live deliberately - Thoreau

There might be state/govt money available to make the switch from metal halide to led . I did hundreds in the last year and customers cashed in on rebate money

 

[screff]

Also with the idea of running the lights all night, on my local poco a lot of churches are on TOU (Time of Use) tarrifs. Your off-peak useage could be fairly inexpensive if your poco/state has similar tarrifing system. YMMV

 

[Gummi Bear]

Good call

I didn't even think about rebate money.


I went to the woods because I wished to live deliberately - Thoreau

 

[rlitman]

For what a LED lamp (bulb) costs nowadays, you can replace the whole head with an LED. There are tons of options, for just about any budget, and light output needs.
...
Also - keep an eye on city ordinances that may have "light pollution " standards in place. You may have to order deflect shields or different optics to satisfy these requirements

A lot of LED lamps take this into account. Partly because they're using new lens designs, and partly because the limited light output of LED requires that stray light be directed to where you want it.

 

[bassbone52]

I'll take a look at the wattage and the ballast/interrupt ratings next time I'm there. I'm sure it's single phase. The lights have only been in place for 1 1/2 years and this is the first time that we've looked at fuses. If the remaining seven lights we haven't checkedalso have blown fuses, it's time we found out why this is happening. FWIW, all the lights that are out are on the same circuit, which is two 20-amp breakers tied together. The remaining lights are on another circuit and they are all working.

 

[wyliesdiesels]

Do the other lights have the same size fuses?

Other possibilities is a ground fault due to water.

Did u have any rain right or recently before the lights stopped working?

U should definitely check the wiring, ballast etc before installing a new fuse as it could blow again and thus be wasted money.

Im curious why these have fuses to begin with. Whats the size of the wire inaide of the pole/on the load size of the fuse block feeding the ballast

 

[bassbone52]

Do the other lights have the same size fuses?

Other possibilities is a ground fault due to water.

Did u have any rain right or recently before the lights stopped working?

U should definitely check the wiring, ballast etc before installing a new fuse as it could blow again and thus be wasted money.

Im curious why these have fuses to begin with. Whats the size of the wire inaide of the pole/on the load size of the fuse block feeding the ballast

I haven't checked the other seven, but the two that were checked all had FNQ-5 fuses, two in each pole.

We haven't had rain for three weeks so it doesn't seem like water is a problem.

Checking ballasts will require a lift rental. There have been no modifications to these since they were set in place 18 months ago. It looks like a #12 wire on the load side going up to the fixture.

 

[wyliesdiesels]

The only other thing i can think of is the ballast shorted out...yes youre gonna need to check out the fixture unfortunately...

 

[bassbone52]

The only other thing i can think of is the ballast shorted out...yes youre gonna need to check out the fixture unfortunately...

Man, I really appreciate the advice. I love this forum.

 

[walrus]

Man, I really appreciate the advice. I love this forum.

I'd look at the other fixtures not working first though. Maybe the fuses are sized wrong?
Metal halide ballasts will definitely let out the magic smoke, seen it many times.

 

[rockwithjason]

the purpose of those fuses is to keep a problem in one pole from taking out the whole string. if you have had storms in the area a lightning strike could be the culprit. I would try fuses in one and if it comes back i would do the rest and then chase any remaining problems

 

[jhelrey]

The LEDs in those look and work great! No clue on price though!

 

[wyliesdiesels]

the purpose of those fuses is to keep a problem in one pole from taking out the whole string. if you have had storms in the area a lightning strike could be the culprit. I would try fuses in one and if it comes back i would do the rest and then chase any remaining problems

Yes i realize that but Ive never seen light poles individually fused.

Ive worked on parking lot lighting at large winerys and none of the poles had fuses....

 

[Gummi Bear]

Yes i realize that but Ive never seen light poles individually fused.



Ive worked on parking lot lighting at large winerys and none of the poles had fuses....

Some municipalities require it. Some engineers just love to spec stuff like this


I went to the woods because I wished to live deliberately - Thoreau

 

[MTW]

Suggestions:

If the fixtures are 1.5 years old they are likely the pulse start variety, which usually means that they contain in addition to the ballast transformer a capacitor and ignitor. The ignitor is usually the first thing to give up. Worn, defective or old lamps contribute to the stress on the ignitors, when the lamps characteristics change due to age. It takes longer for them to start, sometimes multiple re-strikes, before they finally reach operating temperature.

You didn't state what the wattage is only that they are metal halide. 19 fixtures would suggest a large lot, and large fixtures to go with it. 400WMH would be my guess.

Looking up a couple of different manufacture's cut sheets for 400WMH pulse start ballasts. Venture lighting calls for a 6A fuse, Advance calls for a 7A fuse both @ 208V. This may be part of the problem if indeed they are 400W units.

Another thing to check if you have to get a lift is, are the lamps the correct type to match the ballast? There is a ANSI code type on the ballast, M59 for one example, and the lamp type needs to match, for the fixture to operate correctly. Many times I have come across fixtures with the wrong lamp type but correct wattage installed, causing early failure, ballast or lamp.

Check the startup of the remaining fixtures from a cold start at night. Do any do a re-stike before reaching temperature, or glow dimly not getting to full temp? Take an amp reading if you can of the operating units while starting and running. Poor starting performance is usually related to a degraded lamp, stressing the ignitor.

If you find poor starting of several, it would suggest you need a group lamp replacement to prevent future problems. It's cheaper to do it, one time, while the lift is there.

I find that there can be a great disparity in longevity of lamp life from different lamp manufacturers, in my own fixtures. Some last 1.5 years and others 5 years in the 175WMH pole fixtures I run. On a similar operating schedule as you mentioned earlier.

The installer of the fuses did you a good favor by installing them in the base, where ground accessible. Prevents loosing the other fixtures on the string with a short, and keeps the loop on for testing while you service the bad fixtures.

MTW Ω

 

[bassbone52]

Okay, I have a lot to check out before buying fuses, possibly the wrong size, at $20/each. I appreciate all the info.

We have an electrician in the congregation. I'll see what he can do for us.

 

[bassbone52]

the bulbs are 150w. The box is marked E17.
The ballast is M102/M142 metal halide rated
120/208/240/277V and it has a pre-wired ignitor.

 

[wyliesdiesels]

Well then the 5a fuses should be fine.

 

[MTW]

Check the lamp further. E17 is the size and shape of the lamp. You want to make sure that it is a M102 or M142 type rated to match the ballast.

There appears to be 3 different ANSI type numbers for a 150WMH pulse start, you want to make sure your components match.

M102, M142, M81 Recommended fuse size for each type is different.



Check this page for a troubleshooting guide.
javascript:ShowDocument("47682",%20"http://assets.sylvania.com/assets/Documents/TROUBLE_GUIDE1.e82154dc-41bc-4a94-91c8-b7b05f9701d2.pdf",%20"Technical%20Document","Troubleshooting%20High%20Intensity%20Discharge%20Lighting%20Systems%20","Document","450","600");

MTW Ω

 

[bassbone52]

Here's what we have: it's an M102 lamp

 

[MTW]

Looks like their matching M102 lamp and ballast, and the fuse size recommended in the chart above for M102 is 5A@208V. Look's like every thing is correct, time to get out in the lot, and finger it out.

Economical fuse source:
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_sop=15&_nkw=fnq-5&rt=nc

MTW Ω

 

[bassbone52]

Re: Fuse experts, I have a question. (Revisited)

I need to bring this thread back to life. Last January (2019) all of the metal halide parking lot light bulbs were replaced with LED bulbs and the ballasts were removed from the fixtures. These are 208v single phase fixtures. Everything was working fine until fuses started to blow again. There are two FNQ-10 fuses in each light base. I found one blown fuse in six of the 18 light bases. What could possibly be causing these fuses to blow?

 

[Norcal]

Re: Fuse experts, I have a question. (Revisited)

I need to bring this thread back to life. Last January (2019) all of the metal halide parking lot light bulbs were replaced with LED bulbs and the ballasts were removed from the fixtures. These are 208v single phase fixtures. Everything was working fine until fuses started to blow again. There are two FNQ-10 fuses in each light base. I found one blown fuse in six of the 18 light bases. What could possibly be causing these fuses to blow?

Where are the fuses located? At the base of the pole or in the fixture? Check the wiring downstream of the fuses as a start.

 

[grounded-b]

I've seen pole light fuses blow when there is a lightning storm.

A ground strike nearby can cause induced voltage in the underground feeds to the lights.

The fuse is installed to protect the ballast/LED driver

Steve

 

[fitter30]

Fmq fuses rated at 600 volts, fnm fuse rated at 250 volt. You can run a higher voltage rated fuse on lower voltage but not lower voltage on higher voltage. If fuses are blowing could be from wet wiring or bad connections.

 

[DieselNut88]

You could have a chaffed hot wire, rodents chewing on wires, bad ballast, loose connection. Many possible cause. Be careful. Dont get hit by 208v it hurts a little.

 

[Norcal]

You could have a chaffed hot wire, rodents chewing on wires, bad ballast, loose connection. Many possible cause. Be careful. Dont get hit by 208v it hurts a little.

Pretty hard to get hit by 208V unless you grab both legs.

 

[laser3kw]

There might be state/govt money available to make the switch from metal halide to led . I did hundreds in the last year and customers cashed in on rebate money

our POCO helped our fire department switch our outside lights to LED.
darn it! got caught by another zombie thread! (2015)