Street Light Fusing

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miroslaw

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Some areas of Canada have implemented new safety requirement that each outdoor steet light pole luminary must be fused. Mostly used is buried service. Utilities & municipalities working on solutions (they vary). Solution now uses fuse in pole.
Has anyone heard anything like this in the USA?
 
Re: Street Light Fusing

What is the reason for the local fuse as intended? Do they run an equipment grounding conductor with the supply, or are they relying on a ground rod to clear faults? If so, the fuse will not blow, unless it is set for low single digit amps.
Karl
 
Re: Street Light Fusing

I can see the benefit of a fault being limited and isolated at the pole itself. This could prevent entire circuit shutdown when only one pole has a problem.

I have not personally seen this required or even requested. :)
 
Re: Street Light Fusing

This is very common in PA. When I used to work for the Commonwealth of PA, I spent a lot of time on hightway and interchange lighting. Typically an inline fuse is used in the T-base or hand hole. We used a a fuse in the range of 3-7 amps depending on the ballast requirements for the HID lights in use. Its been a while, but I think it was a Bussman FNK or FMK and the matching inline fuse holders. The complete setup for each light is quite expensive.

We ran an ECG to each pole from the service and bonded the pole. The fuses actually worked really well. Just expensive to maintain.
 
Re: Street Light Fusing

We have always used an inline fuse with the holder and boots to keep all the other lights in the circuit on and to provide a disconnecting means for the individual column. On the other hand, our grounding is to the neutral.
 
Re: Street Light Fusing

Our neutral feed comes into a block and the tail is taken directly to the column (I am discussing aluminum columns). Each column has a Ufer when you consider the anchor bolts are directly imbedded. From that point, the neutral is taken up the column to the fixture.

The phase wire is also taken to a block and terminated. Another conductor is taken from that block, into a fuse, and continues on to the fixture.

Losing the neutral is as devastating to us as having a lost neutral in a piece of equipment or feed to a light in a plant. The same thing happens and the light is lost. Yes, the shell becomes hot in the same manner as a high bay light. :(

It is interesting to note that we just don't loose our feeds to our lights. The minimum size is #6 duplex and we loose it because of dig ins, not because of bad connections. :D
 
Re: Street Light Fusing

the national electric code should step up to the plate and standardize "street lighting" and for that matter any electrically energized pole over 30 volts! too many people are killed by energized matallic surfaces every year!
 
Re: Street Light Fusing

The NEC does standardize street lighting. However, the majority of street lighting is in the street rights-of-way and is covered by the NESC. The NESC also standardizes street lighting. The problem is when neither of these standards are followed nor proper maintenance is done on a regular basis.

What I am really saying is that neither Code is good enough if the installations are done with poor workmanship, not following the rules laid out in them, and not following up with proper maintenance. Proper maintenance is not just making it work when it doesn't put out light anymore. Whenever service is done, the whole installation should be looked at for any deficiencies that have developed. :D
 
Re: Street Light Fusing

Its fairly common to fuse roadway lighting at the base of each pole. Some times the fuse holders are breakaway type if the pole is knocked over the fuses pull apart. Also fuses prevent a ballast problem from taking out the entire circuit.
"the national electric code should step up to the plate and standardize "street lighting" and for that matter any electrically energized pole over 30 volts! too many people are killed by energized matallic surfaces every year!"
Street lighting is in the scope of the NEC. The TCC made that very clear in rejecting a proposal to add street lighting to the scope of the NEC, as it already is.
The comment above relates to poor installation and maintenance practices, which can happen under the NEC or the NESC. One of the problems with street lighting is the design (on the NEC side) is most often done by a civil engineer. This is not to say a civil can't get it right (I know Washington State DOT does an excellent job), but often the rules are bent or ignored.

Tom Baker, Member Illumination Engineering Society Roadway Lighting Committee and Code Corner column author for the International Municpal Signal Association Journal.

[ June 04, 2004, 06:03 PM: Message edited by: tom baker ]
 
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