Din Rail Mounted Circuit Breaker is Exposed.

[Cjmccarthy]

This is in a FDOT cabinet, it is a 120v 15amp breaker. is this NEC compliant being mounted on a din rail with no protection? Below is the picture of the circuit breaker and the cabinet it is in. These are FDOT cabinets that are along the roadway and they are locked, so the only person that can access it is an FDOT representative.

 

[petersonra]

It is only exposed if the door is open. No different than taking the cover off a panelboard IMO.

Only authorized persons are allowed inside anyway.

 

[Cjmccarthy]

It is only exposed if the door is open. No different than taking the cover off a panelboard IMO.

Only authorized persons are allowed inside anyway.

Authorized personnel, but they are not electricians. Most of the time, they are doing preventative maintenance, so they are entry level not even a technician. That is my concern.

 

[petersonra]

Authorized personnel, but they are not electricians. Most of the time, they are doing preventative maintenance, so they are entry level not even a technician. That is my concern.

What rule says they have to be electricians? Or technicians?

 

[EC Dan]

To his point, there is no title requirement but anyone opening the door must be Qualified since they will immediately be within the limited approach boundary when opening the door and potentially the restricted approach and arc flash boundary as well. Refer to 110.2 in NFPA 70E.

 

[Cjmccarthy]

To his point, there is no title requirement but anyone opening the door must be Qualified since they will immediately be within the limited approach boundary when opening the door and potentially the restricted approach and arc flash boundary as well. Refer to 110.2 in NFPA 70E.

My point exactly, is there anything that can be done to make it safe. the people going into these cabinets, some of them don't know what a circuit breaker is. I just want to make sure everyone is safe.

 

[jim dungar]

... the people going into these cabinets, some of them don't know what a circuit breaker is.

They need proper training. This is an NFPA70E electrical safety issue not an NEC issue.

 

[EC Dan]

My point exactly, is there anything that can be done to make it safe. the people going into these cabinets, some of them don't know what a circuit breaker is. I just want to make sure everyone is safe.

It depends on what PM is going on in there. My guess is at least some of the PM involves those batteries, which means reaching into the panel. Proper training and PPE is going to be a far cheaper and more effective solution than trying to "idiot proof" this thing.

 

[g-and-h_electric]

IF this is 120 Volt, why is the breaker opening both hot and neutral?

Also, why does it look like the GROUND was removed from it's lug and connected to the breaker? Isn't the ground NEVER supposed to be disconnected?

Just my observations...


Howard

 

[petersonra]

IF this is 120 Volt, why is the breaker opening both hot and neutral?

Also, why does it look like the GROUND was removed from it's lug and connected to the breaker? Isn't the ground NEVER supposed to be disconnected?

Just my observations...


Howard

You are allowed to disconnect both the hot and neutral as long as it happens at the same time.

I can't say I have ever seen someone hook a ground up to a circuit breaker pole before.

I cannot tell for sure if there is a green wire on the top of the 3rd pole of the Cb or not. I see some green but the picture is pretty blurry at that spot.

 

[LarryFine]

No different than contactors and the like.

 

[Cjmccarthy]

You are allowed to disconnect both the hot and neutral as long as it happens at the same time.

I can't say I have ever seen someone hook a ground up to a circuit breaker pole before.

I cannot tell for sure if there is a green wire on the top of the 3rd pole of the Cb or not. I see some green but the picture is pretty blurry at that spot.

Yes, the Black, White and Green wires are connected to the breaker at that location. at another location, the black goes to the breaker and the white and green wires go to a terminal block.

 

[tom baker]

The internal wiring of traffic signal cabinets is not often inspected by the HJ. Typically none of the components in the signal cabinet such as loop detectors, load switches, conflict monitors and single controllers are not UL listed. In Washington state the electrical AHJ only inspects the electrical service. Inside the cabinet the wiring is done by the local municipality and they take responsibility for the wiring by our state codes. Who can do the wiring inside a single cabinet and who has the ability to open the single cabinet is determined by the agency. Perhaps having a key to the door makes one qualified. The issue that the OP post pointed out is best handled by internal policies or training. I wrote electrical code articles for the IMSA journal, a national traffic signal magazine, for many years and have taught many classes to traffic signal technicians. Some agencies follow the code and some do not, believing they are exempt from the NEC. But it does appear to be there are some electrical issues with the wiring in that cabinet.

 

[tom baker]

And when you look at the wiring from the load switch, which is what turns the signal head on to the head you’ll notice that the green wire is fused. That’s because the IMSA five connector signal cable is black white, red, black, with a stripe and the green is used for a green lamp. There is now an exception in the NEC in the section for identification of the equipment grounding conductor that allows that green to be used for other than a equipment grounding conductor but the first time you see a green wire with a fuse you have to look twice.

 

[tom baker]

This is in a FDOT cabinet, it is a 120v 15amp breaker. is this NEC compliant being mounted on a din rail with no protection? Below is the picture of the circuit breaker and the cabinet it is in. These are FDOT cabinets that are along the roadway and they are locked, so the only person that can access it is an FDOT representative.
View attachment 2561722 View attachment 2561723

Typically the NEC does not apply to the internal wiring of a traffic signal cabinet, unless it’s UL 508A listed or similar. The cabinet itself may be listed. Most signal agencies push back against having listing labeling and inspections of equipment.

 

[Cjmccarthy]

Typically the NEC does not apply to the internal wiring of a traffic signal cabinet, unless it’s UL 508A listed or similar. The cabinet itself may be listed. Most signal agencies push back against having listing labeling and inspections of equipment.

This is an ITS cabinet and the FDOT specs reference the NEC. When a PM Tech does his work, he wipes everything down with a rag, sometimes that rag is damp. I just thought there might be a NEC code I could use. I am still searching the Spec. Thank everyone for their help.

 

[paulengr]

Buy sheets of FR3 “glastic” fiberglass and cut holes for the breakers so you can cover everything else. Or use plexiglass or lucite or lexan. That’s one option. Here is another:

Shopping

www.factorymation.com

You can get bus bars for these too as a “DIY” distribution panel. Many vendors carry them. DIN mount with finger safe terminals. You can get them in nearly any rating or voltage or number of poles. Bus bar:

Shopping

www.factorymation.com

That’s how I’ve been doing panels. Very happy with the result. Very clean.

Old school was bolt breakers to the back of a swing out door or poking through it. Lots of work getting spacing right.

 

[tom baker]

When the ITS cabinet is made, what specs do they use?
In the NEC, products such as panel boards, are made to a UL standard, for safety. To know how to apply the NEC, we would look in definitions to determine what it is and then look for the article.
I suspect that in the ITS cabinet most of the products, like detector racks are not listed.

In the signal cabinets I worked on, there were plexiglass shields on 120 volt terminals. I would suggest using IEC style circuit breakers, fuse holders, etc as the terminals are touch safe, The trend was to IEC touch safe equipment as its readily available and easier to install on DIN rails

You should identify who is allowed to access the cabinets, have appropriate training and signage

 

[petersonra]

Buy sheets of FR3 “glastic” fiberglass and cut holes for the breakers so you can cover everything else. Or use plexiglass or lucite or lexan. That’s one option. Here is another:

Shopping

www.factorymation.com

You can get bus bars for these too as a “DIY” distribution panel. Many vendors carry them. DIN mount with finger safe terminals. You can get them in nearly any rating or voltage or number of poles. Bus bar:

Shopping

www.factorymation.com

That’s how I’ve been doing panels. Very happy with the result. Very clean.

Old school was bolt breakers to the back of a swing out door or poking through it. Lots of work getting spacing right.

I like the IEC style MCBs too. The doodads you can get for them like the bus bars make life a lot easier. the bus bars are also available for small fuses like class CC. Note how clean the bus bars make the feeder wiring.



I am not a big fan of trying to cover stuff with insulation as a means of personnel protection. It can be done but I am not 100% sure it is really all that much safer when you are done. For instance, many of the installations I have seen with plexiglass covers just have a flat piece of plexiglass over the part. It is still possible to grab around the edge of the plexiglass and hit an energized part. better are plexiglass covers bent around the part so it is harder to get at the energized part. Plus they tend to get in the way and people remove them to work on stuff and then just leave them off.

 

[paulengr]

When the ITS cabinet is made, what specs do they use?
In the NEC, products such as panel boards, are made to a UL standard, for safety. To know how to apply the NEC, we would look in definitions to determine what it is and then look for the article.
I suspect that in the ITS cabinet most of the products, like detector racks are not listed.

In the signal cabinets I worked on, there were plexiglass shields on 120 volt terminals. I would suggest using IEC style circuit breakers, fuse holders, etc as the terminals are touch safe, The trend was to IEC touch safe equipment as its readily available and easier to install on DIN rails

You should identify who is allowed to access the cabinets, have appropriate training and signage

I doubt it’s not Listed but there is a complication even with UL.

UL Lists TWO kinds of equipment. With the breaker I linked to it comes in two varieties, UL 1077 “supplemental” and UL 489. The difference is that one is a component and considerably cheaper. It will say “RU” if it is UL Listed. The other is a Listed Assembly, with a UL label. The difference is that if I’m a manufacturer of say widgets and I build a breaker into the widget then I send several samples off to UL for testing and if it meets product safety testing, I can put a big UL “assembly” sticker on my widgets. Components are basically a pass through…it’s a raw material stamp. It should not be used in a panel unless you build a bunch of prototypes and send them to UL for approval. My guess is these might have been built by the “lowest bidder” and knowing it falls outside NEC they used cheap component grade breakers if that’s the case.

Other testing labs are out there. The system works the same with them,