Loom and the UL inspector
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petersonra
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- Northern illinois
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- engineer
I don't know. Is the loom a listed wireway? If it is not a listed wireway it probably can't be used outside of the cabinet, if at all.
Do you mean UL listed wireway? Does this matter if the Equipment is not UL listed? Here is a link to the loom: http://www.waytekwire.com/item/LCP-500-250/
I do not see a UL listing, but I do see on the data sheet (link on the left) that the material "must be compliant" with the ELV directive (which I take to mean European Low Voltage Directive). Strange wording there, "must be compliant", I would expect to see "is compliant".
We are not going to use the loom on UL chambers because they want it to be listed. The deciding factor for CE is the end result of using the loom...is it safe or not safe. I would like to be able to point to the NEC if I were forced to argue its safety... I would like to use the loom on Non-UL and aslo CE marked equipment.
I do not see a UL listing, but I do see on the data sheet (link on the left) that the material "must be compliant" with the ELV directive (which I take to mean European Low Voltage Directive). Strange wording there, "must be compliant", I would expect to see "is compliant".
We are not going to use the loom on UL chambers because they want it to be listed. The deciding factor for CE is the end result of using the loom...is it safe or not safe. I would like to be able to point to the NEC if I were forced to argue its safety... I would like to use the loom on Non-UL and aslo CE marked equipment.
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I don't know of any section in the NEC or NFPA 79 that would apply directly to split loom tubing as a wiring method. The only places I ever see it used is in vehicle wiring and other consumer products where it is inside an enclosure or cabinet.
IMO, other than the aforementioned use, the simplest explanation of where it can otherwise be used is where it is not absolutely required for the wiring method but is added to provide another "layer" of protection from physical damage.
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Internal to the equipment, where physical protection is not needed and open wiring would have been OK for one.
That is, where it is serving more to dress the wiring for appearance than to protect it from contact or damage.
Also anywhere that the cables and wires involved would be suitable without any sleeve at all.
mgookin
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- Fort Myers, FL
Now I understand what you were saying.
Those fastners have engineering standards and you have to use them within the rated capacity of those fastners. UL does not test those fastners but ASME does and UL accepts ASME's ratings or standards. They're rated for tensile, shear, etc. They all have capacities or limits and safety factors. Even the orientation of the load is considered. Go find a bolt for holding a suspended load in an industrial facility and be prepared for sticker shock.
If you have something UL Listed and you used #10 stainless machine screws and they approved your assembly, you can't just change that on a whim to a #8 screw because that's what's in the shop that day. And you can't change it to brass or plastic on a whim because that's what was available from the supplier that month. If you want the ability to change out those fastners like that, you need to put in your listing submittal "#10 or #8 in stainless, brass, thermoplastic, ..." UL most certainly does look at everyting including fastners when evaluating a submittal.
The moment you deviate from the approved listing, you have no listing.
In the OP's case it seems UL wants protection for those conductors and they won't accept his proposal.
petersonra
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- Northern illinois
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- engineer
UL does not specify fasteners at all for UL508a applications (what I am most familiar with). You do have to follow the manufacturer's instructions though.
UL allows for a lot of latitude in custom made stuff that is not present in things like clock radios or a microwave oven.
UL makes us remove the loom and run bare wire. They say we cannot use it because it is not listed. This all happened several years ago, and I am not sure if the Engineer pleaded with the inspector or not, or just abided. There are refrigeration compressors located inside the enclosure as well, so there is the possibility of moisture. The loom in my opinion only adds extra protection. I understand what you mean if the UL inspector actually made us run different conduit.
All of the wiring is leaving the subpanel and is ran 6 feet or so along the frame of the equipment to the rear and other parts of the equipment. All of the wiring that leaves the sub panel is within an enclosure. I would like to know what the rules are for allowing open wire without any runway or other conduit.
I believe if we fit the rules for no conduit, then we can definitely use the split loom.
All of the wiring is leaving the subpanel and is ran 6 feet or so along the frame of the equipment to the rear and other parts of the equipment. All of the wiring that leaves the sub panel is within an enclosure. I would like to know what the rules are for allowing open wire without any runway or other conduit.
I believe if we fit the rules for no conduit, then we can definitely use the split loom.
For NEC compliance, see Article 725.
petersonra
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- Northern illinois
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- engineer
To the OP.
There are a whole bunch of different UL standards that you might be referring to. They all have slightly different requirements.
If the UL standard you are building to requires something, or prohibits something, you have to abide by that.
Having said that the typical UL inspectors are not perfect and since they inspect to many different standards it is not unheard of for them to make mistakes in what they think is required.
Ask them to tell you what provision of the standard you are building to is being violated. Most UL standards for customized equipment are quite similar to UL508a and UL508a would allow the use of this type of thing as extra protection for the wires. Having said that, UL508a generally would not apply outside of a cabinet unless you have some kind of addition to your procedure that makes it so.
You really need to tell us just what standard you are trying to meet first. If there is anyone here familiar with it, a poster might be able to comment on it directly. Otherwise we are just guessing.
There are a whole bunch of different UL standards that you might be referring to. They all have slightly different requirements.
If the UL standard you are building to requires something, or prohibits something, you have to abide by that.
Having said that the typical UL inspectors are not perfect and since they inspect to many different standards it is not unheard of for them to make mistakes in what they think is required.
Ask them to tell you what provision of the standard you are building to is being violated. Most UL standards for customized equipment are quite similar to UL508a and UL508a would allow the use of this type of thing as extra protection for the wires. Having said that, UL508a generally would not apply outside of a cabinet unless you have some kind of addition to your procedure that makes it so.
You really need to tell us just what standard you are trying to meet first. If there is anyone here familiar with it, a poster might be able to comment on it directly. Otherwise we are just guessing.
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