20A 240VAC single phase receptacle, window AC unit with UL listed 30A 240VAC single phase plug with GFI. The cord on the AC was replaced with a 20A plug wo/GFI. Other than NEC 422.10 and 11 and some sections of 440. With specific interest in section 440.55.B 'cord and plug shall not exceed 15A at 250VAC'. If I'm reading 440 correctly UL's rating didn't comply with the NEC article. Then there is the issue of downsizing the cord... I'm looking for some rock-solid guidance IRT modifying a UL listed item. Once again I'm trying to overcome the, "if it works now, just leave it alone thought". Overall at best the 20A CB may experience overheating along the conductors. Along with nuisance trips due to an overloaded circuit. Any thoughts
What authority governs modifications to UL listed equipment?
- Thread starter VinceS
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- Massachusetts
110.3(B)
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- Location
- Logan, Utah
VinceS said:
440.55 is titled "Cord-and-Attachment-Plug-Connected Motor-Compressors and Equipment on 15- or 20-Amper Branch Circuits." This section does not apply to equipment designed to be attached to larger branch circuits.
A window A/C unit would be a room air conditioner and Part VII would apply. Take a look at 440.62.
Chris
Yes I understand 440.60
Yes I understand 440.60
I was reading to deep into 440.55. I am presented with the choice of facts...
1. Article 440 covers AC and Refrigeration equipment.
2. Article 440.55 specifies the use of 15 an 20 Amp branch circuits for use in motor-compressors. ( ever AC and Ref has one )
3. Article 440.62 specifies branch circuit requirements for a room AC.
Now... more facts, defining the conflict.
1. The Room AC was OEM with a 30A cord and GFI plug.
2. The cord and receptacle was replaced with a 20A cord and plug(non-GFI).
3. Is a room AC ever defined as a motor-compressor? ( Not an AC guy... Most of the AC's and Motor-Compressors I've worked on are at large industrial installations. I am guessing that you used FPN at 440.13 to point you to 440.63.)
So....
1. If the branch circuit is rated for 20A, 440.55 doesn't apply, if the motor-compressor is in a room AC. Whereas if said unit was in a fridge it would...
Yes I understand 440.60
I was reading to deep into 440.55. I am presented with the choice of facts...
1. Article 440 covers AC and Refrigeration equipment.
2. Article 440.55 specifies the use of 15 an 20 Amp branch circuits for use in motor-compressors. ( ever AC and Ref has one )
3. Article 440.62 specifies branch circuit requirements for a room AC.
Now... more facts, defining the conflict.
1. The Room AC was OEM with a 30A cord and GFI plug.
2. The cord and receptacle was replaced with a 20A cord and plug(non-GFI).
3. Is a room AC ever defined as a motor-compressor? ( Not an AC guy... Most of the AC's and Motor-Compressors I've worked on are at large industrial installations. I am guessing that you used FPN at 440.13 to point you to 440.63.)
So....
1. If the branch circuit is rated for 20A, 440.55 doesn't apply, if the motor-compressor is in a room AC. Whereas if said unit was in a fridge it would...
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- Location
- Logan, Utah
This is a violation of 110.3(B) plain and simple. If the unit comes with a 30 amp cord with LCDI or AFCI protection you can not change the cord and the cord protection without violating the listing of the product.
A room air-conditioner is considered as an ac appliance. Take a look at the gereral provisions for room air conditioners (440.60)
Chris
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I don't think it is a NEC issue at all.VinceS said:
First off, I don't think the 20A GFCI is going to trip on overcurrent. It only cares about ground faults.
UL is not wrong. You are reading it wrong. The section refers to branch circuits of 15 and 20 Amps. It does not say anything at all about 30A circuits.
I do not think you will get much rock solid guidance on modiifcation of UL listed items. The reason is that there is no law or code that prevents or allows it for this kind of equipment. At worst, the listing would no longer apply, but I see no real downside unless you did something stupid and started a fire.
DanZ
Senior Member
If you modify the A/C (or any UL Listed or CSA? Listed) you remove the UL "approval". I don't think you can actually use the device without UL approval. I could be wrong tho.petersonra said:
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
there is no general legal requirement that anything have a UL listing at all.DanZ said:
- Location
- Logan, Utah
DanZ said:
UL doesn't approve anything, UL lists products. Only the AHJ can approve something.
Chris
weressl
Esteemed Member
petersonra said:
How about equipment listed for hazardous, classified locations? UL being one of the NRTL's.
weressl
Esteemed Member
raider1 said:
UL approves panel shops and electrical equipment repair facilites.
- Location
- Logan, Utah
weressl said:
My point was that UL lists products not approves products, only the AHJ can approve electrical equipment.
Chris
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
weressl said:
there are a few specific ones.
DanZ
Senior Member
That's why I had "approval" in quotes. You lose the listing just didn't sound right for some reason.raider1 said:
On the other hand, I have heard of the AHJ failing hot tub installations because the hot tub didn't have UL listings, or something had been altered.
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sandsnow
Senior Member
- Location
- Southern California
The short answer to the question is "The AHJ"
As an inspector I can approve equipment or my boss can; that has been modified since it left the factory.
UL's take on this is one of hands off. See this link:
http://www.ul.com/regulators/novdec2001.pdf
The listing is not voided or at least UL won't come right out and say that. They will tell you that the product is no longer eligible to bear the listing mark.
I try to look at these things reasonably. If cord cap on your appliance is damaged, then technically you have modified the product by replacing the cord cap. UL has not investigated the use of that cap with the product. We all know that is silly to make a fuss over as long as the cord cap is the right voltage and ampacity.
As an inspector I can approve equipment or my boss can; that has been modified since it left the factory.
UL's take on this is one of hands off. See this link:
http://www.ul.com/regulators/novdec2001.pdf
The listing is not voided or at least UL won't come right out and say that. They will tell you that the product is no longer eligible to bear the listing mark.
I try to look at these things reasonably. If cord cap on your appliance is damaged, then technically you have modified the product by replacing the cord cap. UL has not investigated the use of that cap with the product. We all know that is silly to make a fuss over as long as the cord cap is the right voltage and ampacity.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
sandsnow said:
Does UL list the plug with the appliance or with the cord? Does the UL listing of the appliance even consider what type of plug is on the cord?
Replacing a molded plug on a cord is not the same thing as replacing the cord on the appliance. It is a fact that UL lists replacement attachment plugs. There is a specific UL listing (ELBZ) for power supply cords which says the listing of cordsets does not apply to the appliance.
I believe that to refuse to approve a replacement plug is to refuse to understand the scope of UL's listing procedures and the AHJ's role in approving applications.
sandsnow
Senior Member
- Location
- Southern California
Does UL list the plug with the appliance or with the cord? YES and YES If fit leaves the factory with the power supply cord and attachment plug, then the product is described in the manufacturers procedure as having those characteristics. The manufacturer may be able to substitute the power supply cord with another listed power supply cord of proper rating. That info will also be in their procedure.
Does the UL listing of the appliance even consider what type of plug is on the cord? YES
Replacing a molded plug on a cord is not the same thing as replacing the cord on the appliance. TRUE, but I would look at it the same way. Reasonably.
It is a fact that UL lists replacement attachment plugs. ????? Couldn't find that category. AXUT; AXGV; and RTRT have nothing on replacements. Maybe I missed something.
There is a specific UL listing (ELBZ) for power supply cords which says the listing of cordsets does not apply to the appliance. TRUE, sort of. Actually the listing of the power supply cord does not apply to what is attached to the load end. A cord set and power supply cord are two different things.
I believe that to refuse to approve a replacement plug is to refuse to understand the scope of UL's listing procedures and the AHJ's role in approving applications. AGREED
Does the UL listing of the appliance even consider what type of plug is on the cord? YES
Replacing a molded plug on a cord is not the same thing as replacing the cord on the appliance. TRUE, but I would look at it the same way. Reasonably.
It is a fact that UL lists replacement attachment plugs. ????? Couldn't find that category. AXUT; AXGV; and RTRT have nothing on replacements. Maybe I missed something.
There is a specific UL listing (ELBZ) for power supply cords which says the listing of cordsets does not apply to the appliance. TRUE, sort of. Actually the listing of the power supply cord does not apply to what is attached to the load end. A cord set and power supply cord are two different things.
I believe that to refuse to approve a replacement plug is to refuse to understand the scope of UL's listing procedures and the AHJ's role in approving applications. AGREED
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- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
sandsnow said:
If the UL listing for a power supply cord does not apply to what is attached to the load side of the cord, then why would changing the line side of the cord affect the listing of the load side device?
As for a plug that can be used as a replacement on a flexible cord, it should be listed as an Attachment Plug (AXGV) under UL 498. A cordset has connectors on both ends (i.e. an extension cord) while a power supply cord has no connector on its load end. But both are allowed to have Attachment Plugs on their line ends (a molded-on connector is not an attachment plug).
sandsnow
Senior Member
- Location
- Southern California
jim dungar said:
All I can tell you is what I've learned from UL over the years. If the product leaves the factory with a certain part then changing that part will affect the integrity of the listing. While it silly to think that replacing a 30 amp plug with a 30 amp plug would make the product any less safe, what I have stated is how UL views the scenario. The exception would be field replaceable parts identified in the product instructions.
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