Can (3) 6-20r 20 amp 208v Duplex Receptacles be on a 60 amp circuit?

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hbiss said:
Any time I see a duplex receptacle I consider it to be for general use. Especially when they are all over the place.

Maybe for a lot of European equipment. :)

-Hal
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6-20 is 20 amp 250volts. When he says not general use I think he mostly means it isn't 5-15 or 5-20. Some places 16-20 (20 amp 480 volts) is sort of general use to some extent, but not like 5-15 and 5-20 are to almost everyone.
 
The NEC recognizes equipment that meets testing requirements by OSHA designated Nationally Recognized Testing Laboratories (NRTL).

Any cord & plug must be listed by an accepted NRTL, such as ETL or UL. Improper listings void claims, and are not insurable.

If cord design fails NEC requirements for overload or short-circuit protection, passing NRTL requirement are not possible.

NRTL label should be on cord itself, on packaging, and vendors product description, or user manual.

Close up image of NRTL label will help me determine if listing is counterfeit. Counterfeit listings for electrical equipment are common.
 
ramsy said:
The NEC recognizes equipment that meets testing requirements by OSHA designated Nationally Recognized Testing Laboratories (NRTL).

Any cord & plug must be listed by an accepted NRTL, such as ETL or UL. Improper listings void claims, and are not insurable.

If cord design fails NEC requirements for overload or short-circuit protection, passing NRTL requirement are not possible.

NRTL label should be on cord itself, on packaging, and vendors product description, or user manual.

Close up image of NRTL label will help me determine if listing is counterfeit. Counterfeit listings for electrical equipment are common.
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I am nearly certain that the 6-50p and each of the (8) c13 cords will be stamped with a rating on the cord/plug (the C13 will have a 15amp rating on the cord). However, these ratings are for such isolated parts of the setup. That entire setup will not have an "all encompassing" rating, just a rating for each of the parts.
 
A closeup of that power tap would help, but it looks like a bunch of cables joined in a 4 square box with some nm clamps. I bet it has no NRTL listing and would not pass if tested.

Not that the concept is necessary flawed; 'spider boxes' are well known job site tools, if you provide suitable OCPD at the point where the 12ga cords branch off.

Jon
 
winnie said:
A closeup of that power tap would help, but it looks like a bunch of cables joined in a 4 square box with some nm clamps. I bet it has no NRTL listing and would not pass if tested.

Not that the concept is necessary flawed; 'spider boxes' are well known job site tools, if you provide suitable OCPD at the point where the 12ga cords branch off.

Jon
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Thanks! These are custom made so it is doubtful a rating is attached. When you mention the OCPD, do you mean an OPCD for each of the eight leads?
 
cottora said:
Thanks! These are custom made so it is doubtful a rating is attached. When you mention the OCPD, do you mean an OPCD for each of the eight leads?
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Yes, the entire assembly must be tested & listed, since any point can fail, and ignite the building.

Also, if your load calc is under estimated, your only indication is smoke & burn.

Construction site spider boxes have larger junction boxes to accommodate proper sized OCPD for each minor branch.
 
cottora said:
This is an off the shelve Power Distribution solution for our business. Here is the thing, this is essentially creating a tap. This 50AMP 6-50 gets split into eight c13 cords. But the C13 cables are not rated for 50AMP (they are 12AWG). That being said, the C13 will never draw more than 15 amps (unless shorted). Does NEC "stop" at the receptacle as I can't image this being allowed to be hardwired? Thanks

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NEC does stop at the receptacle, to an extent. Question is whether your power distribution assembly you have there is listed and for the purpose, if not it will likely be deemed as a substitute for what should have been premises wiring even though it is beyond the last receptale of the actual premises wiring.

Sort of no different than putting several receptacles adjacent to the service equipment then running portable extension cords throughout the premises to power items that should have had a real branch circuit run to their locations.
 
I'm not so sure the NEC stops at the wall receptacle. I've been spending the last few months, and probably the next year, assessing anything that "plugs in" for NRTL compliance. For things that are not NRTL listed, we can hire a field evaluation body to bless it, or we have some employees that have been designated as allowed to bless the item. This involves some NEC basics (guarding, grounding), and verifying the bonding of exposed metal with a bonding meter. This is being pushed by OSHA and has actually been a Washington State rule for quite some time. It is just difficult to enforce, as the electrical inspector is the only one who typically looks at utilization equipment, and cord-and-plug things are usually not there when the inspector shows up.
 
cottora said:
This is an off the shelve Power Distribution solution for our business. Here is the thing, this is essentially creating a tap. This 50AMP 6-50 gets split into eight c13 cords. But the C13 cables are not rated for 50AMP (they are 12AWG). That being said, the C13 will never draw more than 15 amps (unless shorted). Does NEC "stop" at the receptacle as I can't image this being allowed to be hardwired? Thanks

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I found the ebay listing for these. It looks really shoddy -4S box with multiple cords going into NM cable clamps. Have a fire with one present and good luck getting the ins co to pay.....
 
Would one of these make any more sense? https://www.tripplite.com/5-5.8kw-s...24-c13-l6-30p-10ft-cord-0u-vertical~PDUMV30HV
This one uses an L6-30 plug and costs around $240, or you can get them in L6-20 for about $75 less but will be installing more receptacles. I like these because of the ammeter on the front. Server type PDUs have these IEC type outlets, but getting short C13/C14 cords is easy. IT loads are difficult to predict unless you've metered one of these mining machine while its doing its business. Getting that load wrong many times has you putting in more power than needed which means more cooling than needed.
 
Todd0x1 said:
I found the ebay listing for these. It looks really shoddy -4S box with multiple cords going into NM cable clamps. Have a fire with one present and good luck getting the ins co to pay.....
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I believe that you are correct. That said, from a practical standpoint, there is nothing that can burn but the cord.
 
suemarkp said:
Would one of these make any more sense? https://www.tripplite.com/5-5.8kw-s...24-c13-l6-30p-10ft-cord-0u-vertical~PDUMV30HV
This one uses an L6-30 plug and costs around $240, or you can get them in L6-20 for about $75 less but will be installing more receptacles. I like these because of the ammeter on the front. Server type PDUs have these IEC type outlets, but getting short C13/C14 cords is easy. IT loads are difficult to predict unless you've metered one of these mining machine while its doing its business. Getting that load wrong many times has you putting in more power than needed which means more cooling than needed.
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Those would be ideal. However, that unit can handle 4 miners so deploying them would cost $48,000. The units offer power fallback and monitoring.
 
suemarkp said:
I'm not so sure the NEC stops at the wall receptacle. I've been spending the last few months, and probably the next year, assessing anything that "plugs in" for NRTL compliance. For things that are not NRTL listed, we can hire a field evaluation body to bless it, or we have some employees that have been designated as allowed to bless the item. This involves some NEC basics (guarding, grounding), and verifying the bonding of exposed metal with a bonding meter. This is being pushed by OSHA and has actually been a Washington State rule for quite some time. It is just difficult to enforce, as the electrical inspector is the only one who typically looks at utilization equipment, and cord-and-plug things are usually not there when the inspector shows up.
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It kind of does yet kind of doesn't. If what is plugged in isn't the utilization equipment being served it generally needs to be listed for whatever purpose it is serving.

Like I said before you can't put several receptacles next to your service panel and then run extension cords to all your utilization equipment not in that vicinity, temporary purposes would be an exception.
 
cottora said:
Those would be ideal. However, that unit can handle 4 miners so deploying them would cost $48,000. The units offer power fallback and monitoring.
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What is the power inlet plug on these miners C13 or C19? There are other PDUs that use larger plugs (typically up to 60A but those are expensive pin and sleeve type), and horizontal ones that take up less space. What seems different for you is your miner machines need a lot of power. Many servers only draw a few amps and have redundant power supplies (cutting power in half per supply until one fails), so a stack of them may need 30 C13's while the total load is around 30 amps. You may be on the cheapest path if each individual machine draws over 5 amps. It comes down to cost per outlet and whether PDUs save you anything over panelboard space, circuit breaker, cable runs, and the make up of each box.
 
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