Hydro tub

[marc deschenes]

Re: Hydro tub

I'll ask again , does this mean you can wire a 50 amp single receptacle on an individual branch circuit rated at 15 amps and comply with the N.E.C. ? yes or no .

 

[pierre]

Re: Hydro tub

In answer to your last post, the answer is yes. The NEC concerns itself with safety - if one installs a 50 ampere rated receptacle on a 15 ampere rated branch circuit and tries to use a 50 amp load, the circuit breaker will open...just what the NEC wants to happen.

Bad for the installer/consumer, but safe never the less.
Like I mentioned, a poor design, and if it really did happen, it would not be a real electrician who installed it anyway... I hope

 

[marc deschenes]

Re: Hydro tub

I would never do this . It seems odd to me that the N.E.C. would allow for a design that will almost certainly result in an overload of the branch circuit , I'm not so sure I would choose the word safe to describe an individual branch circuit rated at 15 amps supplying a device rated at 50 amps. The safest circuit is the one that never sees an overload,... this one probably would.

 

[jimwalker]

Re: Hydro tub

Could we install a 50 cord and plug on a 20 amp piece of equipment or a perhaps a lamp ?Thinking no because then that lamp could be pluged into a range outlet.

[ August 28, 2005, 05:05 PM: Message edited by: jimwalker ]

 

[augie47]

Re: Hydro tub

will almost certainly result in an overload of the branch circuit

what?
The outlet will overload the circuit ? I think not.
The circuit is protected by the OCPD.
Althiugh its not necessarily a design I approve of, I have had commercial/industrial accounts request 50 amp or so recepts on circuits of lesser ampacity to get the "beef" (life) fromn the heavier duty outlet. (High usage recept)

 

[peter d]

Re: Hydro tub

Originally posted by marc deschenes:
It seems odd to me that the N.E.C. would allow for a design that will almost certainly result in an overload of the branch circuit ,

The NEC allows it because it's perfectly safe. As Pierre summed up so nicely, a 50 amp load placed on a 15 amp OCPD is going to open that OCPD in a very short amount of time.

 

[marc deschenes]

Re: Hydro tub

Relying on the ocpd is not a wise thing to do .They do not always work the way they are intended ,sometimes they explode.

What about 406.7 I see it address the 20 amp T slot receptacle .It also states "Receptacles.... shall be constructed such that the receptacle or cord connectors do not accept an attachment plug with a different voltage or current rating from that for which the device is intended". But we are saying that we can feed it with a circuit of a different rating than that for which the device is intended.
So , and I don't mean to sound like a jerk , we can take a 50 amp 250 volt rated receptacle and run a 15 amp 125 volt individual branch circuit to it and the N.E.C. is good with that ? This is blowing my mind and I must say this forum is good for our trade!

 

[iwire]

Re: Hydro tub

Marc how is this any different than a typical multi outlet branch circuit?

If I have five - 15 amp duplex receptacles on a 15 amp circuit the OCP could very easily be overloaded.

 

[peter d]

Re: Hydro tub

Originally posted by marc deschenes:
[This is blowing my mind and I must say this forum is good for our trade!

This forum has destroyed many incorrect beliefs that many of us have held for a long time. I can't even tell you how much I have learned in just the 2-3 years I have been active here. Much of that learning has been discarding things I have heard from misinformed electricians and replacing it with information solidly based on the NEC and electrical theory.

 

[marc deschenes]

Re: Hydro tub

Well for starters it is an individual branch circuit which by definition serves one piece utilization equipment. I can't imagine U.L. approves too many pieces of equipment that have a 15 amp rating with a 50 amp attachment plug. As for field installation ,most agree this is a s#itty design . How was your branch circuit calculated is it a general lighting , What kind of load are you serving? there are all kinds of codes that limit what is an acceptable load ,My point is the N.E.C. tries to avoid over loads .This design invites one . How you ask? by feeding a device listed and rated for 50 amps that will accept an attachment plug also listed and rated for 50 amps with a 15 amp circuit.
210.23 States" in no case shall the load exceed the branch circuit ampere rating , An Individual branch circuit shall be permitted to supply any load for which it is rated...."

This branch circuit is rated at 15 amps the device will accept a load in excess of that , This in my mind constitutes a case where the load is able to exceed the branch circuit rating. I may not have it exactly right , I'm just an average joe with a high school education . It does say in no case.
What is the point of configuring plugs and receptacles if not to prevent this ?

 

[iwire]

Re: Hydro tub

Originally posted by marc deschenes:
My point is the N.E.C. tries to avoid over loads

Not always, check out 230.90 Exception No. 3.

But that is obscure, something much more common is any multi receptacle circuit.

Any multi receptacle circuit can be easily overloaded regardless of the plug configuration.

Originally posted by marc deschenes:
210.23 States" in no case shall the load exceed the branch circuit ampere rating , An Individual branch circuit shall be permitted to supply any load for which it is rated...."

Exactly, An Individual branch circuit shall be permitted to supply any load for which it is rated

The receptacle is not the load, the utilization equipment is the load.

Originally posted by marc deschenes:
This branch circuit is rated at 15 amps the device will accept a load in excess of that , This in my mind constitutes a case where the load is able to exceed the branch circuit rating.

Yes the load could exceed the OCP just like the load on a multi receptacle circuit can exceed the OCP.

If we say that a 30 amp receptacle fed with a 15 amp OCP is dangerous than we would also have to say a multi outlet circuit is also dangerous as it too can be overloaded.

The only answer to that would be individual branch circuits to every receptacle.

I will leave you with this

90.1 Purpose.
(B) Adequacy. This Code contains provisions that are considered necessary for safety. Compliance therewith and proper maintenance will result in an installation that is essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use.

The code is for safety not convenience.

[ August 29, 2005, 05:02 AM: Message edited by: iwire ]

 

[pierre]

Re: Hydro tub

From Peter D

"This forum has destroyed many incorrect beliefs that many of us have held for a long time. I can't even tell you how much I have learned in just the 2-3 years I have been active here. Much of that learning has been discarding things I have heard from misinformed electricians and replacing it with information solidly based on the NEC and electrical theory."

I wholeheartily agree!!!

Marc
I hope you do not think that we are advocating this type of installation, just that it is not a violation as written.

Your reference
"406.7 Noninterchangeability. Receptacles, cord connectors, and attachment plugs shall be constructed so that receptacle or cord connectors do not accept an attachment
plug with a different voltage or current rating from that for which the device is intended. However, a 20-ampere T-slot receptacle or cord connector shall be permitted to accept a
15-ampere attachment plug of the same voltage rating. Non?grounding-type receptacles and connectors shall not accept grounding-type attachment plugs."

It does not mention branch circuit, but the device.

Again as Bob and others have pointed out, the NEC is not perfect, and it is not a design manual.

Good sense and good judgement and experience will help with the design aspect of any installation.

 

[marc deschenes]

Re: Hydro tub

I understand , I 'm not sure why we have all these different configurations if we can supply the device with a voltage / amperage of a rating different than what the device is listed labeled and configured for.

So if you read on the front of the device 50 amp 250 volt ,It can really be 15 amp 125 volt . This seems to go against what I was taught about the labeling of devices and equipment.
I guess the device is still listed for the 50 amp 250 volt , but the label is all wrong , I'm just surprised we can supply this with a voltage and amperage that is different than the lable on the device. Sould we not at least have to change the label?

Thanks for the replies , thanks for making me think.

 

[hurk27]

Re: Hydro tub

I'll make it simple:

This is a single 15 amp 125 volt receptacle, it can only be installed on a circuit not rated over 15 amps unless there is more than one installed on the same circuit 210.21(B)(1)


Edited again because I had the last one wrong.

[ August 30, 2005, 08:50 PM: Message edited by: hurk27 ]

 

[JohnE]

Re: Hydro tub

Wayne,

Your ground should be facing down.

 

[jimwalker]

Re: Hydro tub

Can i see this in white as i don't care for ivory

 

[hurk27]

Re: Hydro tub

Wayne,

Your ground should be facing down.

In my world the ground faces up and the sky faces down.

Can i see this in white as i don't care for ivory

Sure just go to: Leviton

 

[LarryFine]

Re: Hydro tub

Originally posted by hurk27:

This is a single 20 amp 125 volt receptacle, it can be installed on either a 15 or 20 amp circuit and will accept either a 15 or 20 amp plug. 210.21(B)(3)

I have to disagree with this one. I believe that this receptacle must be installed on only a 20-amp circuit. The slot shape indicates that this circuit is capable of providing the currcnt necessary for a load equipped with a 20-amp plug.

Remember, receptacles are configured as rejection devices, similar to panels that accept the quantity of tandem breakers that will not exceed the circuit-quantity limit. A 15-amp receptacle rejects 20-amp plugs.

 

[macmikeman]

Re: Hydro tub

This is a single 20 amp 125 volt receptacle, it can be installed on either a 15 or 20 amp circuit and will accept either a 15 or 20 amp plug. 210.21(B)(3

I am not in agreement with Larry Fine on this, It is a code violation to put this particular single receptacle on a 15 amp circuit, if it is the only outlet in the circuit. However if it shares the circuit with other 15 amp receptacles it meets code to use it.

Put in a duplex 15 amp receptacle and forget about it[ /QUOTE]
I would add to this - put in a 15 amp gfi receptacle and forget about it, since it is a hydromassage tub in the original post.

 

[jimwalker]

Re: Hydro tub

"I would add to this - put in a 15 amp gfi receptacle and forget about it, since it is a hydromassage tub in the original post. "

no can do.It said dedicated and a duplex gfci is 2 receptacles.It will work but does not meet the specs