wire guage

Yes.

Yes. Derating of the neutral is unacceptable unless your doing feeders and services.

Depends on the breaker rating, type of insulation, configuration (open air, conduit,, etc.). In the USA see the tables in Article 310 of the National Electrical Code. #10 can be used with circuit breakers rated for 30A (60C wire) to 40A (90C wire). Neutral and ungrounded need to be at least the size/type indicated for the circuit breaker rating. Also, do not install recepticles, etc. rated for 15A on a circuit protected with a circuit breaker of higher rating. Bill Kaszeta Photovoltaic Resources Int'l Tempe Arizona USA snipped-for-privacy@pvri-removethis.biz

Sure, It carries the same current as the hot.

"Bill Kaszeta / Photovoltaic Resources" wrote in message news: snipped-for-privacy@news.east.earthlink.net...

It is ok to put 15A receptacles on a 20A circuit. Perfectly safe, and meets code.

Ben Miller

Thanks for all the great information...it actually made me think of another question. Is it possible to put 27 (100W or lower bulbs) lights on this 30A breaker or would it be safer to split it into 2 or 3 seperate 15A breakers. I wonder this because of the comment about putting 15A receptacles on this breaker?

The above statement does not apper correct. Other than for motors, motor-compressors, and maybe some other uncommon circuits AWG No. 10 copper cannot be installed on a 40 ampere breaker per 240.4(D). The No. 10 with a 90 degree C insulation can be used where derating is done with the 90 degree C. ampacity but the conductor can not be used on a breaker greater than the 30 amperes. Also, AWG No. 10 aluminum is limited to a 25 ampere breaker per 240.4(D).

(Try my Table 310.16 calculator at

it just took 10 weeks to get it right.)

A 15 or 20 ampere rated multi receptacle that includes the common duplex can be installed on a 15 or 20 ampere rated circuit per Table

210.24. However, a single individual receptacle on an individual branch circuit must be rated at least the same as the circuit per 210.21(B)(1).

I stand to be corrected. A 20 ampere receptacle cannot be installed on a 15 ampere circuit per Table 210.21(B)(3). A 15 ampere maximum receptacle is all that is allowed. I don't recall this being in some earlier editions of the Code. However, a 15 or 20 ampere receptacle can be installed on a 20 ampere branch circuit other than an indiviual branch circuit.

Yes.

-- Ferme le Bush

That should not be a problem except that the inrush current may be many times 30A. I can conceive of situations where that might trip a breaker or not allow full voltage to develop.

-- Ferme le Bush

The NEC doesn't permit lights on 30A ckts for residential. For non-residential "fixed lighting units with heavy duty lampholders" can be on 30A ckts. For residential you need 2 15 or 20A ckts. Likely a good idea in non-residential too.

bud--

I believe it is a long term requirement. It doesn't make sense to allow a 20A device on a 15A circuit.

But from your first post, if you have only one outlet on a 15A circuit it can be 20A, or 30A, 100A.... A strange rule.

bud--

NEC table 210.24 spells this all out...

15A receptacle on 15A circuit 15 or 20 A receptacle on 20A circuit 30A receptacle on 30A circuit 40A receptacle on 40A circuit 50A receptacle on 50A circuit

The circuit rating ids the OCPD rating. You can't put the smaller devices on the higher rated circuits, as the utilization equipment and cords would not be protected adequately by the OCPD. You can't put the larger devices on the lower rated circuits, because that would obviously allow equipment to overload the circuit and trip the OCPD.

For lighting, only 15 or 20 A circuits are allowed in a residence. You can go higher in non-residential applications with heavy duty lampholders.

Ben Miller

One correction... you can use 40A or 50A receptacles on a 40A circuit.

Ben Miller

Entirely reasonable. But 210.24 applies to 2 or more receptacles on a circuit as does 210.21-B-3. Single receptacles on a circuit are covered by 210.21-B-1: "rating not less than the branch circuit". About 1/2 year ago someone figured out that section allows a 100A receptacle on a

15A circuit - "a strange rule". (Not that anyone with any brains would do that.)

bud--

Yes indeed. Even the handbook explains it as "For example, a single receptacle on a 20-ampere circuit must be rated at 20 amperes;...". Hopefully common sense prevails in some cases!

Ben Miller

I agree with everything except that last statement. If the circuit is dedicated for one outlet (such as refrigerator or disposal or some such), then yes the receptacle must also be rated for the same current as the breaker. But if there are several receptacles such as a typical branch circuit, it is acceptable to put 15A receptacles on a 20A circuit. The NEC allows this as it assumes you can't plug an appliance rated for more than

15A into a 15A receptacle (you can't because the plug design would be different), and the circuit could have several loads that are < 15A that add up to > 15A.

daestrom

Gentlemen, "if I were the owner of the establishment or house, I want the 30 A rated receptacle( if there is any available ) for my 20 A ckt, the price will not be significant for a single house (for many houses like a condominium, the difference is substantial, a differnt case ) for the reason that it is much durable ( not easily heated by a temporary excess current ) than a lower rated 20 A, it is my right to load my property as I see fit, that is why I paid for a 20 A circuit brkr that is suppose to trip if it a sustained over 20A current passes to it. I will not accept the NEC limiting me on this."

For the case of a big savings when using a a smaller receptacle rating, "I will put a 10A or 15A receptacles on a 20 A circuit for the reason that high load appliances are seldom used and that there are many receptacles to plug on,the chance of over loading an outlet is remote, also a failure of a receptacle in case of overload (i.e short circuiting the wires bcoz of melting of insulating barrier at terminals or near the wires) will again trip the breaker due to instantaneous overcurrent there by stoping further burning.. Again that is why a "cb" is used, whats the purpose of thousnds of men,countles hours spent in developing this thing. Again there is another "Main cb" that will I had to buy."( this idea is dangerous if not consistent with the fire rating of the house materials used. As insurance will not cover accidents caused by violaton of the Code. As practioners we must not conceed the compliance of the with our clients " economic philosopy " as fires are caused by a violent spark on (gas)LPG leaked locations or near combustible materials like curtains.)

high contact resistance when a loose connection occurs between plug & receptacle,( I suggest UL listed and genuine products should be used, & stop using those cheap asian things) which the responsibilty of the user, I think that education has a role here.

Also if can be supplied by a utility company,apply for a 220 or 230 line to neutral service for branch circuits , or for three phase 400 /

230v for service of large occupancies. This is to take advantage of the 600v ratings of the wires, & majority of the materials used.

Gentlemen, "if I were the owner of the establishment or house, I want the 30 A rated receptacle( if there is any available ) for my 20 A ckt, the price will not be significant for a single house (for many houses like a condominium, the difference is substantial, a differnt case ) for the reason that it is much durable ( not easily heated by a temporary excess current ) than a lower rated 20 A, it is my right to load my property as I see fit, that is why I paid for a 20 A circuit brkr that is suppose to trip if it a sustained over 20A current passes to it. I will not accept the NEC limiting me on this."

For the case of a big savings when using a a smaller receptacle rating, "I will put a 10A or 15A receptacles on a 20 A circuit for the reason that high load appliances are seldom used and that there are many receptacles to plug on,the chance of over loading an outlet is remote, also a failure of a receptacle in case of overload (i.e short circuiting the wires bcoz of melting of insulating barrier at terminals or near the wires) will again trip the breaker due to instantaneous overcurrent there by stoping further burning.. Again that is why a "cb" is used, whats the purpose of thousnds of men,countles hours spent in developing this thing. Again there is another "Main cb" that will I had to buy."( this idea is dangerous if not consistent with the fire rating of the house materials used. As insurance will not cover accidents caused by violaton of the Code. As practioners we must not conceed the compliance of the with our clients " economic philosopy " as fires are caused by a violent spark on (gas)LPG leaked locations or near combustible materials like curtains.)

high contact resistance when a loose connection occurs between plug & receptacle,( I suggest UL listed and genuine products should be used, & stop using those cheap asian things) which the responsibilty of the user, I think that education has a role here.

Also if can be supplied by a utility company,apply for a 220 or 230 line to neutral service for branch circuits , or for three phase 400 /

230v for service of large occupancies. This is to take advantage of the 600v ratings of the wires, & majority of the materials used.