Dedicated Circuits for Kitchen Appliances

[jeff48356]

Just wondering about required (or recommended) ampacities for dedicated kitchen appliance circuits.

I realize that the overhead microwave oven should be powered by a dedicated 20-amp circuit (which includes the 120V gas range outlet below), and 15A for the garbage disposal. But what about the dishwasher and refrigerator, if these are each to be wired to a dedicated circuit. Would 15A be sufficient? Or would these also need to be 20A?

Also, for an electric range, would 40A on 8-3 copper Romex suffice? Or would 50A using 6-3 be better?

 

[jumper]

Just wondering about required (or recommended) ampacities for dedicated kitchen appliance circuits.

I realize that the overhead microwave oven should be powered by a dedicated 20-amp circuit (which includes the 120V gas range outlet below), and 15A for the garbage disposal. But what about the dishwasher and refrigerator, if these are each to be wired to a dedicated circuit. Would 15A be sufficient? Or would these also need to be 20A?

Also, for an electric range, would 40A on 8-3 copper Romex suffice? Or would 50A using 6-3 be better?

If the overhead micro is a cord connected range hood combo unit, the 120V gas range receptacle cannot be on that circuit, you may put it on a SABC however. Manufactures instructions will decide if a 15A or 20A is needed is needed for the micro.

The refrigerator may be on a SABC or a individual/dedicated circuit of 15A or greater.

Instructions will also tell the required sizes needed the other appliances. You may guess if you wish, I do not myself.

 

[growler]

Just wondering about required (or recommended) ampacities for dedicated kitchen appliance circuits.

Required is one thing and good design is another.

If given the chance and the customer is willing to pay I will add more circuits to a kitchen than required. If the customer only wants code minimum and they have problems later it's not my concern.

 

[jeff48356]

If the overhead micro is a cord connected range hood combo unit, the 120V gas range receptacle cannot be on that circuit, you may put it on a SABC however. Manufactures instructions will decide if a 15A or 20A is needed is needed for the micro.

The local inspector said that the gas range outlet CAN be on the same circuit as the over-the-range microwave oven, and that's how I have been wiring them recently. 20-amp circuit, of course.

 

[jumper]

The local inspector said that the gas range outlet CAN be on the same circuit as the over-the-range microwave oven, and that's how I have been wiring them recently. 20-amp circuit, of course.

Is it a cord connected combo range hood and micro unit?

 

[JFletcher]

Just wondering about required (or recommended) ampacities for dedicated kitchen appliance circuits.

I realize that the overhead microwave oven should be powered by a dedicated 20-amp circuit (which includes the 120V gas range outlet below), and 15A for the garbage disposal. But what about the dishwasher and refrigerator, if these are each to be wired to a dedicated circuit. Would 15A be sufficient? Or would these also need to be 20A?

Also, for an electric range, would 40A on 8-3 copper Romex suffice? Or would 50A using 6-3 be better?

There was a thread here last week about an HD employee telling customers that 40A to a range is sufficient. I guess HD doesnt sell these:

http://www.ajmadison.com/cgi-bin/aj...J-f092FkSQnLtWDUAc7kMOlUjcoeWUA9IFRoCf_nw_wcB

Power Requirements: 240V/208V/60Hz/50A

Typically (not always) ranges wind up near panels, so the extra cost of 6/3 over 8/3 is minimal. I'd personally rather eat the few dollars than have to rerun that cable ever.

 

[growler]

There was a thread here last week about an HD employee telling customers that 40A to a range is sufficient. I guess HD doesnt sell these:

http://www.ajmadison.com/cgi-bin/aj...J-f092FkSQnLtWDUAc7kMOlUjcoeWUA9IFRoCf_nw_wcB

Power Requirements: 240V/208V/60Hz/50A

Typically (not always) ranges wind up near panels, so the extra cost of 6/3 over 8/3 is minimal. I'd personally rather eat the few dollars than have to rerun that cable ever.

I used to run 50 amp range circuits but these days if there is no range or model number for range to be used on the job and the only thing known is that a range is to be installed they get 8/3 and a 40 amp breaker. I have not returned any cable.

 

[Greg1707]

The local inspector said that the gas range outlet CAN be on the same circuit as the over-the-range microwave oven, and that's how I have been wiring them recently. 20-amp circuit, of course.

I believe this should be a suggested change to the code. It is very convenient to supply the gas range and the over the range microwave on the same circuit. There is no load issues with this setup.

 

[Smart $]

I believe this should be a suggested change to the code. It is very convenient to supply the gas range and the over the range microwave on the same circuit. There is no load issues with this setup.

Here's the rub...

210.23(A)...

(2) Utilization Equipment Fastened in Place. The total
rating of utilization equipment fastened in place, other than
luminaires, shall not exceed 50 percent of the branch circuit
ampere rating where lighting units, cord-and-plug-connected
utilization equipment not fastened in place, or
both, are also supplied.

So what is the nameplate rating of the micro-hood combo? More than likely over 50% on a 15A circuit... automatically borderline on a 20A circuit.

I don't see the CMP changing a thing since there is already a stipulation in place.

 

[Greg1707]

sabc

sabc

Here's the rub...

210.23(A)...

So what is the nameplate rating of the micro-hood combo? More than likely over 50% on a 15A circuit... automatically borderline on a 20A circuit.

I don't see the CMP changing a thing since there is already a stipulation in place.

I understand. But what is the difference of installing the gas range on the SABC when the fridge is on that circuit?

 

[Smart $]

I understand. But what is the difference of installing the gas range on the SABC when the fridge is on that circuit?

It's a matter of having some power "reserved" for not-fixed-in-place, cord-and-plug-connected equipment. Most refrigerators do not draw anywhere near 10A, so there should be "reserved" power on a 20A SABC for other equipment.

Technically, a gas range does not have to be on an SABC.

 

[goldstar]

Here's the rub...

210.23(A)...

(2) Utilization Equipment Fastened in Place. The total
rating of utilization equipment fastened in place, other than
luminaires, shall not exceed 50 percent of the branch circuit
ampere rating where lighting units, cord-and-plug-connected
utilization equipment not fastened in place, or
both, are also supplied.

So what is the nameplate rating of the micro-hood combo? More than likely over 50% on a 15A circuit... automatically borderline on a 20A circuit.

I don't see the CMP changing a thing since there is already a stipulation in place.

I've found that most times you can't get the info on the microwave unit at the time of installation. We all just automatically install a 20 amp circuit to play safe. In randomly looking at the specs on a GE microwave unit I found no required amperage info in the on-line ads. I went further and found the installation booklet and it showed this :

Observe all governing codes and ordinances.
(That's pretty much a CYA type of thing for the manufacturer)

Required:
■ A 120 volt, 60 Hz, AC only, 15- or 20-amp electrical supply
with a fuse or circuit breaker.

Recommended:
■ A time-delay fuse or time-delay circuit breaker.
■ A separate circuit serving only this microwave oven

Notice the part that indicates "recommended". So, aside from what the Code specifically states, in all fairness how much can a 25 watt oven bulb and a gas range igniter draw and will it fit (along with the microwave unit) within the 50% branch circuit rating ? IMHO, I think a future CMP should consider making a change just for situations like this. However, if you're a betting person I'm sure it's a shot in a thousand.:happyyes:

 

[Smart $]

I've found that most times you can't get the info on the microwave unit at the time of installation. We all just automatically install a 20 amp circuit to play safe. In randomly looking at the specs on a GE microwave unit I found no required amperage info in the on-line ads. ...

I had no problem. Go here...

http://products.geappliances.com/appliance/gea-specs/JVM3160RFSS

...click on "SPECS & DETAILS"...

In the interest of saving time, it says 15A, 1580W.

On the other hand, if the draw is so low, there's no problem putting it on the SABC in the vicinity, right?

All in all, I'm not saying the Code is without error on a lot of things. The hard part is getting the CMP members to "listen".

 

[flatlander]

Almost everyone these days has a micro.
If it sits on the counter no dedicated outlet.
If is attached to the wall or cabinet it will probably require a dedicated outlet. (no other outlets)

We just need to live with it.

 

[George Stolz]

I don't see the CMP changing a thing since there is already a stipulation in place.

Indeed; they don't need to make it explicit because it is already permitted. The gas range and the microwave can share a circuit as fixed appliances as long as their combined load does not exceed 100% of the branch circuit rating. 210.23(A) doesn't factor in at all, because there are no general purpose receptacle outlets on this circuit anyway.

 

[jumper]

Yes, a micro and a gas range rec can share a circuit, but not if the micro is a cord connected range hood combo unit.

OP never clarified when I asked.

 

[Smart $]

Indeed; they don't need to make it explicit because it is already permitted. The gas range and the microwave can share a circuit as fixed appliances as long as their combined load does not exceed 100% of the branch circuit rating. 210.23(A) doesn't factor in at all, because there are no general purpose receptacle outlets on this circuit anyway.

But a typical gas range is not a fixed appliance.

 

[Smart $]

Yes, a micro and a gas range rec can share a circuit, but not if the micro is a cord connected range hood combo unit.

OP never clarified when I asked.

Why?

 

[curt swartz]

Why?

2011 NEC
422.16(B)(4)(4)

 

[jumper]

:happyyes:

2011 NEC
422.16(B)(4)(4)