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#1
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electrical questions - cooktop and oven
I'm replacing my range with a separate cooktop and oven. The range is
on a 60 amp 240V circuit. The new appliances have the following electrical requirements: Oven: 30 Ampere, 208/240 Volts. Cooktop: 40 Ampere, 208/240 Volts. Also the manufacturer recommends a time-delay fuse or circuit breaker and a separate circuit for each. Can I use the existing 60 amp circuit for both? If I need to get two circuits in there, can they share the same neutral? Both appliances will be connected wire-to-wire (no plugs). Can I use the same box for both of them? Thanks, Matt P.S. I'm getting conflicting answers and a wide range of quotes from electricians, so I wanted to get a better idea. |
#2
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electrical questions - cooktop and oven
wrote in message The new appliances have the following electrical requirements: Oven: 30 Ampere, 208/240 Volts. Cooktop: 40 Ampere, 208/240 Volts. Also the manufacturer recommends a time-delay fuse or circuit breaker and a separate circuit for each. Can I use the existing 60 amp circuit for both? What you can (or maybe lucky to get always with) and what you should do for ultimate safety, are different things. The manufacturer has a reason for the requirements. I sure as hell won't tell you to try it knowing the recommendations are different. |
#3
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electrical questions - cooktop and oven
wrote in message oups.com... I'm replacing my range with a separate cooktop and oven. The range is on a 60 amp 240V circuit. The new appliances have the following electrical requirements: Oven: 30 Ampere, 208/240 Volts. Cooktop: 40 Ampere, 208/240 Volts. Also the manufacturer recommends a time-delay fuse or circuit breaker and a separate circuit for each. Can I use the existing 60 amp circuit for both? I would not. If I need to get two circuits in there, can they share the same neutral? I would not do it that way/ Both appliances will be connected wire-to-wire (no plugs). Can I use the same box for both of them? Thanks, Matt P.S. I'm getting conflicting answers and a wide range of quotes from electricians, so I wanted to get a better idea. |
#4
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electrical questions - cooktop and oven
You can do anything you want (unless it's getting inspected), because it's
your house, and very few people will care if you burn it down. What you are SUPPOSED to do, is install one 30amp breaker and one 40amp breaker. Then run two separate lines to each appliance. It's ok to use the existing wire for one of the circuits. You can probably use the same box for both wires, but every box has a maximum capacity, mostly for heat build up purposes. wrote in message oups.com... I'm replacing my range with a separate cooktop and oven. The range is on a 60 amp 240V circuit. The new appliances have the following electrical requirements: Oven: 30 Ampere, 208/240 Volts. Cooktop: 40 Ampere, 208/240 Volts. Also the manufacturer recommends a time-delay fuse or circuit breaker and a separate circuit for each. Can I use the existing 60 amp circuit for both? If I need to get two circuits in there, can they share the same neutral? Both appliances will be connected wire-to-wire (no plugs). Can I use the same box for both of them? Thanks, Matt P.S. I'm getting conflicting answers and a wide range of quotes from electricians, so I wanted to get a better idea. |
#6
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electrical questions - cooktop and oven
My suggestion: leave the existing 60 amp wire and box, change its breaker to 40 amps, and use it for the 40 amp load. For the other load, run a separate, new, 30 amp line with a new box. Cheers, Wayne Thanks Wayne. That's what I'm going to ask my electrician to do. I hope fishing the #10/3 thru the steel conduit with #6 wires in there won't be a problem. The good news is, the breaker box is also in the kitchen. As far as some of the other replies go, I have no intention of going against the code, but as I said in my first post, I got conflicting answers from licensed electricians, and just wanted to clarify things. |
#7
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electrical questions - cooktop and oven
If any licensed electrician told you anything other than using two separate
circuits, stay away from him. Fishing a new wire next to an existing wire in a conduit is sometimes a pain. Depending on the size of the conduit, it might be easier (and faster) to use the existing #6 wire to pull 2 completely new sets of wire. wrote in message oups.com... My suggestion: leave the existing 60 amp wire and box, change its breaker to 40 amps, and use it for the 40 amp load. For the other load, run a separate, new, 30 amp line with a new box. Cheers, Wayne Thanks Wayne. That's what I'm going to ask my electrician to do. I hope fishing the #10/3 thru the steel conduit with #6 wires in there won't be a problem. The good news is, the breaker box is also in the kitchen. As far as some of the other replies go, I have no intention of going against the code, but as I said in my first post, I got conflicting answers from licensed electricians, and just wanted to clarify things. |
#8
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electrical questions - cooktop and oven
I had this come up at a friends. The wire was plenty heavy, and the
breaker box a LONG way away, with all plastered basement cielings. so we put in a sub panel in the kitchen to serve the 2 circuits and saved lots of work! |
#9
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electrical questions - cooktop and oven
As long as you have a cabinet or some place to hide it. I don't think you're
allowed to hide it behind the stove, and most people don't want to look at it all the time. wrote in message ups.com... I had this come up at a friends. The wire was plenty heavy, and the breaker box a LONG way away, with all plastered basement cielings. so we put in a sub panel in the kitchen to serve the 2 circuits and saved lots of work! |
#10
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electrical questions - cooktop and oven
This is what I got from the NEC handbook 2005 (Article 220, table
220.55): "..the branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch-circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range." The handbook also explains (has a picture 210.21) how to pick tap conductors when installing oven and cooktop on the same circuit under 210.19(A)(3) Exception No. 1. Table 220.55 lists the max demand for a 12KW range as 8kW (derating it assuming the range is not used to its full capacity). The handbook has an example that shows how to get a combined rating for multiple appliances. In my case, the cooktop is rated at 9.6kW, and the oven is at 7.2kW. According to their formula, my combined maximum load is 10.4kW which requires 43.3 amps. Is anybody familiar with all this? According to this rule, shouldn't I be able connect the cooktop and the oven to the same circuit (60 amp)? Thanks. Matt |
#11
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electrical questions - cooktop and oven
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#12
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electrical questions - cooktop and oven
Speedy Jim wrote:
wrote: This is what I got from the NEC handbook 2005 (Article 220, table 220.55): "..the branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch-circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range." The handbook also explains (has a picture 210.21) how to pick tap conductors when installing oven and cooktop on the same circuit under 210.19(A)(3) Exception No. 1. Table 220.55 lists the max demand for a 12KW range as 8kW (derating it assuming the range is not used to its full capacity). The handbook has an example that shows how to get a combined rating for multiple appliances. In my case, the cooktop is rated at 9.6kW, and the oven is at 7.2kW. According to their formula, my combined maximum load is 10.4kW which requires 43.3 amps. Is anybody familiar with all this? According to this rule, shouldn't I be able connect the cooktop and the oven to the same circuit (60 amp)? Thanks. Matt Yes, I would agree with your summary. Note that the branch circuit is limited to a max of 50 Amp rating, so you would replace the 60A breaker with a 50A unit. On a side note, if the raceway will be used as the equip ground (raceway does not contain a grounding conductor), I would verify the integrity of the raceway connections (fittings) to perform as an effective grounding means. Jim I havn't looked at this stuff since about 1903 but my reading of the code is: 210.19A3 requires the circuit for a range to be at least the rating of the range and/or cooktop however 422.10A allows the branch circuit for household cooking units to be sized from 220.55 220.55-table-note 4 allows combining the KVA values and treating as a single unit 220.55-table-note 1 the value that can be used for your units is 8KW +(5x5%) = 10KW = 41.7A @ 240V (this is different from the value you came up with but still a 50A circuit) 210.19A3-exception 1 allows tap conductors to your cooktop to be rated 20 amps (or larger) if the circuit they are tapped from is protected at 50 amps and tap conductors are large enough for cooktop and the tap is only as long as it needs to be (this requires you to reduce the 60A circuit to 50A as noted in Jim's post) 422.30 requires a disconnect for the units 422.31 allows a circuit breaker to be used as the disconnect but only if in sight of the appliances or if equipped with a device to lock it open (not likely in your case) 422.33A allows an accessible plug and receptacle to be used as the disconnect (that is one reason ranges are commonly connected with plugs) 422.33B allows a plug and receptacle to be used as disconnect for a range if it can be reached by removing a drawer 422.16B3 allows wall mounted ovens and cooktops to be cord and plug connected if the plug and receptacle are rated for the temperature they are exposed to 210.21 allows a receptacle to be sized acording to 220.55 (instead the unit KVA size) (Presumably you need to figure out a disconnecting means - I don't know what is common for hardwired units. Good question for the inspector.) bud-- |
#13
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electrical questions - cooktop and oven
220.55-table-note 1 the value that can be used for your units is
8KW +(5x5%) = 10KW = 41.7A @ 240V (this is different from the value you came up with but still a 50A circuit) You are right: 8 + ( 8 x 24%) = 9.92. (I had used 8.4kW instead of 7.2kW, but forgot to update in the post.) 422.31 allows a circuit breaker to be used as the disconnect but only if in sight of the appliances These are going to be hard-wired, but the circuit breaker (panel) is also in the kitchen (right across from the oven and cooktop), so I assume I'm covered there. I'll reduce the circuit to 50 amps. (BTW, I already have a #6 cable there.) Thanks Bud, thanks Jim. |
#14
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electrical questions - cooktop and oven
Thanks Jim, thanks Bud.
220.55-table-note 1 the value that can be used for your units is 8KW +(5x5%) = 10KW = 41.7A @ 240V (this is different from the value you came up with but still a 50A circuit) Bud, you are right. For 7.2kW, combined kW is 8 + 8 x 24% = 9.92. (My calculations were based on 8.4kW instead of 7.2, and I forgot to update the post.) 422.31 allows a circuit breaker to be used as the disconnect but only if in sight of the appliances or if equipped with a device to lock it open (not likely in your case) The circuit breaker (panel) is actually in the kitchen (just across the oven and the cooktop), so I assume I'm OK. I'm going to reduce the circuit to 50 amp (use the existing 6 gauge cable). Thanks again. |
#15
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electrical questions - cooktop and oven
no, no, and subject to local code the box is probably too small.
a licensed master electrician who sees the jobsite and your appliance and its manual will give you the best answer. and the electrical permit inspector will make sure he's correct. see also http://www.faqs.org/faqs/electrical-wiring/part1/ |
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