Expert: Master Bob - 1/1/2005

Question
master bob


I am connecting a cooktop which is 8.8 kw I had a #10 wire on a 30 amp breaker connecting it, when I checked with the amprobe the reading was 34.7 amps Should I go with a 40 amp breaker and a #8 wire? the oven is 4000w so is that ok on a #10 wire on a 30 amp breaker? Or should I run a #6 wire from the panel on a 50 amp breaker and a #10 tap to the oven and a #8 tap to the cooktop? The #10 wires are already run. The panel is sixty (60) feet from the appliances. I'm not sure which way to go with this.Your input would be appreciated
Thanks";  

Answer
Hi Nick,

 Sorry for the delay....been helping my sister move into her new place....just got back.

 An 8.8 kW cooktop will draw up to 36.67 amps....and should be run with # 8 wire....on a 40 amp double pole breaker. The 4kW oven will draw about 17 amps. Where these are seperate devices...each should have it's own circuit and wiring. No...do not use #6 wire and a 50 amp breaker and tap off of it...the 50 amp breaker would never trip if there should be a problem with either device.

 So - the cooktop should be on #8/3 with ground and a 40 amp 2 pole breaker...the oven should be on #10/3 with ground...and on a 30 2 pole (unless the manufacturer specs a 20 amp 2 pole...and #12/3 wire - it's so close to being either....a very unsual rating for an oven - given those oven specs - I'd go with #10 wire [where you already have it run] and start with a 20 amp breaker - if the breaker is found to be too small for the oven...it will simply trip out...but if the wire is too small - it can overheat...).

 Hope this helps...if you need more details or have new information for me, please follow-up.

Best Wishes and Happy 2005,

Bob Osgood
Master Electrician

RKO ELECTRIC

www.rkoelectric.com