I wired for a new cooktop using #12, 2 wire Romex with ground wire – long before the unit arrived on-site.
The installation instructions say that it requires a #10 ground wire.
The unit is 3800 watts (no amps given). The unit is 220v. I calculate the amps as 17.25 (3800/220). Watts = Volts X Amps, so Amps = Watts / Volts.
Rather than buying a roll of #10, 2 wire Romex and reroughing, can I just add a bare or coated #10 wire from the unit back to the main panel , or does it need to be in some sort of sheathing, or must it be within the same jacket as the power feeds?
Thank you for your help,
Frankie
Edited 8/26/2005 10:20 am ET by Frankie
Replies
I dont think your calculation are right. all the range I have use was 30 amp wire. usually the ground is one size smaller than the hots so if it calls for #10 then more likely you will need #8 for your hots. and it might need a four wire.
What do the directions say about the other conductors and breaker size?
The usual computation is amps*1.25 for breaker size. That puts you a bitover 20amps.
I expect 10-2/g NM will work better for you.
The instructions do not mention wire guage - other than ground wire - breaker size or amps used.Not sure how you calculated breaker size using 1.25. Can you elaborate, or as my high school math teacher would say "Show your work."Thanks,F
I've never roughed in a cooktop only unit with anything less than #10 wire. I recommend that you re-wire with tens. Check to see if your unit has a neutral. If youhave two hots a neutral and a ground you need to wire it with 10-3/wG.
If you haven't drawn blood today, you haven't done anything.
Unit has L1, L2, and ground symbol.Thanks,F
This is a really small cooktop, one or two burners, right? 3800 Watts and #12 wire sounds like it would be small.
-- J.S.
I spoke with the fine folks at Gaggenau and they did not have the info either (weird), but with a bit of cajoling and consulting others in the tech help coral, they determined the cooktop required a 20 amp breaker and #12 wire. They could not offer an explaination why a #10 wire is required for the ground but I am doing that. My solution is running a #10 ground wire through 3/8 or 1/2 Greenfeild (whatever I have in storage). It is the least expensive way to go. 60' of 10/3 wire costs $50. The #10 wire cost $12. Greenfeild in left over from another job - not free, but already paid for and taking up space.Thank you all for your help.BTW - It is a 2-Burner cooktop.Frankie.There he goes—one of God's own prototypes—a high powered mutant of some kind never even considered for mass production. Too weird to live and too rare to die.—Hunter S. Thompson
from Fear And Loathing In Las Vegas
That is not kosher.All wires need to be run in the same cable or conduit.There is an exception for running a separate ground wire for upgrading old ungrounded receptacles, but that does not apply here.Personally I would just use the #12 ground in the NM.
Before you go to all that work, trace the origin of that requirement for #10. Grounds can sometimes be smaller than the current carrying conductors, but I've never heard of a requirement for a ground bigger than the hot. It's almost certain to be bogus, and the #12 ground you have in the Romex is all you really need. It sounds like somebody at the mfg. did some cut and paste on their computer from the docs for a larger model, and didn't proofread.
-- J.S.
I'd agree with J.S.