Can someone give me code references or insight regarding service changes and how they affect existing range and dryer circuits. I'm upgrading an old 3 wire service to a 200 amp (disconnect feeding a main lug panel) 4-wire and am wondering if I need to install new 4 wire range and dryer circuits. This is an old flat top cinder block bungalow and needless to say, major destruction work would be required.
This may be up to your AHJ, but as I stated on another board, I think you should replace the cables & outlets or purchase service entrance equipment that has room for a couple of more 2 pole breakers & extend the 3 wire cables into the new service entrance box.
Although three wire feeds were allowed for these types of loads, they were not allowed to be fed from a sub-panel, which is what you will be doing when you upgrade the service.
The current requirement is 250-140(3). The old reference was 250-60(c).
[This message has been edited by Tom (edited 06-28-2001).]
Few things are harder to put up with than the annoyance of a good example.
Re: Existing range and Dryer 3-wire circuits#2228 06/28/0106:13 PM06/28/0106:13 PM
I will always try to include a 3 to 4 wire upgrade in such a service change, however if we would like to delve into the NEC:
250-140's key word is 'existing'
250-142(b) EX #1 states; The frames of ranges, wall mounted oven, counter-mounted cooking units, and clothes dryers under the conditions permitted for existing installations by Section 250-140 shall be permitted to be grounded by a grounded conductor
Ok, so tape that puppy up & off to the N-bar!
BUT WAIT !
90-5(b) Permissive Rules nice if you do it, but don't gotta!
Ok, so on to the G-bar???
Art 100, Special Permission; basically what Tom said
So can we do a poll of AHJ's here? Door #1--Noodle Bar Door #2--G-bar Door #3--rejected until a 4-wire set-up
[This message has been edited by sparky (edited 06-28-2001).]
Re: Existing range and Dryer 3-wire circuits#2229 06/29/0112:55 PM06/29/0112:55 PM
I would use the neutral bus, because a dryer and a range use the grounded conducter for several 120 volt circuits within the unit. For the timers and lighting. I would never intentionally put current onto a ground detail.
Re: Existing range and Dryer 3-wire circuits#2230 06/29/0102:23 PM06/29/0102:23 PM
If the connection is in the main panel were neutral and ground are bonded, I don't see a difference between doors 1 and 2. Since it is carrying current, I would treat it as a neutral. Door 3 is the safe way.
Re: Existing range and Dryer 3-wire circuits#2231 07/04/0108:02 AM07/04/0108:02 AM