converting clothes dryer receptacle from 3 prong to 4 prong

[Cleveland Apprentice]

I have a customer that is moving into a house in a week and his dryer is a 4 wire hook-up. The receptacle in that house is 3 prong. He has asked me to convert the receptacle to a 4 prong. The romex is old style 10/3 with no ground. Parts of the basement is finished ceiling and it would be a real hassel to replace the entire length with 10/3 with ground. I was wondering if it would be ok to run a #10 egc to the receptacle and grounding to a H2o pipe on ceiling and if this would violate any codes. Thanks.

 

[iwire]

1. Leave the existing three wire receptacle in place.
   
2. Change the four wire cord on the dryer to a 3 wire cord.
   
3. Be sure to bond the dryer frame to the neutral connection where the cord connects.

See 250.40 exception for details.

 

[dana1028]

I was wondering if it would be ok to run a #10 egc to the receptacle and grounding to a H2o pipe on ceiling and if this would violate any codes. Thanks.

Yes this would violate section 250.104(A) - in the 'old' days what you propose was acceptable because the interior water piping was considered part of the electrode system, but this was changed [in 1993 I believe] so that the interior water piping after the 1st 5 ft. is no longer considered part of the electrode system.

Per 250.104(A) you can connect your EGC to any grounding electrode.