3 prong 220V outlets

[DonTx]

Does the NEC require the use of 4 prong 220V outlets for dryers or are the old 3 prong still allowed in new construction?

Donald

[Richard Moore]

Donald...

If I'm reading my NEC right...

250.140 New installations (circuits/outlets) for Cord-and-Plug-Connected equipment must comply with 250.138

250.138, basically, requires an equipment grounding conductor to be run with the power carrying conductors.

That would be 4-wire/4-prong for a dryer.

So, no, I don't believe you can have a 3-prong dryer (or range) outlet in a new home.

[Steve Knight]

Donald,

I agree with Richard. New construction requires a 4 wire/4 prong dryer connection. If buyer has been using dryer at a previous house it may have the wrong pigtail and the pigtail might need to be changed for use in a new home.

[DonTx]

Thanks everyone, that's what I needed.

Donald

[hausdok]

Hi Donald,

I don't know if this will help. It is from an 8-year old edition of Wiring Simplified by H.P. Richter and W.C. Schwan and is based on the 1996 NEC.

From Chapter 14 - Wiring of Heavy Appliances, Page 116.

Clothes Dryers: An electric dryer is a 120/240-volt appliance. Wire it as you would a range. The 1996 Code, in Section 250-60, now requires a 3-pole, 4-wire grounding type 30-amp receptacle as shown at K of Fig. 14-1, and a 4-wire pigtail cord similar to that used for a range but with smaller wires.

The 1993 and earlier Codes, in Section 250-60, permitted the frame of the dryer to be grounded to the neutral of the three wires provided it was not smaller than No. 10. Service-entrance cable with a bare neutral was permitted where it ran from the service location directly to the dryer receptacle.

The plug and receptacle serve as the disconnecting means.

ONE TEAM - ONE FIGHT!!!

Mike