■A 4-wire power supply connection must be used when the appliance is installed in a location where grounding through the neutral conductor is prohibited. Grounding through the neutral is prohibited for (1) new branch-circuit installations, (2) mobile homes, (3) recreational vehicles, and (4) areas where local codes prohibit grounding through the neutral conductors.
If using a power supply cord:
Use a UL listed power supply cord kit marked for use with clothes dryers. The kit should contain:
■A UL listed 30-amp power supply cord, rated 240 volt minimum. The cord should be type SRD or SRDT and be at least 4 ft (1.22 m) long. The wires that connect to the dryer must end in ring terminals or spade terminals with upturned ends.
■A UL listed strain relief.
If your outlet looks like this:
■At least 5 ft (1.52 m) long.
4-wire receptacle (14-30R)
Then choose a 4-wire power supply cord with ring or spade terminals and UL listed strain relief. The 4-wire power supply cord, at least 4 ft (1.22 m) long, must have four 10-gauge copper wires and match a 4-wire receptacle of NEMA Type 14-30R. The ground wire (ground conductor) may be either green or bare. The neutral conductor must be identified by a white cover.
If your outlet looks like this:
3-wire receptacle (10-30R)
Then choose a 3-wire power supply cord with ring or spade terminals and UL listed strain relief. The 3-wire power supply cord, at least 4 ft (1.22 m) long, must have three 10-gauge copper wires and match a 3-wire receptacle of NEMA Type 10-30R.
If connecting by direct wire:
Power supply cable must match power supply (4-wire or 3-wire) and be:
■Flexible armored cable or nonmetallic sheathed copper cable (with ground wire), protected with flexible metallic conduit. All current-carrying wires must be insulated.
■10-gauge solid copper wire (do not use aluminum).
