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I am moving a dryer and need to wire a new 240V outlet. The outlet is 75 feet from the panel. I'm installing a 30 Amp GFCI breaker and converting the 3 wires to 4 wires. I had thought that 10/3 wire would be thick enough, but I'm not sure if the distance of the wire requires a thicker gauge wire.

The photo below shows that the dryer draws 27 Amps (4 for motor and 23 for heater).

If I do need to use 8 gauge wire, is braided OK? Thanks.

Dryer electrical specs label

Update

Thanks for all the answers below. In case it helps others, I ended up using 10/3 NM-B Romex cable. It was a bit of a pain to pull through the joists but I'm sure much easier than 8 gauge would have been. It's been running the dryer for about 6 months so far with no issues.

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    Don’t forget the 80% rule for derating continuous loads.
    – Jon Custer
    Mar 20, 2023 at 14:31
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    I think at 75ft will be within the range of 10 gauge, but there is no rule saying you can't use a larger gauge wire.
    – crip659
    Mar 20, 2023 at 14:41
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    @jay613 that is incorrect. You not only can, but should, use a GFCI breaker in that case. But most likely it can be correctly rewired for 4-wire.
    – Ecnerwal
    Mar 20, 2023 at 14:57
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    Yes, I am planning on converting to 4 wire. There are instructions to do so on the back of the dryer. Thanks.
    – shackleton
    Mar 20, 2023 at 15:03
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    Also if you're using EMT metal conduit, that provides ground. ALSO, if you're working with #10 (and that's fine BTW), conduit allows you to use THHN wires, which are available in stranded wire. #10 solid is a bear to work with. Mar 20, 2023 at 18:37

2 Answers 2

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Use the size of breaker specified in the dryer instructions. It sounds like the whole dryer (heating element included) is 23A, which is absolutely typical and normal of 99% of dryers, since it perfectly fits the 24A limit of a 30A circuit. A 27A dryer would be unusual.

At 240 volts, 75 feet isn't nearly far enough to worry about voltage drop. I don't even check the voltage drop calculator til 170 feet (150' in Canada because of their dumb rule). For 120V, half that. All this stuff has been calculated by experts, it's not going to randomly get hot unless you botch the terminal connections.

If you want to use #6 aluminum to save some money, that's equivalent of #8 copper, so you can have best of both worlds. "Oh no, you said not to botch the terminal connections! Isn't using aluminum wire the definition of that?" Actually no. Science says "failing to use a torque driver to set screw torques" is the definition of that. Even pro electricians can't torque any better than their spouses - they tested that. Aluminum wire works fine when torqued and when placed on terminals properly rated for aluminum. (neither of which was done in the 1970s).

Use types of wire legal for home wiring, such as NM-B, SE-R, THHN/XHHW in conduit, etc. At #8 and larger size these will be stranded which is an NEC requirement. Don't bother looking for solid #8, you won't find it except in bare grounds.

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  • Bob: Why do you have your conduit bender? Alice: I've got to get this solid 4/0 through an elbow. :)
    – FreeMan
    Mar 20, 2023 at 18:15
  • @harper: Thanks. I'm not concerned about the breaker. I'm using a 30A, which should be sufficient as that's what I've been using on the old circuit for many years. The question was more about the gauge of wire. The current wire run is about 25 feet. The new location will require 75 feet. It sounds like you are saying that both from a safety (wire heat) and voltage drop standpoint, I am OK with 10 gauge wire, correct?
    – shackleton
    Mar 22, 2023 at 20:16
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    @Shackleton yes, for a 240V load, I don't even bother doing a voltage drop calculation until at least 150'. You are confused about wire heat. Your 75' wire will run exactly the same temperature as your 25' wire. Yes, it will make 3x as much heat total, but spread out over 3x the distance - thus, the same at any given point. This is true for any length of wire. The thermal limits in 310.15(B)(16) are perfectly adequate, note you'll be constricted further by 240.4(D) (limiting 15-30A wire to the lowest thermal rating). Mar 22, 2023 at 20:44
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I recommend 8 gauge. You don't want any possibility of the wire getting hot from constant use. The motor pulls a heavy load on start-up and then the heating element unless it's gas. But with a 75' pull... personally, I wouldn't trust 10 gauge not to become a future headache. "If I do need to use 8 gauge wire, is braided OK?" YES

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    There aren't "chances" to wires getting hot from normal use. This is all engineered into the electrical codes, see Table 310.15(B)(16) though a 30A circuit is further constrained by 240.4(D) so it's never going to get particularly warm. Voltage drop isn't a concern for 240V until at least 150' (but you are correct 75' is the plcae to start thinking about it for 120V). Mar 21, 2023 at 22:07

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