Manual says 8 AWG for a 30 A dryer?

[marmathsen]

Just curious if any one else has run across this?

I have a client who needs me to run a circuit for an electric dryer in a residence. LG model DLEX4000B.

I was sent a link to the electrical requirements portion of the instructions by the general contractor and was surprised to see the statement:

If the branch circuit to appliance is 15 ft. (4.5 m) or less in length, use UL (Underwriters Laboratories) listed No.-10 AWG wire (copper wire only), or as required by local codes. If over 15 ft. (4.5 m), use UL-listed No.-8 AWG wire (copper wire only), or as required by local codes.

https://gscs-manual.lge.com/DFZ/MFL70442676/en-us/main.html#topic_31

A 16 ft branch circuit for a standard 30A dryer requires an 8 AWG conductor?!? What?!

It does say "or as required by local codes", so I feel like I can just run a 10 AWG but that just seemed crazy to me.

Rob G
Seattle

 

[ramsy]

A 16 ft branch circuit for a standard 30A dryer requires an 8 AWG conductor?!? What?!

Typical computer blue screen of death when voltage drops below 100v, happens with most TV’s, and other iOT gadgets.

In this case the appliance heat-element load may be enough to drop voltage on #10cu below 100v line-to-neutral, where the Switch Mode power supply operates.

 

[RonPecinaJr]

What is the kilowatt rating of the dryer?

 

[suemarkp]

You're not going to get enough voltage drop on a #10 to matter even if it was 100' long. This is probably boiler plate language that they cut and pasted from an extension cord chart... Dryers almost always use cord and plug connections. I don't know why they care what the wire in the wall is (cu -vs- al) when it lands on a receptacle and not their dryer. I wonder if they are talking about the cord whip that goes on the dryer. CU and #8 for >15' make more sense in that case.

 

[TwoBlocked]

Aren't branch circuit conductors required to be rated at 125% of load?

 

[fastline]

OEM is just covering their 6. I'd put on #10 all day long. Especially when you look at data plate to see like 23A.

 

[infinity]

Aren't branch circuit conductors required to be rated at 125% of load?

Not if the load is non-continuous.

IMO the "or as required by local codes" allows you to ignore the #8 nonsense.

 

[Tyler C]

I wonder if they meant to write 150'. The fact that it says 15 twice makes me think not, but 150' is about where I'd be thinking about up sizing for this. Maybe even a little shorter - would have to do the math.

 

[Eddie702]

Maybe it dries really fast LOL

 

[marmathsen]

What is the kilowatt rating of the dryer?

Not sure. The literature doesn't say, it just refers to the nameplate, which I hadn't seen.

My guess based on experience is somewhere around 23A @ 240V, 5520W

Rob G
Seattle

 

[marmathsen]

I wonder if they meant to write 150'. The fact that it says 15 twice makes me think not, but 150' is about where I'd be thinking about up sizing for this. Maybe even a little shorter - would have to do the math.

I was thinking the same. 150' made more sense

Rob G
Seattle

 

[brycenesbitt]

In this case the appliance heat-element load may be enough to drop voltage on #10cu below 100v line-to-neutral, where the Switch Mode power supply operates.

Switch mode power supplies can have a very very wide range..
But they're almost all designed to work at 100V +- 5% because of Japan (100V 50Hz)

 

[Joethemechanic]

I wonder if they meant to write 150'. The fact that it says 15 twice makes me think not, but 150' is about where I'd be thinking about up sizing for this. Maybe even a little shorter - would have to do the math.

Seems odd that they would manufacture a dryer that wouldn't fit into a standard dryer footprint. If I bought one for a replacement, and I had to change the branch circuit I'd be ticked off

 

[Dennis Alwon]

Not if the load is non-continuous.

IMO the "or as required by local codes" allows you to ignore the #8 nonsense.

A dryer has a motor load and a heater load both of which require 125%. However 5000 watt and 5500 watt dryers are still under 24 amps.

 

[infinity]

A dryer has a motor load and a heater load both of which require 125%. However 5000 watt and 5500 watt dryers are still under 24 amps.

I'm thinking that an appliance that doesn't operate at full load for more than 3 hours is not a continuous load regardless of what is has in it.

 

[Dennis Alwon]

I'm thinking that an appliance that doesn't operate at full load for more than 3 hours is not a continuous load regardless of what is has in it.

IDK-- you may be correct but either way it doesn't change the 30 amp requirement

 

[infinity]

IDK-- you may be correct but either way it doesn't change the 30 amp requirement

Agreed.

 

[Jraef]

Aren't branch circuit conductors required to be rated at 125% of load?

Only if the load is “continuous”, defined as 3 hours or more at full load. As a generalization, “electric heating” is considered to be continuous loads, and a dryer is a heating appliance. But dryers CYCLE the heat on and off, and generally do not have a “3+ hour” setting on them, so are not included in being considered “continuous”.

 

[Eddie702]

Only if the load is “continuous”, defined as 3 hours or more at full load. As a generalization, “electric heating” is considered to be continuous loads, and a dryer is a heating appliance. But dryers CYCLE the heat on and off, and generally do not have a “3+ hour” setting on them, so are not included in being considered “continuous”.

Agree.