Original source: Mike Holt Forums
I'm working on the design for a new hotel, and the owner provided me a prototype, which shows two(2) washer machines on a dedicated circuit. As per article 210 of NEC it shall be dedicated per washer machine, but is that only for dwelling, or shall that apply to commercial as well? Thanks.
Better look at the nameplate data on the washing machines and see if both are under 80% of your circuit capacity. I would run separate circuit for each though.
Why second guess? Give 2, share the neutral, call it good. Sent from my E6782 using Tapatalk
+1 I'd be surprised if you'll be able to squeeze two on the same circuit.
The NEC does not require separate circuits for each machine.
There are countless millions of machines that share the same 20 amp circuit. Most washers draw 7-9 amps, what makes you think this would be a problem sharing a 20 amp circuit?
It's been awhile since I've done hotel jobs but those large washers that I often dealt with were Swedish that you practically needed a interpreter for to understand the nameplate data.
20A x 80%= 16A. 9A + 9A= 18A. Seems like some of those countless millions of washers might be on overloaded circuits. And we're not even considering startup.
Where is this 80% rule you speak of in the NEC?
I believe it's 384-16(c). Don't quote me on that, it's been a while.
Or maybe I'm thinking of the UL white book...
No, it's the inverse of the 125% upsizing of a circuits capacity that needs to be applied to continuous operation of equipment. So if 2 washers running for a minimum of 3 hours at 8 amps a piece: 8ampX2=16a x125% = 20amp circuit or in other words a 20 amp circuit can only be loaded up to 80% which equals 16 amps if used on a continuous basis. I would have to check but maybe another article may apply, in regards to any fixed equipment that exceeds over 50% of a circuits capacity shall have its own circuit.
I believe that the 50% limit only applies if there are other receptacle outlets on the circuit.
Thanks Golddigger, I thought there was more to it. Which may apply in this case as there would probably be 2 receptacles on the OP's circuit.
A washing machine is not a continuous load so there is no 80% involved. Two 10 amp machines can be on a 20 amp circuit.
To bad those commercial washing machines are 11 amps a piece. Just guessing. Ha
By the definition, you are absolutely right in saying that washing machines are not continuous loads. I look at this situation a little differently though. The only time, with rare exceptions, that you would even have two washers to put on the same circuit would be in a commercial laundromat or apartment complex laundry room setting. In these settings, it would be obviously impossible for a washer motor to run for at least three hours straight without interruption, due to the fact that the machines' washing cycles would be shorter then that period of time. What does seem probable, however, is that these machines could be run for eight or ten hours straight with only 3 to 4 min shutdowns for a new load to be thrown in. For my money, that is close enough to a continuous load to warrant 1 extra 20A breaker and homerun. Certainly not code requirement for a dedicated homerun, but certainly good practice IMHO.
First, 80% does not apply to laundry, second start up is not an issue. In fact breakers are built to have inrush delay. Does not apply to washing machines as they wont be running for 3 hours periods in resi.
Read previous post 17 where I excluded resi... Sent from my SCH-I545 using Tapatalk
This has create a buzz! Well, if it is not required to be dedicated, I think I will trust the prototype set of drawings I was given and leave it as it is. But if at the end, if I find a spare, then I will split it in two separate circuit just for sake. Thank you so much.
