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| Subject - electric hand dryers | |
| HOOSIER | I am preparing a bid to install 8 electic hand dryers, they are rated at 8.5 amps each (277v). From the panel to dryers is approx. 150', any issues with splitting these up to 2 dryers per circuit? My first thought would be to pull 2 12-3 mc's and sharing the neutral between two circuits... so, each circuit would have two dryers and sharing a neutral with the other circuit in the mc.. any issues on this? It's a bid job of course and I realize this is not the perfect set up.. any input would be appreciated. |
| lctrc789 | Hoosier, I really don't see a problem with this because if these are hand dryers that are only on for 30 seconds or so they are not continious loads and won't be on that long for the demand factor. Even though 17 amps is right at 125 % and more then 80% of a load. Let me ask you if this is 277 voltage 3 phase why not run 12-4 and install 3 circuits per M/C cable instead of 12-3..If you use 12-3 you will be using 600 feet of wire and if you use 12-4 you would use 300 feet of 12-4 and 150 feet of 12-3. perhaps do not install hand dryers right next to one another on the same circuit or install one in womens bath then one in mens bath etc... Any one else have to say yea or nay on this. |
| frenchelectrician | i am not sure what the code allow have multi circuit there but the question is the handle tie[s] for three phase breaker. I know one guy i know him he did explain that dont need handle tie at all but i dont know about your local area might required or not and the other question with 277 volt hand dryers if you loose the netrual conductor what will happend if someone decided to use the hand dryer and found out it blew up if it actintally ran on 480 volt instead of 277 Volt you know what i mean ?? Merci , Marc |
| nfsus | since you are sharing the neutral and not the phases, I wouldnt use the handle ties. |
| lctrc789 | French, The 277/ volts is a single phase circuit it works like a 120 volt circuit, so if you lose the neutral it would be unlikely you would get 480 from it it would be like saying how does 120 volts work and if you lose a nuetral will you get 220, chances are slim that would happen, you would just lose the circuit and the hand dryer would not work.... The code allows multiple circuits on single and 3 phase in this case, as in 2 or 3 wire. |
| lctrc789 | You are right you do not need to tie breakers together at all here this is a single phase circuit, unlike using 2 cicuits to tie together on recpt. on 2 seperate circuits. Then you would need handle ties.... |
| devo | I personally don't like multi-wire branch ciruits because depending on where the neutral is lost you can get 480V, in this case, if both dryers get turned on at the same time....as far as two on one breaker I've always stuck to the 16 amps per 20amp ckt |
| Ryan_J | quote: Do you do commercial work, and if so, do you win bids? |
| HOOSIER | THANKS FOLKS !!!! We got this bid... appreciate your help.
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