---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Tue 05/13/08: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:15 AM - Re: off-topic question about AC electric motors (sheldon barrett) 2. 09:35 AM - Re: off-topic question about AC electric motors (Brian Meyette) ________________________________ Message 1 _____________________________________ Time: 04:15:21 AM PST US From: "sheldon barrett" Subject: Re: RV-List: off-topic question about AC electric motors If it's indeed a dual voltage motor, the name plate will indicate it...(115 v @ some amperage/230v @ half that amperage)... If the motors name plate only says 230v. then it's probably a single voltage winding and there won't be any taps to change.. It will eventually burn up running on low voltage.... Sheldon ----- Original Message ----- From: "Russ & Marilyn" Sent: Monday, May 12, 2008 7:50 PM Subject: Re: RV-List: off-topic question about AC electric motors > > Brian, > > > Remove the access cover to the wiring and check to see if the motor is > wired for lo voltage or high voltage. The internal taps may need to be > simply placed on the correct terminal. Check the motor data plate for the > correct tap arrangement. > > Russ > > > ----- Original Message ----- > From: "Brian Meyette" > To: > Sent: Monday, May 12, 2008 12:54 PM > Subject: RV-List: off-topic question about AC electric motors > > >> >> This has nothing to do with RVs, but I know there are a lot of very >> knowledgeable people out there and someone might know. >> >> The short question is - what will happen if you plug a 230v motor into >> 115vac? Will it still run, albeit weakly? >> >> If you're interested, this is the long version - I bought an air >> compressor >> that the seller said had a motor problem. Rather than just replace the >> motor, I tested it out, because sometimes you can actually buy things >> that >> are not as bad as expected, and just need a simple fix. >> >> The compressor came with a standard 15a, 115v 3-prong plug on it. So, I >> disconnected the belt driving the compressor and tested the motor by >> plugging it in. It ran fine. So, I connected the belt and let it try to >> drive the compressor. It starts and runs ok, but then runs out of steam >> and >> starts to slow down. Then the start circuit kicks in and it picks up >> speed >> again, then slows down again. >> >> So, I figured the motor was indeed bad & I'd have to replace it. But, >> after >> looking at the motor data plate to see what to order, it clearly says it >> is >> a 5 HP GE 230 volt only (not 115/230) motor. The whole thing is well >> used, >> so someone in its past must have been using it successfully. Perhaps the >> previous owner (or one before that) either had a 230v circuit with a 115v >> outlet on it (REALLY bad idea) or perhaps the guy I bought it from got it >> without a plug on the end, assumed it was 115v and put the 115v plug on >> it & >> then saw it didn't work, so he sold it. >> >> So, I am planning to put a 230v plug on it and try it in a 230v circuit. >> I >> guess I dont have anything to lose if somehow it is really 115 and I put >> 230 to it & burn it up , as I would otherwise have to replace the motor >> anyway, because it is too weak at 115v. I just wondered if it was >> feasible >> that it really is a 230v motor and all it needs is a 230v supply. >> >> What do you guys think - will a 230v motor run, but weakly, on 115v? >> >> Thanks, >> brian >> >> Checked by AVG. >> 1:08 PM >> >> >> >> >> >> >> >> > > > ________________________________ Message 2 _____________________________________ Time: 09:35:50 AM PST US From: "Brian Meyette" Subject: RE: RV-List: off-topic question about AC electric motors Thanks to all for the advice. I tried hooking it to 230v last night and it ran great. It's definitely a 230v-only motor, and there's nothing wrong with it. So the motor alone is worth way more than the price I paid for the whole compressor. Odd that it came with a 115v plug that threw me. the seller must have bought the compressor somewhere (perhaps an auction), probably without a plug, installed that 115v plug, thinking it was 115v, then sold it cuz it didnt work well. I lucked out on that transaction, as I was expecting to have to buy a new motor for it when I bought it. -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of sheldon barrett Sent: Tuesday, May 13, 2008 7:11 AM Subject: Re: RV-List: off-topic question about AC electric motors If it's indeed a dual voltage motor, the name plate will indicate it...(115 v @ some amperage/230v @ half that amperage)... If the motors name plate only says 230v. then it's probably a single voltage winding and there won't be any taps to change.. It will eventually burn up running on low voltage.... Sheldon ----- Original Message ----- From: "Russ & Marilyn" Sent: Monday, May 12, 2008 7:50 PM Subject: Re: RV-List: off-topic question about AC electric motors > > Brian, > > > Remove the access cover to the wiring and check to see if the motor is > wired for lo voltage or high voltage. The internal taps may need to be > simply placed on the correct terminal. Check the motor data plate for the > correct tap arrangement. > > Russ > > > ----- Original Message ----- > From: "Brian Meyette" > To: > Sent: Monday, May 12, 2008 12:54 PM > Subject: RV-List: off-topic question about AC electric motors > > >> >> This has nothing to do with RVs, but I know there are a lot of very >> knowledgeable people out there and someone might know. >> >> The short question is - what will happen if you plug a 230v motor into >> 115vac? Will it still run, albeit weakly? >> >> If you're interested, this is the long version - I bought an air >> compressor >> that the seller said had a motor problem. Rather than just replace the >> motor, I tested it out, because sometimes you can actually buy things >> that >> are not as bad as expected, and just need a simple fix. >> >> The compressor came with a standard 15a, 115v 3-prong plug on it. So, I >> disconnected the belt driving the compressor and tested the motor by >> plugging it in. It ran fine. So, I connected the belt and let it try to >> drive the compressor. It starts and runs ok, but then runs out of steam >> and >> starts to slow down. Then the start circuit kicks in and it picks up >> speed >> again, then slows down again. >> >> So, I figured the motor was indeed bad & I'd have to replace it. But, >> after >> looking at the motor data plate to see what to order, it clearly says it >> is >> a 5 HP GE 230 volt only (not 115/230) motor. The whole thing is well >> used, >> so someone in its past must have been using it successfully. Perhaps the >> previous owner (or one before that) either had a 230v circuit with a 115v >> outlet on it (REALLY bad idea) or perhaps the guy I bought it from got it >> without a plug on the end, assumed it was 115v and put the 115v plug on >> it & >> then saw it didn't work, so he sold it. >> >> So, I am planning to put a 230v plug on it and try it in a 230v circuit. >> I >> guess I dont have anything to lose if somehow it is really 115 and I put >> 230 to it & burn it up , as I would otherwise have to replace the motor >> anyway, because it is too weak at 115v. I just wondered if it was >> feasible >> that it really is a 230v motor and all it needs is a 230v supply. >> >> What do you guys think - will a 230v motor run, but weakly, on 115v? >> >> Thanks, >> brian >> >> Checked by AVG. >> 1:08 PM >> >> >> >> >> >> >> >> > > > Checked by AVG. 6:14 PM Checked by AVG. 6:14 PM ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.