Motor Starter Wiring

Just to update everyone, I have looked into it and agree with the low voltage control circuit, I have ordered the 120v coils and was about to order new thermal units but found out mine are the correct size already, this unit must have been wired for 480 then half assed rewired for 240. I am not a professional, but I never back down from anything. I will sit back and learn what I need to proceed correctly, this will be done correctly and will not cost me thousands of dollars to have a professional do it.
 
dcheff said:
Just to update everyone, I have looked into it and agree with the low voltage control circuit, I have ordered the 120v coils and was about to order new thermal units but found out mine are the correct size already, this unit must have been wired for 480 then half assed rewired for 240. I am not a professional, but I never back down from anything. I will sit back and learn what I need to proceed correctly, this will be done correctly and will not cost me thousands of dollars to have a professional do it.
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Did you find or purchase a control transformer ?
 
I talked with the electrical supplier and they told me to just use the 120 I already have for the control circuit. I have single and 3 phase all around my shop
 
dcheff said:
I talked with the electrical supplier and they told me to just use the 120 I already have for the control circuit. I have single and 3 phase all around my shop
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The supplier should not, in my opinion, make recommendations that are not up to code. I will strongly suggest that you fuse the 120 vac for the requirements of the coils only and keep that part of any 120 vac used on the machine separate. Still not to code but gives added protection. I will stick to the control transformer approach for safety.
 
Once again uncle harry strikes with the correct answer. Suppliers only know what they heard Joe Blow did while taking his order at the sales counter. And other than taking your order and taking you to lunch they are not much good for anything. 1 in 20 really knows his ****. Finding one of those is like striking gold and you should probably take him to lunch!

UL allows a secondary power feed for industrial control equipment. You SHALL mark the enclosure with the highest voltage rating present and also mark with a suitable engraved placard stating "SEPARATE SOURCE CONTROL POWER". Thus as a warning to anyone opening the enclosure that there is more than one disconnect to be found. As previously stated the voltage from this source shall not exceed 120v. The most popular and available choices being 24vac and 120vac.

As an after thought, you might be pleasantly amazed of what YOU may LEARN with the right questions from a good electrician on a $75 service call. Like most true craftsmen, electricians love to discuss their craft. Generally if they seem secretive, it is probably because he does not know much.
 
rdhem2 said:
Once again uncle harry strikes with the correct answer. Suppliers only know what they heard Joe Blow did while taking his order at the sales counter. And other than taking your order and taking you to lunch they are not much good for anything. 1 in 20 really knows his ****. Finding one of those is like striking gold and you should probably take him to lunch!

UL allows a secondary power feed for industrial control equipment. You SHALL mark the enclosure with the highest voltage rating present and also mark with a suitable engraved placard stating "SEPARATE SOURCE CONTROL POWER". Thus as a warning to anyone opening the enclosure that there is more than one disconnect to be found. As previously stated the voltage from this source shall not exceed 120v. The most popular and available choices being 24vac and 120vac.


As an after thought, you might be pleasantly amazed of what YOU may LEARN with the right questions from a good electrician on a $75 service call. Like most true craftsmen, electricians love to discuss their craft. Generally if they seem secretive, it is probably because he does not know much.
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Jim brings to mind another point regarding remote power sources. NFPA 78 2012 states in 13.2.4.1 "The color ORANGE shall be used to identify ungrounded conductors that remain energized when the main supply circuit disconnecting means is in the off position. This color identification shall be strictly reserved for this application only." (the old code specified yellow as the required color for remotely "active" conductors). Again, NFPA 79 is a code specifically directed toward industrial machinery. Any machine that can be used in industry naturally applies even if it's in a hobby situation. My only intent in submitting all of this is safety. PS: NFPA 79 has an updated version. I just can't justify shelling out over 50 bucks + shipping for a few paragraphs of "improvement".
 
NFPA 79 applies to industrial manufactured equipment but not necessarily equipment wired in place or customer supplied wiring, which field control wiring falls into that category. We often supply secondary voltage control circuits to machinery that is wired in the field. All of the above mentioned safeguards need to be in place and in addition, a secondary voltage supply must have a separate disconnecting means clearly marked at the controller location.
Refusing to pay for help in a situation where making a mistake can cost you large sums in replacing equipment or sustaining injury is foolish, in my opinion and reeks of being cheap. Most electricians who work on industrial control equipment have taken years to learn their trade and could probably do this job in a matter of an hour or so, not including supplying the control circuit from the source to the equipment itself. Being too cheap to have an expert do a job like this could easily result in an injury and/or liability issue- but of course, you're not "scared" of that so have at it. You've been given good advice here, it's up to you to heed it or not.

Bob
 
Thank you John, I came here for an additional source of info, there are obviously a bunch of smart people here. This has nothing to do with being cheap, saving money is just a bonus. I'm a mechanic and went to college for aviation maintenance where I took a ton of electrical classes. I'm a little rusty on it for sure but I do understand it. The whole part of doing it myself is old fashioned pride in myself and the fact that as a mechanic I have to figure things out, its in my nature.

Just so you guys know your lathes and mills are very dangerous, you shouldn't use them if your not a professional machinist, you should hire a machinist to do your work for you. This is what it looks like when you tell me to hire an electrician.

Aside from the heckling I truly appreciate all of the help I have received on this

Sent from my XT1080 using Tapatalk
 
Well, I wish you well on this install. I hope that everything goes well and your starter works first time when you test it. I stand by my comments for one reason- as an electrician with 38 years experience, mostly installing and wiring industrial equipment and servicing that equipment later, the absolute worst repairs and rewiring jobs I've had to do were when a customer did his own wiring. It usually involved replacing very expensive parts... After seeing in your first post that the motor would be connected to "true 440V 3 phase" then alluding to connecting it to 480V power, I started to wonder if there may be a problem? I truly hope that isn't the case.

Besides, there is a big difference between heckling and concern for safety. Have you ever seen a 480V controller explode?

Bob
 
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