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Thread: Need help finding an electrical code rule

  1. #1
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    Need help finding an electrical code rule

    I was on a job site, and the electrician wired the 10 HP air compressor with a 3 phase 480v and a 230 single phase circuit. Both circuits go to the same box on the compressor. The 480 feeds the motor apparently through the contactor (but the compressor was setup for 230v 3phase). And 230 single phase feeds the contactor start/stop.

    Edit: the 480 has a new disconnect from a 480 panel and the 230v comes from a breaker in the 230v 3phase panel. To make matters worse, the AC was wired up with a 30 amp 230v 3 phase breaker.

    I know this is illegal, as anyone who took any electrical safety or lock out tag out class can state.

    I just want to find the code printed out about it.

    This electrician actually stalked me by sitting at my coffee place for probably an hour just to wait for me to bitch that I dont know what I am talk about, but he has at least 10 separate violations in this room alone. What a person who hasn't left high school yet lol.
    Last edited by Country Metals; 08-09-2022 at 10:02 PM.

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    Re: Need help finding an electrical code rule

    I'll have to research that. I have installed a great many motor controls with 120 volt single phase controls operating 480 volt motors. I'm not aware that is prohibited. One facility has a panic system. From numerous places in the facility anyone can shut the whole place down pushing any one of several emergency stop buttons. The fire alarm also can shut down. Most all controls work on single phase & I'm not a fan of miles of control wiring run at 480 or even 277.

    We lock out/tag out the disconnect for a motor, downstream of the contactor. I guess you could lock out a disconnect upstream from the contactor, but locking out motor power would still prevent unintended start up.
    Last edited by Willie B; 08-09-2022 at 10:10 PM.
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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Willie B View Post
    I'll have to research that. I have installed a great many motor controls with 120 volt single phase controls operating 480 volt motors. I'm not aware that is prohibited. One facility has a panic system. From numerous places in the facility anyone can shut the whole place down pushing any one of several emergency stop buttons. The fire alarm also can shut down. Most all controls work on single phase & I'm not a fan of miles of control wiring run at 480 or even 277.

    We lock out/tag out the disconnect for a motor, downstream of the contactor. I guess you could lock out a disconnect upstream from the contactor, but locking out motor power would still prevent unintended start up.
    The facilities I work in can have 5 different voltages within a box, but it only has 1 feed and a bunch of transformers.

    If this guy wired something with 2 different feeds from 2 different panels, how do you lock it out with 1 lockout.

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    Re: Need help finding an electrical code rule

    I have a steak cutter at 3 different facilities that have 480 feed, 120 ac, 48dc, 24dc, 12 DC and 5dc. But still only 1 feed coming in

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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Country Metals View Post
    The facilities I work in can have 5 different voltages within a box, but it only has 1 feed and a bunch of transformers.

    If this guy wired something with 2 different feeds from 2 different panels, how do you lock it out with 1 lockout.
    You don't run different voltages to the machine. Different voltages are in a motor control. If you are referring to a self contained machine with numerous motors, usually a testing laboratory seal & listing. Then it's (I believe) one power source.

    Off hand I'm thinking of two machines, one has two 240 volt three phase power sources with labeling that it is powered by more than one source. The other has two power supplies with gobs of control components.

    All machines in industrial applications require disconnect in sight, or lockable. In most cases control work involving multiple voltages are upstream from the motor. There, a disconnect is mounted near the machine.

    Until I read up on the subject, I'll say a self contained machine CAN have more than one power source, but labeling & disconnects must be provided for each source. That's only my logic, not yet found in code.
    Last edited by Willie B; 08-10-2022 at 07:27 AM.
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    Re: Need help finding an electrical code rule

    I havnt looked either but just stopped to say I can feel for you with some of those knobs they turn loose in maint. I was doing some job, the machine stopped. I went to see (this isnt the first time we saw this) but the genius is tearing it all apart, gonna rewire the whole thing and I ask why??? Well,,, it cant work like this. Really, why not? Well its wired wrong. It is? Yes, it cant work like this. I got to say,,, oh really,,, so until yesterday it had been running 25 years 24/7 and someone snuck in here last night and rewired the whole thing wrong?

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    Re: Need help finding an electrical code rule

    Well, I havent even said this guy put plain Jane galv dry boxes in a wash down area and his plugs on the machine are 10 feet in the air, 2 feet off the ceiling.


    Sounds a little bad I think.

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    Re: Need help finding an electrical code rule

    On another forum way long ago had a guy come along and ask, wow, went to do something to the air comp and thought the wire looked strange. It was installed 18 yrs ago with a 12 cable by dads bud, the "electrician" from work, got a 7.5 motor. Ran fine. Lot of those guys can manage a whole career without opening a book of any kind.

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    Re: Need help finding an electrical code rule

    I've worked on equipment before and saw huge signs that said "equipment has more than one power source" make sure all power sources are locked out before starting any repairs" or something like that.



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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Sberry View Post
    I havnt looked either but just stopped to say I can feel for you with some of those knobs they turn loose in maint. I was doing some job, the machine stopped. I went to see (this isnt the first time we saw this) but the genius is tearing it all apart, gonna rewire the whole thing and I ask why??? Well,,, it cant work like this. Really, why not? Well its wired wrong. It is? Yes, it cant work like this. I got to say,,, oh really,,, so until yesterday it had been running 25 years 24/7 and someone snuck in here last night and rewired the whole thing wrong?
    He must be a retired Government worker from some other field who nevertheless "knows it all". At least he didn't go into politics...

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    Re: Need help finding an electrical code rule

    There is no problem with any of it as you described. The starter has 240 volt coil so he had to feed it with 240 control power circuit. Then the compressor was 480 3 phase no choice there either he gave the lines 480 and the starter kicks in when pressure switch make the other half of 240 that isn't on coil other side already and kicks it in and compressor runs. You can't get those voltages out of the same panel. No he didn't need a 480 or even a 277 coil so it could either.

    Coil voltage surely doesn't have to be 480 or even 277 just because the lines are.

    Contactors, Motor Starters and relays do not need coil voltages to match the lines.

    You can pull two legs off a 3 phase breaker if you want. Or one leg off a 2 pole if you want. Perfectly legal.

    All that is done legally all over every day.

    The 30 amp feeding the control would need #10 wire throughout or a over current device downline to properly protect what size wire was used.
    Last edited by danielplace; 08-10-2022 at 10:20 PM.

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    Re: Need help finding an electrical code rule

    Well the compressor was wired as a 30 amp 230v 3 phase system to begin with, with a 5 foot whip on it. He changed it for some very odd reason.

    To make things sound the way they are. The AC in a 2x4 stud room that is 4 feet wide ID and 6 feet deep and 12 foot tall. Osb on outside of studs all the way around.

    The AC is in the middle which is 3 feet wide from the tank so you can't get around it.

    If your standing at the open wall, the 480v disconnect and main 480 panel is on the right side, and the wire feeds tight across the AC to the control box. The 230v 3 phase panel with a 30 amp breaker already in it is on the other side of the left wall. The 230v 2 pole line runs to the same box on the left side of the AC. Both the 230 and 480 wires are less then 4 feet long total. The AC is not anchored down so it can vibrate away. All the ports are on the other side inside the room. The filter and oil drain are inside the room as well, on the other side of the AC.

    So in order to do any work, you have to disconnect both the 230 and the 480 lines just to do any work or get to the shut off. The start/stop control is also out of reach being inside the room, so that is why you have to use the 230v breaker as the on/off switch.

    Pretty screwed up way of doing good work I'd say. Please let me know if I'm wrong.
    Last edited by Country Metals; 08-11-2022 at 03:49 PM.

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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Country Metals View Post
    Well the compressor was wired as a 30 amp 230v 3 phase system to begin with, with a 5 foot whip on it. He changed it for some very odd reason.

    To make things sound the way they are. The AC in a 2x4 stud room that is 4 feet wide ID and 6 feet deep and 12 foot tall. Osb on outside of studs all the way around.

    The AC is in the middle which is 3 feet wide from the tank so you can't get around it.

    If your standing at the open wall, the 480v disconnect and main 480 panel is on the right side, and the wire feeds tight across the AC to the control box. The 230v 3 phase panel with a 30 amp breaker already in it is on the other side of the left wall. The 230v 2 pole line runs to the same box on the left side of the AC. Both the 230 and 480 wires are less then 4 feet long total. The AC is not anchored down so it can vibrate away. All the ports are on the other side inside the room. The filter and oil drain are inside the room as well, on the other side of the AC.

    So in order to do any work, you have to disconnect both the 230 and the 480 lines just to do any work or get to the shut off. The start/stop control is also out of reach being inside the room, so that is why you have to use the 230v breaker as the on/off switch.

    Pretty screwed up way of doing good work I'd say. Please let me know if I'm wrong.
    Can you take and post pictures showing all of this?

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    Re: Need help finding an electrical code rule

    I dont like posting any of my customer pictures but I'll draw it out and post it later.

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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Country Metals View Post
    I was on a job site, and the electrician wired
    Curious what your interest is on this job site ? Who owns it ? who is paying the bill ? Why no inspections of the work if it is a job site ?

    Just observations of a electrician not doing his job how you would like ?

    How does it affect you that it was done this way ? What do you hope to accomplish in this discussion as it relates to what was done and what should have been done or you think should have been done.

    The first post you were saying lots of things were wrong that aren't. Now it seems it is just how it was run physically and no proper access. Is that breaker switch duty. Seems like it does though effectively act as a remote start/stop switch, eh ? Then if you were to access the othe side of compressor like to work on it it you would also have access to the actual start/stop switch and hopefully shut off the breaker in the 480 panel. That is why only qualified personnel should not be messing with it.

    Sounds like a crowded area. Does sound like the wiring is not run the best routes maybe ??? What should he have done went on the floor or overhead ? what is the answer you think that would have been better way ?
    Last edited by danielplace; 08-11-2022 at 08:20 PM.

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    Re: Need help finding an electrical code rule

    Let's say it's in my best interest to keep the actual owner of the equipment in great standings. This small business is an extremely small entity of a very large part of what he does. He just likes this for some reason.

    I didnt like the electrical at first, but when I realized who did it, I'm just making sure that crap is being done.

    I'm still wondering how an electrical inspection can be completed if only 2/3 of the equipment is in place an wired up. That's also not including the glychol system and the boiler system, which the electric for that isnt completed either. Isnt even started. It's obvious it's all part of the same system.

    Everything is just so fishy with what is going on.

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    Re: Need help finding an electrical code rule

    My bud said he was in another country. Went to work on a machine, walked over to the disc was wired and piped to it, shut it off, went under to unhook the motor and pow, big ole shock knock him senseless and laying under a machine wondering if it was gonna end there and how. When he finally came to investigated and found that feed had been abandoned and was fed from a unit on the other side of the wall.

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    Re: Need help finding an electrical code rule

    Lock-out, tag-out is often misunderstood and utilized improperly. Osha states that EVERYTHING that could cause harm must be disconnected, power turned off and ANY energy, kinetic or potential be released and all controls whether electrical, mechanical, hydraulic etc be locked out and tagged by every person performing work, additionally each person is responsible to care for their individual lock and tag. I remember when they started getting hardcore on lock-out tag-out special procedures and methods had to be developed at our company(LARGE INDUSTRIAL COPPER COMPLEX) with some lockouts having a dozen components that had to be locked & tagged and maybe 2 or 3 gang lock devices on each one, 20 or more locks in some cases. We had stuff that ran on 44000 volts down to 480 and 120 volts, plus instrumentation voltages, control voltages etc on the AC side and some serious DC in the PRECIPITATORS, over 100,000 DC IIRC, and the overhead cranes were 250 DC, some control voltages on the DC side too The facts, it's your A$$, cover it!
    Last edited by CAVEMANN; 08-13-2022 at 10:29 PM.

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    Re: Need help finding an electrical code rule

    I see individual machines in industrial applications where they have a disconnect at the remote building where there is a transfer switch to connect a generator, in the electrical room there is a ground fault disconnect feeds a buss cabinet then a disconnect for each of 5 sets of feeders. From there it runs outward to 5 areas in one building & 1 in another building. Two more services come directly from the transformer. There are several dozen motor controls & a motor control center. A master control center controls SOME of the machines in the facility.
    Downstream of the motor control or VFD, typically hundreds of feet away is a disconnect for each motor, or machine typically in sight of said machine.

    It's near impossible to lock out every component supplying a machine. We lock out the specific machine being worked on, not everything upstream.

    Worst is when there is a malfunction in the control equipment. The electrical contractor left only a partial ladder diagram of thousands of miles of control wiring. Some enclosures contain many dozens of power sources. Management frowns on total plant shutdowns, so we keep that work to a minimum. Most is 480 volt, but thankfully control circuitry is 120 Volt throughout.
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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Country Metals View Post
    Well the compressor was wired as a 30 amp 230v 3 phase system to begin with, with a 5 foot whip on it. He changed it for some very odd reason.

    To make things sound the way they are. The AC in a 2x4 stud room that is 4 feet wide ID and 6 feet deep and 12 foot tall. Osb on outside of studs all the way around.

    The AC is in the middle which is 3 feet wide from the tank so you can't get around it.

    If your standing at the open wall, the 480v disconnect and main 480 panel is on the right side, and the wire feeds tight across the AC to the control box. The 230v 3 phase panel with a 30 amp breaker already in it is on the other side of the left wall. The 230v 2 pole line runs to the same box on the left side of the AC. Both the 230 and 480 wires are less then 4 feet long total. The AC is not anchored down so it can vibrate away. All the ports are on the other side inside the room. The filter and oil drain are inside the room as well, on the other side of the AC.

    So in order to do any work, you have to disconnect both the 230 and the 480 lines just to do any work or get to the shut off. The start/stop control is also out of reach being inside the room, so that is why you have to use the 230v breaker as the on/off switch.

    Pretty screwed up way of doing good work I'd say. Please let me know if I'm wrong.
    Sounds like there was not enough room for what they planned to install. Maybe both feeds should have been in SJ cord and plugged in with twist locks. Serve as yet another disconnect and a way to get them out of the way quickly. If both breakers are in sight of equipment the breakers in each panel is sufficient for a disconnect though.

    Other two choices are overhead 12 feet or a trip hazard across the floor. SJ and twistlock cord caps and outlets would add couple hundred bucks to the installation though. Going overhead probably even more.

    How is it run in Greenfield Flex ?

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    Re: Need help finding an electrical code rule

    oops , delete
    Last edited by yooper; 08-16-2022 at 07:00 PM. Reason: forgot quote

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    Re: Need help finding an electrical code rule

    Quote Originally Posted by Sberry View Post
    My bud said he was in another country. Went to work on a machine, walked over to the disc was wired and piped to it, shut it off, went under to unhook the motor and pow, big ole shock knock him senseless and laying under a machine wondering if it was gonna end there and how. When he finally came to investigated and found that feed had been abandoned and was fed from a unit on the other side of the wall.
    This is why I always use a non contact tester { beeper } , you may get a false positive indication sometimes { due to induction } but they never miss a hot wire .

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    Re: Need help finding an electrical code rule

    Quote Originally Posted by yooper View Post
    This is why I always use a non contact tester { beeper } , you may get a false positive indication sometimes { due to induction } but they never miss a hot wire .
    As long as it's not an SEU cable, it won't ring on one of those. I've heard so many stories of people shutting off circuits then sticking their hands in without verifying it's really dead, they'll usually blame someone else but the truth is nobody is responsible for your safety but you. If you don't know how to test before sticking your mitts in there, and don't do LOTO, you have no business in there.
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