Hello from a new guy with some questions.

[ActionDave]

The first step to wisdom is to discard the quality of looking down on how someone has completed a task; but to try to assign a code violation to it instead....

Truer words have never been spoken (or in this case typed) in the North American Electrical World. Just because what I see is not the way I would have done the job does not mean the work is incorrect or inferior.

Matter of fact, some of the work I have done ended up not being the way I would have done it.

 

[jumper]

I have an Ugly's and a pdf copy of the NEC but the thing reads like a lawyer wrote it. So whatever advice I can get here would be greatly appreciated.

Steve

Welcome.

Although not written by lawyers, the NEC is adopted as a legal document.

I highly suggest taking a code course that will help familiarize yourself to the layout. The key to using an NEC is figuring out where the information you need is located.

The index is always a good place to start.

Also as to why the NEC can be confusing or intimidating at first, from 90.1 at the beginning of the code:

(C) Intention. This Code is not intended as a design specification
or an instruction manual for untrained persons.

You gotta work and study the code to try and understand it.

 

[Aleman]

Ok, I can see that part of what was done is legal. Since I didn't describe it too well...and yes I need to learn terminology. We have 2 control panels that are fed from a 460 volt 30 amp circuit. I call it a 30A because the feeders come from a service panel with a 30A breaker. At the top lugs of panel #1 disconnect switch, 3 wires are tapped off and run to panel #2 disconnect. The run to panel 2 is about 20 feet.

What I left out before is the real reason I called it half assed work. In each of the 2 panels there are no fuses, no circuit breakers inline with the feeds off the disconnect switches. According to article 240.21 the taps must terminate in a breaker or fuses. So, this is a code violation. Thanks for pointing me to where taps are described.

The same outfit built a lot of our panels. Typically they have no fuses or breakers other than the overloads in the motor starters and contactors. The control transformers usually come with fuse blocks so those are protected. So, these panels are a problem and one of the reasons I was hired. We will be slowly replacing a lot of these.

Once again thanks for the pointers and good advice. It is a huge help and is exactly what I was hoping for on this forum. And I appreciate you guys not being too hard on me.

Steve

 

[kwired]

Ok, I can see that part of what was done is legal. Since I didn't describe it too well...and yes I need to learn terminology. We have 2 control panels that are fed from a 460 volt 30 amp circuit. I call it a 30A because the feeders come from a service panel with a 30A breaker. At the top lugs of panel #1 disconnect switch, 3 wires are tapped off and run to panel #2 disconnect. The run to panel 2 is about 20 feet.

What I left out before is the real reason I called it half assed work. In each of the 2 panels there are no fuses, no circuit breakers inline with the feeds off the disconnect switches. According to article 240.21 the taps must terminate in a breaker or fuses. So, this is a code violation. Thanks for pointing me to where taps are described.

The same outfit built a lot of our panels. Typically they have no fuses or breakers other than the overloads in the motor starters and contactors. The control transformers usually come with fuse blocks so those are protected. So, these panels are a problem and one of the reasons I was hired. We will be slowly replacing a lot of these.

Once again thanks for the pointers and good advice. It is a huge help and is exactly what I was hoping for on this forum. And I appreciate you guys not being too hard on me.

Steve

More details are necessary before one can say it is not code compliant. If all the conductors on this 30 amp circuit are 30 amp conductors then you have no taps, you just have a circuit feeding multiple outlets, loads, etc. We do the same thing with simple 15 and 20 amp 120 volt circuits all the time, we feed multiple outlets from the same circuit and use the same size conductor throughout the entire circuit. Now you could run into a situation where you are not allowed to supply more than one utilization equipment on the circuit, but we don't have enough detail to make that determination at this point.

You also could have control circuits consisting of smaller conductors tapped to this circuit without additional overcurrent protection in some cases.

You can see that the NEC is complex, what you do to comply with one section can effect how you comply with another section.

It would be a good idea to take some classes that cover the NEC, like maybe at a local community college, or even some offered CEU classes somewhere. You don't have to be licensed to take CEU's, most are willing to accept anyone that will pay the course fee.

 

[zbang]

A couple of things-
Read the NEC up through the 400's, but the first time or two skip any parts that don't apply to your job, like residential load calculations or over 600 volt work. Read the interesting parts of 500 and 600. Go back and start from the front again. Repeat. It'll start to make sense.

Also, get your hands on a modern copy of Practical Electrical Wiring by Richter; many libraries have it (20th edition is current, I think). It'll explain a lot, too. (Back in the '70s, my local library copy saw a lot of wear just from me.)

 

[Strathead]

Welcome to the forum. My two cents. Along with the suggestion that you take a code class, I suggest you also study some basic electricity. Either take a class or at least, get a book. I don't intend to be in any way condescending, but I suspect from your writing that you don't have emough understanding of electrical theory to understand the deeper answers to some of your questions, (which are not bad questions). Please don't hesitate to clarify if I am wrong. For example, understading how various phases of the AC sine wave interact with each other. This would clear up your confusion about shared neutrals. It is easy to say the phases cancel, or add on the neutral, but it is a whole lot easier to troubleshoot or do maintenance if you know why.

Do you know and comprehend Ohm's laws? Both are important. I know electricians that know the laws, but they don't understand what they really mean. Like if I decrease voltage, why does the light dim? Or what is a parrallel circuit. If you do have this understanding, then go the next steps... Kirchoffs laws. power quality. There is always another step in the learning. Some of these guys here make me feel very inadequate!

 

[augie47]

Ok, I can see that part of what was done is legal. Since I didn't describe it too well...and yes I need to learn terminology. We have 2 control panels that are fed from a 460 volt 30 amp circuit. I call it a 30A because the feeders come from a service panel with a 30A breaker. At the top lugs of panel #1 disconnect switch, 3 wires are tapped off and run to panel #2 disconnect. The run to panel 2 is about 20 feet.

What I left out before is the real reason I called it half assed work. In each of the 2 panels there are no fuses, no circuit breakers inline with the feeds off the disconnect switches. According to article 240.21 the taps must terminate in a breaker or fuses. So, this is a code violation. Thanks for pointing me to where taps are described.

The same outfit built a lot of our panels. Typically they have no fuses or breakers other than the overloads in the motor starters and contactors. The control transformers usually come with fuse blocks so those are protected. So, these panels are a problem and one of the reasons I was hired. We will be slowly replacing a lot of these.

Once again thanks for the pointers and good advice. It is a huge help and is exactly what I was hoping for on this forum. And I appreciate you guys not being too hard on me.

Steve

The NEC is certainly not an easy document ... I've had my head in it for better than 50 years and still learn every day.
As kwired pointed out, you may not have a violation...most likely you do,,,
Prior to apply the "tap rules" read 240.2 for the description of "Tap Conductors". As long as your wire is sized correctly for the over-current device, it is not a tap.
From your description, my guess would be they "doubled-up" on the line lugs of the first disconnect which in all probability will be a violation (most small disconnect lugs are not rated for such)

 

[Strathead]

From your description, my guess would be they "doubled-up" on the line lugs of the first disconnect which in all probability will be a violation (most small disconnect lugs are not rated for such)

And something no one here would ever doooooooooooooooooo! Really, I probably wouldn't do it, but I would also probably overlook it as long as everything is tight and looks OK.

 

[kwired]

And something no one here would ever doooooooooooooooooo! Really, I probably wouldn't do it, but I would also probably overlook it as long as everything is tight and looks OK.

Many 30 amp and smaller devices with "pressure plate" style terminations are designed for one or two conductors.

 

[Aleman]

Welcome to the forum. My two cents. Along with the suggestion that you take a code class, I suggest you also study some basic electricity. Either take a class or at least, get a book. I don't intend to be in any way condescending, but I suspect from your writing that you don't have emough understanding of electrical theory to understand the deeper answers to some of your questions, (which are not bad questions). Please don't hesitate to clarify if I am wrong. For example, understading how various phases of the AC sine wave interact with each other. This would clear up your confusion about shared neutrals. It is easy to say the phases cancel, or add on the neutral, but it is a whole lot easier to troubleshoot or do maintenance if you know why.

Do you know and comprehend Ohm's laws? Both are important. I know electricians that know the laws, but they don't understand what they really mean. Like if I decrease voltage, why does the light dim? Or what is a parrallel circuit. If you do have this understanding, then go the next steps... Kirchoffs laws. power quality. There is always another step in the learning. Some of these guys here make me feel very inadequate!

Hey Strathead, I like your handle. I understand electricity pretty well and graduated many years ago from an electronics school. I have worked with machines all of my adult life. I can wire them and make them run, modify them, put a PLC in a machine and make it run however I want it to. I build my own guitar amps from scratch. I understand how phases interact together. My problem is preconceived notions about how electrical is supposed to be installed not matching up to how it is really supposed to be. Up till now most of my electrical work was machine level or wiring up a garage etc. So now I am doing more electrical work and what I do I want to do right. That's all really. I'm not afraid to read books or dig for info. Joining this forum is part of my digging. You guys are speeding up the process for me. As I get more familiar with the code I will be asking fewer questions. My electrical work is primarily branch circuits, adding outlets, running conduit, switches, installing new branch circuits etc. Since I am basically by myself I try to learn by studying example work. But the examples are not consistent. Some guys ran a ground wire, some used the conduit for ground. Some have a neutral for every hot and some share the neutral, even though the hots are separate phases in both cases. So I need to understand what is right. So I conclude that some who have come before me might not have known the correct methods either. You guys have already cleared up a lot of things for me. Thanks.

Steve

 

[Aleman]

The NEC is certainly not an easy document ... I've had my head in it for better than 50 years and still learn every day.
As kwired pointed out, you may not have a violation...most likely you do,,,
Prior to apply the "tap rules" read 240.2 for the description of "Tap Conductors". As long as your wire is sized correctly for the over-current device, it is not a tap.
From your description, my guess would be they "doubled-up" on the line lugs of the first disconnect which in all probability will be a violation (most small disconnect lugs are not rated for such)

That's what they did. But the disconnect switch is a 60A switch so it takes 2 smaller wires ok. I would have to look but the wires are no larger than 8awg. The connections are ok. I just didn't know if it is ok per code to do that. From my understanding of the code pointed out earlier the taps are ok provided there are protection devices on the load. Usually there will be a main circuit protection directly after the disconnect. Many disconnects have fuses or breakers built in. In these panels I was referring to, the wires off the disconnect go into a terminal block and disperse to various loads like drives, motor starters etc. The drives are unprotected for example by anything other than the breaker for the incoming circuit. Which is 30amps and many of these drives are running small motors that take 2-3 amps. So I would consider these to be basically unprotected.

You are right the NEC doesn't seem like an easy document. I'll keep reading it. Maybe it will start sinking in

 

[Aleman]

A couple of things-
Read the NEC up through the 400's, but the first time or two skip any parts that don't apply to your job, like residential load calculations or over 600 volt work. Read the interesting parts of 500 and 600. Go back and start from the front again. Repeat. It'll start to make sense.

Also, get your hands on a modern copy of Practical Electrical Wiring by Richter; many libraries have it (20th edition is current, I think). It'll explain a lot, too. (Back in the '70s, my local library copy saw a lot of wear just from me.)

I like your advice, thanks.

 

[Aleman]

A couple of things-
Read the NEC up through the 400's, but the first time or two skip any parts that don't apply to your job, like residential load calculations or over 600 volt work. Read the interesting parts of 500 and 600. Go back and start from the front again. Repeat. It'll start to make sense.

Also, get your hands on a modern copy of Practical Electrical Wiring by Richter; many libraries have it (20th edition is current, I think). It'll explain a lot, too. (Back in the '70s, my local library copy saw a lot of wear just from me.)

Found out the local library system has one, put in a request, should get it next week. It's older, based on the 2005 code. Should be good for me I would think. Thanks!

 

[Strathead]

Hey Strathead, I like your handle. I understand electricity pretty well and graduated many years ago from an electronics school. I have worked with machines all of my adult life. I can wire them and make them run, modify them, put a PLC in a machine and make it run however I want it to. I build my own guitar amps from scratch. I understand how phases interact together. My problem is preconceived notions about how electrical is supposed to be installed not matching up to how it is really supposed to be. Up till now most of my electrical work was machine level or wiring up a garage etc. So now I am doing more electrical work and what I do I want to do right. That's all really. I'm not afraid to read books or dig for info. Joining this forum is part of my digging. You guys are speeding up the process for me. As I get more familiar with the code I will be asking fewer questions. My electrical work is primarily branch circuits, adding outlets, running conduit, switches, installing new branch circuits etc. Since I am basically by myself I try to learn by studying example work. But the examples are not consistent. Some guys ran a ground wire, some used the conduit for ground. Some have a neutral for every hot and some share the neutral, even though the hots are separate phases in both cases. So I need to understand what is right. So I conclude that some who have come before me might not have known the correct methods either. You guys have already cleared up a lot of things for me. Thanks.

Steve

Good that makes it easier to explain things to you. Some of the guys here are really smart and talk on a level that can spin my head around some time. Now any of them reading this will know they can be technical with you. I only built a couple of pedal effect myself. It was fun. I have thought about adding an overdrive channel to my very old Fender Twin, but never actually decided to tackle it. Anyway,

The ground thing... I just don't use the conduit as a ground. Many people believe that you can't in certain applications. Depending on where you work, there are often specifications that are more stringent than the code, and I don't believe I have ever seen a project that had specs (specifications) where the conduit was allowed to be used as a ground. It is legal, but the restrictions are enough that I just don't agree with it. Basically, all connection HAVE to be made up tight. If I were an ispector, I would discourage this practice. Make the electrician get up on a ladder and verify tightness of EVERY connection and if one were found to be loose, then require them to pull grounds in all conduits. They would get the hint. That said it is still legal.

Regarding neutrals. The issues are far more complex. Some people contend that there is a safety issue in sharing between phases. Particularly for a maint person, when working upstream from the shared point. Care must be taken. With sharing, cost is less, number of conductors in a conduit is less, wire amount is less. Then there is the issue of harmonics created by electronic loads that is a whole field of problems by itself. From a design perspective though, remember, all of you panels use a "shared" neutral from the source.

As you get deeper and deeper in to the code you will find that many things that seemed good work practice, are actually illegal or marginal, and things that you thought were bad work practice are better electrically. One example that immediately comes to mind is grooming inside a panel. It is great to neatly bundle all of your wires. It is far better for heat dissipation to have them less aesthetic, and loose to allow cooling air flow.

Lastly, I suggest you subscribe to ECM magazine if you don't already. You can get it for free. Do a Google search.

 

[Aleman]

Good that makes it easier to explain things to you. Some of the guys here are really smart and talk on a level that can spin my head around some time. Now any of them reading this will know they can be technical with you. I only built a couple of pedal effect myself. It was fun. I have thought about adding an overdrive channel to my very old Fender Twin, but never actually decided to tackle it. Anyway,

The ground thing... I just don't use the conduit as a ground. Many people believe that you can't in certain applications. Depending on where you work, there are often specifications that are more stringent than the code, and I don't believe I have ever seen a project that had specs (specifications) where the conduit was allowed to be used as a ground. It is legal, but the restrictions are enough that I just don't agree with it. Basically, all connection HAVE to be made up tight. If I were an ispector, I would discourage this practice. Make the electrician get up on a ladder and verify tightness of EVERY connection and if one were found to be loose, then require them to pull grounds in all conduits. They would get the hint. That said it is still legal.

Regarding neutrals. The issues are far more complex. Some people contend that there is a safety issue in sharing between phases. Particularly for a maint person, when working upstream from the shared point. Care must be taken. With sharing, cost is less, number of conductors in a conduit is less, wire amount is less. Then there is the issue of harmonics created by electronic loads that is a whole field of problems by itself. From a design perspective though, remember, all of you panels use a "shared" neutral from the source.

As you get deeper and deeper in to the code you will find that many things that seemed good work practice, are actually illegal or marginal, and things that you thought were bad work practice are better electrically. One example that immediately comes to mind is grooming inside a panel. It is great to neatly bundle all of your wires. It is far better for heat dissipation to have them less aesthetic, and loose to allow cooling air flow.

Lastly, I suggest you subscribe to ECM magazine if you don't already. You can get it for free. Do a Google search.

I just hope they don't get too technical because my head will spin. I am a nuts and bolts guy and the level of comprehension only goes so deep

Could I then look at these 2 examples as a minimum requirement? Because regarding the ground wire I am of the same opinion as you, I like to have the wire in there because I distrust loose connections. I mean, it won't hurt anything to have the ground in there and the majority of the work I have seen does have an extra conductor for ground. Same with separate neutrals, I can see it isn't necessary in some cases but it wouldn't hurt to have them provided there is room in the raceway. Good point on the wire bundling.

 

[kwired]

I just hope they don't get too technical because my head will spin. I am a nuts and bolts guy and the level of comprehension only goes so deep

Could I then look at these 2 examples as a minimum requirement? Because regarding the ground wire I am of the same opinion as you, I like to have the wire in there because I distrust loose connections. I mean, it won't hurt anything to have the ground in there and the majority of the work I have seen does have an extra conductor for ground. Same with separate neutrals, I can see it isn't necessary in some cases but it wouldn't hurt to have them provided there is room in the raceway. Good point on the wire bundling.

I have used raceway for grounding a large percent of the time for years. It really depends somewhat on the application. I do a lot of work at grain storage and handling facilities. Majority of the loads are motors, and everything around is steel. If you have a loose raceway fitting, it really does not matter as far as having a low impedance to clear a ground fault. There is so much more steel in the structure that it will have a lower impedance than the raceway or your pulled EGC will ever have. I know that goes against what the NEC says but it is also reality.

Separate neutrals. There are pro's and con's either way on this one. First thing is to share the neutral you must have a proper multiwire circuit where the common neutral is carrying unbalanced current from the associated ungrounded conductors and is not shared between random ungrounded conductors. This practice not only effects how much copper is used by eliminating extra conductors, but it also effects the heat created within the conductors in a raceway. A conductor carrying only unbalanced current is not counted as a current carrying conductor for the purposes of ampacity adjustments and can make a big difference between having a raceway with all 12AWG conductors installed or a raceway with 10 AWG or even 8AWG being necessary to supply the same loads because of the additional heat contributed by all the extra neutral conductors. Either install is code compliant, but there is the design choice there depending on what may be important to the designer, sometimes less cost prevails, sometimes an improvement in performance may prevail.

 

[Aleman]

I have used raceway for grounding a large percent of the time for years. It really depends somewhat on the application. I do a lot of work at grain storage and handling facilities. Majority of the loads are motors, and everything around is steel. If you have a loose raceway fitting, it really does not matter as far as having a low impedance to clear a ground fault. There is so much more steel in the structure that it will have a lower impedance than the raceway or your pulled EGC will ever have. I know that goes against what the NEC says but it is also reality.

Separate neutrals. There are pro's and con's either way on this one. First thing is to share the neutral you must have a proper multiwire circuit where the common neutral is carrying unbalanced current from the associated ungrounded conductors and is not shared between random ungrounded conductors. This practice not only effects how much copper is used by eliminating extra conductors, but it also effects the heat created within the conductors in a raceway. A conductor carrying only unbalanced current is not counted as a current carrying conductor for the purposes of ampacity adjustments and can make a big difference between having a raceway with all 12AWG conductors installed or a raceway with 10 AWG or even 8AWG being necessary to supply the same loads because of the additional heat contributed by all the extra neutral conductors. Either install is code compliant, but there is the design choice there depending on what may be important to the designer, sometimes less cost prevails, sometimes an improvement in performance may prevail.

That all makes sense. I can see from a design standpoint that the shared neutral is a better way to go, if it is done right. As far as ground goes, I will use my judgement depending on the job. Some of my work is mounted to steel structure, and come to think of it the circuit I found with no separate ground was mounted to steel.

 

[Strathead]

That all makes sense. I can see from a design standpoint that the shared neutral is a better way to go, if it is done right. As far as ground goes, I will use my judgement depending on the job. Some of my work is mounted to steel structure, and come to think of it the circuit I found with no separate ground was mounted to steel.

I always believed, and discussions with the inspectors I respect most has also revealed a belief that unserstanding the intent of the codes is important. There may be someone out there who disagrees, but I think all of us have intentionally violated codes at some point. Similar to what kwired is saying. Knowing why they wrote the rule lets you and the inspector know when overlooking it doesn't compromise the installation.

That said, the purpose of a grounding conductor (the conduit is a conductor in this application) is to provide a path back to the source adequate to carry amperage enough to trip the breaker if a ground fault occurs.

The shared neutral issue is different. The perspective I give you is, would you insist on conduit and wire in your new house? It is definitely a more fail safe installation, but the cost is more than the benefit to me. Some people definitely would be willing to pay the difference. There are only a few instance where I would require separate neutrals, if it were my decision. Other than loads with harmonics, that would likely be an operation where 24 hour uninterrupted power is mandatory, so I would already be spending far more on power supplies anyway. Not that this is an all inclusive list, just the main points.