Sub-panel ?'s & adding wires to conduits

[wbrian63]

This is my first post on GJ. I've read with interest many other threads and there seems to be no shortage of electrical knowledge (and opinions ).

I'm building out the inside of a commercial space that's about 25x50. It's just one space in a very large (100x250) building. The primary function of the space will be as a wood working shop.

I've got a 125a sub-panel mounted (with main breaker), and all the circuits that flow from the panel are either in conduit or BX.

The common / ground bus bars are not cross-connected. I will bond the ground bus bar to the sub-panel housing.

It's just me in the space, and most of my big machines are 220v. My former spot just had a 60a service, and I never had trouble with tripped circuits.

The question I have is that I don't have a 125a feed for the panel from the main power source for the building. There are 2 60a fused disconnects that are vacant. They used to feed 2 A/C compressors that are no longer used, and conveniently, they terminate outside the wall adjacent to my sub-panel. All I'll have to do is replace the disconnect boxes that are unused with 2 outdoor rated junction boxes, and add a few feet of conduit and a pull-ell to reach my space.

Unfortunately, from what I could tell, they're not wired properly, as there's no common wire at all, just 2 6ga hots.

So - here are my problems:

1) I'm going to need a common and ground wire to feed my sub-panel. I'm assuming (I've not checked), that I can find connections for this in the gutter that sits below these 2 disconnects and feeds them. If not, there should be some source for common/ground in the main panel where the service comes in.

If I have to, I'll pull the wires out of the conduits in order to add the common/ground, as I'm not certain I'll be able to add them with the other 2 cables already there. The raceways are inside the building, and are 1" EMT with 5 90-degree bends from the back of the box to the disconnects for the former A/C units (which as I understand is more bends than should be allowed...).

Or is there another way?

2) Is it OK to feed the 125a main breaker in the sub-panel with a 60a feed, or do I need to replace the main breaker with a 60a unit (if that's even possible)?

My plan is to use the 2nd 60a feed for a future A/C unit, so I'll just run the conduit from the old outside disconnect to a spot inside my space where the air handler would sit and end the wires there, properly capped.

Sorry - long post - to summarize:

2 questions -

1) Is it possible to add 1 6ga and 1 10ga (I assume that's sufficient for the ground) to a 1" conduit that has 5 bends and already contains 2 6ga conductors - without pulling the existing wires out first?

2) Is it permissible to feed a 125a sub-panel with a 60a circuit?

Thanks for taking the time to read and answer.

Regards

 

[comedyman809]

if the wire feeding the panel is only 6 awg, then the panel, then 65amps is the max your panel can be.

that 6 awg has to be at the source of the electric as well and not tapped off of anything smaller, make sure the system(transformer all the way to this panel)is the proper awg all the way.

125 amp, you would need #1 wire.

although, if you intend to run only a 65 amp panel, the you should be ok but you need to be at no more than 80% of the 65 amps.

the panle can be changed from a 125 to a 65 no problem, the 125 is max allowed amps.

 

[Aceman]

1) Is it possible to add 1 6ga and 1 10ga (I assume that's sufficient for the ground) to a 1" conduit that has 5 bends and already contains 2 6ga conductors - without pulling the existing wires out first?

2) Is it permissible to feed a 125a sub-panel with a 60a circuit?

1. Yes. But you need to add a pull point. Whether it's a 4 square box or "C" condulet(you can google that to see what I'm talking about). The easiest is to unhook the existing wire, tie a rope to the end and pull the wire out pulling the rope in at the same time. Tie the new extra wires to the existing one and pull it back in using the rope or string. The added neutral must be ran with the existing (hot) circuit conductors. You can't just grab a neutral from anywhere and "T" it into the conduit.

2. Yes. But check the main breaker lugs to see if they are rated to go down to the wire size your feeding it with. You also need to make sure you are protecting the #6 upstream with a properly sized breaker also(60 amp).

if the wire feeding the panel is only 6 awg, then the panel, then 65amps is the max your panel can be.

that 6 awg has to be at the source of the electric as well and not tapped off of anything smaller, make sure the system(transformer all the way to this panel)is the proper awg all the way.

125 amp, you would need #1 wire.

although, if you intend to run only a 65 amp panel, the you should be ok but you need to be at no more than 80% of the 65 amps.

the panle can be changed from a 125 to a 65 no problem, the 125 is max allowed amps.

I agree with the bold but not everything else.

 

[wbrian63]

The disconnect I'll be pulling the power from is a 60a fused item. I'll put 60a fuses in the clips.

I'll also verify that the main breaker in my panel can handle 6ga wire properly.

I kinda figured I was going to have to pull the wires out to add the neutral.

I'll verify the source of the power to the 60a disconnect is properly sized.

I'll grab the neutral and ground from the gutter where the power is coming to the disconnect. I'll verify that they have sources at the demarc from the main feeds to the building.

To be honest, the wiring work that has been done in this building is shoddy, to say the least. The landlord offered to let me tap my electricity from a panel inside his space. I checked, and it's a 200a box with no main cutoff (if I remember correctly), and the source of the service is at the same point where I'll be pulling my power. I think code states that if the source of the power for a sub panel is not within eyesight, the sub panel must have it's own main breaker (or so I've been told - there may be distance rules as well..). For me, lack of the main breaker isn't a deal breaker, it's the fact that they powered the panel with 8ga wire!!!

Thanks for the pointers and answers!

 

[comedyman809]

1. Yes. But you need to add a pull point. Whether it's a 4 square box or "C" condulet(you can google that to see what I'm talking about). The easiest is to unhook the existing wire, tie a rope to the end and pull the wire out pulling the rope in at the same time. Tie the new extra wires to the existing one and pull it back in using the rope or string. The added neutral must be ran with the existing (hot) circuit conductors. You can't just grab a neutral from anywhere and "T" it into the conduit.

2. Yes. But check the main breaker lugs to see if they are rated to go down to the wire size your feeding it with. You also need to make sure you are protecting the #6 upstream with a properly sized breaker also(60 amp).



I agree with the bold but not everything else.

please ellaborate?? id like to better myself if i am wrong with something.

 

[mrb]

the bigger issue here is doing work in a commercial space. Working in your own home is one thing, but you cannot do work in a commercial building unless you are properly licensed -even if you own it. I dont have time to spell out all the things that could go wrong, and all the liability you assume when touching something in a commercial building, but the bottom line is -dont do it.

 

[wbrian63]

Mrb

Thanks for the head's up on the liability side. It is something I'd failed to consider.

That being said, I've been doing this type of work (I'm not licensed) for more than 20 years. I've never been in a any place where the work that was present when I started my stuff was anywhere near the quality of the work that I was doing.

When I remodeled my house about 10 years ago, I drew up the electrical plan and hired an electrician to check my design and pull the permits. I did all the work myself, with regular inspections by him to verify the quality of the job. I passed my electrical inspections on the first try. I think that the inspector was suspicious that I was doing my own work, as all the other permits for the remodel were "homeowner" permits. Here in Houston, a homeowner can pull their own permits for everything except electrical. He checked practically every socket and switch in the place, examined the main feed with a fine eye - the rough-in inspection took 2 hours for a 1500 sq ft house...

The electricians I know and respect for the quality of their work would all agree that my attention to detail and knowledge of what's right and wrong, proper and improper is solid. If I'm not sure about something, I research and find the proper answer.

That's why I've posted these questions here. I've read a number of threads on this site that lead me to believe that there are people on this forum, both licensed and non-licensed, with substantial knowledge regarding electrical installations, whose opinions I can rely upon.

I appreciate your words of caution. Unfortunately for you (assuming you're a licensed electrician), many of your brethren, both journeymen and masters play fast and loose with the codes. The result is burned up equipment and burned down buildings. It happens frequently in a big city like Houston. What I'm getting at is that saying that one must be licensed to do the type of work I'm doing doesn't hold a lot of weight with me.

I accept the risk and take the liability. Based on the quality of the rest of the post-construction wiring in this building, if something bad happens, it's not going to be my work that causes the problem...

Again - thank you for your concern. I will proceed with caution.

 

[Gooch]

Mrb


, if something bad happens, it's not going to be my work that causes the problem...

doesn't matter, if the place burns down, and it comes up that you did unlicensed electrical work they will blame you regardless of if your work caused it or not. and you will be liable for all damages. and none of your insurance policy's will cover it.

 

[mrb]

Mrb

........................

as Gooch said, none of that matters. Its illegal, and all the liability is on you. If there was a fire (whether or not your work was the cause) you will end up in court for years and just the legal fees would bankrupt the average person. I was a party involved in this exact sort of thing several years ago ( i was not on the bad side of it) and it was UGLY. All over a small amount of bootleg electrical work that had nothing to do with the fire...it wasnt even energized at the time. You would also have the other tenants and their insurance companies after you if its a multi tenant building. If the power company somehow caught wind of the illegal work, they could disconnect service and require the entire building be inspected and brought to code before reenergizing. Again..it can get really ugly -just have a licensed electrician pull permits and do the work, see if you can get your landlord to pay for it.

 

[LoneGunman]

"many of your brethren, both journeymen and masters play fast and loose with the codes. The result is burned up equipment and burned down buildings. It happens frequently in a big city like Houston."

Bu11shit, buildings are not frequently burning down do to electricians whether they are hacks or not. Any electrician that frequently burns up equipment is either going to be out of a job if an employee or out of business if he's a licensed contractor. I'm not saying there are not hacks, I've ran into a good amount of them but I have worked with a lot more that were good electricians.

"That being said, I've been doing this type of work (I'm not licensed) for more than 20 years. I've never been in a any place where the work that was present when I started my stuff was anywhere near the quality of the work that I was doing."


I'm reminded why I stay out of this forum .

 

[Aceman]

if the wire feeding the panel is only 6 awg, then the panel, then 65amps is the max your panel can be.

No. I can feed 200 amp panel with #6 if I wanted too. Maybe I just want the extra breaker spaces, etc. As long as the panel bussing is rated for the intended load to be pulled from it, it's OK.

125 amp, you would need #1 wire.

I could use #2 Copper as long as the connected load to the panel is less than #2's ampacity of 115 amps.

although, if you intend to run only a 65 amp panel, the you should be ok but you need to be at no more than 80% of the 65 amps.

80% rule is for continuous loads. Not something you have to worry about in this instance.

the panle can be changed from a 125 to a 65 no problem, the 125 is max allowed amps.

Again, panel size doesn't matter as long as it's rated for what the connected load is. I could have 5-200 amp panels connected together all being fed from one 20 amp circuit if I wanted too. As long as the load being pulled from all of them was less than 20 amps.

 

[wbrian63]

"I'm reminded why I stay out of this forum ."

Then why are you here?

I'm beginning to wonder why I even bothered asking.

I patently disagree with the concept that I could be held liable for work done properly and to code where that work happened to be in the building where an electrical fire occurred. If my work isn't the cause, then I'm not liable.

Liability means to be responsible for an event. To suggest that I would be responsible by virtue of my work being in proximity to faulty work is a fallacious argument.

I don't argue that I'd probably be caught up in the melee, but if I get held liable for safe work, then there is something wrong with my lawyer.

Not to say that it couldn't happen or didn't happen.

As for LoneGunman calling bu11sh1t - I wasn't aware you were looking over my shoulder when I witnessed the 440v 300a panel EXPLODE because a licensed HACK failed to properly tighten the lugs on the breaker that was fed with aluminum wire? Repeated heat cycling of the circuit caused sparking and carbon arcing, eventually causing an explosion when a high-amp motor startup was more than the degraded connection could handle.

That's just one of many examples I could quote - all at the same location serviced for years by the same licensed electrician...

My experiences are my own. If you were there to see what I saw and disagree, then it's your option to contest my statements. If not - keep it to yourself.

As for painting all electricians with the same brush - that was not my intention. I'm sure that the vast majority of licensed electricians follow the NEC or related codes to the letter, or even exceed the specs. However, the statement that hack wiring burns up motors and burns down houses is still a valid one.

What happens when you use a too-small conductor to feed a load? What happens when someone tries to cram 12 conductors into a conduit that's rated for 10? What happens when a hack kinks a conduit bend or fails to ream out the end of a cut piece of conduit in a junction box that's adjacent to a vibrating machine? What happens when a metal snake is used to pull wire through a raceway that already has wires present, and the end of the snake broke off years ago and was just re-bent with a pair of pliers, leaving a nice sharp edge to handily score and scrape the insulation of the other conductors in the raceway?

There is NO DOUBT that electricity is dangerous. It can damage, destroy, maim and kill in the blink of an eye. Electrical codes exist to provide guidance as to what is safe and proper for installations.

The risk is mine, and I accept that.

Let's keep the topics confined to the questions asked:

Can I feed a 125a panel from a 60a fused disconnect, so long as I don't tinker with the 60a fuses? Yes.

Is there a "trick" to adding additional conductors to an existing raceway that has a lot of turns? No - pull the existing wires back with a pull line attached, add the new conductors and pull everything back.

I've got the answers I'm looking for. I've also received more than I need.

I'm also quite certain that the cautions I've received are offered because the individuals offering them have seen far too many hack jobs done by non-licensed individuals, and they don't want more. I understand their caution, and I appreciate their concern.

Moderators - please lock this thread. I would delete it if I could...

 

[buddyboy]

if a laywer who represents himself is a fool

then:

an unlicensed electrician that has not passed the bar that gives himself legal advice is...?

 

[mrb]

what size is the service to the building? What is the available fault current? Have you performed fault current calculations?

 

[mrb]

"I'm reminded why I stay out of this forum ."

I patently disagree with the concept that I could be held liable for work done properly and to code where that work happened to be in the building where an electrical fire occurred. If my work isn't the cause, then I'm not liable.

Liability means to be responsible for an event. To suggest that I would be responsible by virtue of my work being in proximity to faulty work is a fallacious argument.

I don't argue that I'd probably be caught up in the melee, but if I get held liable for safe work, then there is something wrong with my lawyer.

Not to say that it couldn't happen or didn't happen.


There is NO DOUBT that electricity is dangerous. It can damage, destroy, maim and kill in the blink of an eye. Electrical codes exist to provide guidance as to what is safe and proper for installations.

The risk is mine, and I accept that.

You are still missing the point. This has nothing to do with the quality of work you perform (which (and I dont mean to be rude here) I would also question as most of the questions you have are of the 'if you have to ask this you have no business doing it' nature). Again the issue is what you propose to do is ILLEGAL.

The instance of this I was involved with, the legal costs got well into the low to mid six figures before the insurance company and property owner settled. There was a fire in a rooftop air conditioner that caught the roof of the building on fire causing extensive smoke and water damage. The insurance company (large national carrier) refused to pay the claim based on the fact unpermitted (note I said unpermitted, not bootleg or of questionable quality) electrical work in a room 30 or 40 feet away from the source of the fire was discovered during the insurance company's investigation.

Electrical codes do not exist to provide guidance. They exist (as adopted by your state or municipality) to provide a minimum standard for electrical installations. The code does not address illegal work, your state's penal and civil codes do.

You state the risk is yours and you accept it. This would be the case only if you were in a single occupancy building which you owned (including the land under it). The reality is, you put your landlord and the building's other tenants at risk. The exposure runs into the millions.

Do you carry insurance that is going to cover what you are proposing to do? (no because its illegal)

 

[wbrian63]

You're setting me up. And your baiting me as well.

I do not know the service size coming into the building. I hired an electrician to advise me on how to get power to my space, and he checked the service and wasn't concerned about what he found.

He did not do a fault current calculation.

So, I'll turn this around and ask if hired for a installation similar to the one I'm describing, you came out to the facility and found the service entry, determined that it was of sufficient capacity to handle the additional load being planned, checked the gutter attached to the main disconnect and discovered no issues within, found an idled 60a disconnect with the appropriate size wires present that could be used to feed the new sub-panel - would you do a fault current calculation?

I've got an idea - let's just assume for the sake of no more arguments, that all of the wiring in the space is being done in complete accordance with NEC code. Get off the fact that I'm not licensed.

I agree that licensing generally means a minimum level of competence.

That does not mean than there is no way to achieve that same level of competence if one is not licensed.

I will also concede that there is a lot of **** wiring out there in the world, and further concede that much of that work was done by individuals without the requisite knowledge necessary to undertake the wiring task.

That is not me.

I've already asked once for this thread to be locked. I'll ask again.

 

[mrb]

So, I'll turn this around and ask if hired for a installation similar to the one I'm describing, you came out to the facility and found the service entry, determined that it was of sufficient capacity to handle the additional load being planned, checked the gutter attached to the main disconnect and discovered no issues within, found an idled 60a disconnect with the appropriate size wires present that could be used to feed the new sub-panel - would you do a fault current calculation?

first, I am not a licensed electrician, so I would not perform a similar installation (even in my own building), although I could.

To address your question (which is a good one by the way):
There is not enough information provided. The size of the service, available fault current at the service (you get this from the power company after you pull your permit) come into play as does the distance from the service to this 60a disconnect and from there to the proposed panel being installed.

For example: If your 60A disco is 10 feet away from the service which happens to be 2000A service supplied by a 500kva padmount 20 feet away from the service, you are going to have around 62,000 amps available at the service, and I dont know what at the 60 amp disco but its sure going to be a heck of alot more than the 10ka rating of whatever panel you would go install. Expose a 10ka breaker to a 50ka fault and you're going to have a real problem.

There is so much more to this type of commercial work than meets the eye, which is the reason for permit and plancheck requirements.

 

[buddyboy]

It doesn't matter if God himself comes down and blesses your work.

you've already said that the work in that building is already pretty shoddy, but shoddy or not if it was permited and inspected it'll be ok in a court room.

anyone and everyone that did work in there without a permit or inspection is gonna get blamed.

that's just the way it works

why are you willing to risk loosing everything over "To be honest, the wiring work that has been done in this building is shoddy, to say the least."

that's gonna be all on you.