New service or sub panel advice needed

[ururk]

Good news. I was able to talk with him today. He was saying I'd have to use 2-2-2-6 cable because that's all that they stock around here - and I can verify, at least the few places I checked with, that nothing else - in combination - is available. He wasn't sure how I planned to install it, but was thinking I'd use a cable, and not individual conductors.

Additionally, he just want's photos of the conduit ends with a tape measure, or a pipe in the ground ending at the pipe that he can measure from.

He also said he uses the 90C column - in fact a supply house person I spoke with today said that was what they typically use around here.

 

[mike93lx]

Good news. I was able to talk with him today. He was saying I'd have to use 2-2-2-6 cable because that's all that they stock around here - and I can verify, at least the few places I checked with, that nothing else - in combination - is available. He wasn't sure how I planned to install it, but was thinking I'd use a cable, and not individual conductors.

Additionally, he just want's photos of the conduit ends with a tape measure, or a pipe in the ground ending at the pipe that he can measure from.

He also said he uses the 90C column - in fact a supply house person I spoke with today said that was what they typically use around here.

OK, great, so they are at least consistently wrong.

Do what you want, but that isn't right.

 

[ururk]

OK, great, so they are at least consistently wrong.

Do what you want, but that isn't right.

Are you referring to which column to use?

I’m using the 75C column, not the 90C that he said to use. As for the wire gauge - I’m pretty sure he’d make me put a 90A breaker in if I used #2 AL. He didn’t read the question I emailed, he was really just saying I’d have to use what I could get locally and breaker to the allowable ampacity.

In fact, the guy at the supply house, this one gave me a sad laugh. I asked for prices on #3 cu / #1 AL. He said, for 100A? You only need #2. And I asked where in the NEC did it said that, and he said to use the 90C column. I protested and he went on to say “Oh yeah, people around here use 90C for residential, 75C for commercial”. I mentioned breaker ratings - he dismissed them as “oh those don’t mean much”. I didn’t even bother asking where in the NEC it differentiated residential from commercial when observing conductor ratings.

Please understand - I’m just writing this because I’m HORRIFIED at what these people are telling me. At least I’m doing research, trying to understand what is code, why, and following it or slightly better. I presume if he tells me #2 aluminum and I use #1 he cannot fault me (unless I don’t size up my ground as well).

At the moment I’m waiting on conduit to arrive, the load center I ordered, and getting the basement ceiling tiles taken off.

 

[mike93lx]

Absolutely good on you for doing research. It sounds like you need it as you are getting bad info from the guy at the supply house.

Based on info here, you know what needs to be done if you want 100a. Just need to decide if it is worth it.

 

[ururk]

Installing ground rods - some advice.

I bought two 8', 5/8" copper clad ground rods from Menards the other day. I've seen posts on GJ, and videos on YouTube demonstrating techniques to install these:

1) water method
2) Hammer Drill attachment (pound top)
3) Hammer Drill attachment (plate with a hole, grips the bottom of the rod and pounds it in)
4) Air-compressor attachment with some sort of rotary hammer

For someone who has none of the tools (except an air compressor), which should I attempt? I worry #1 won't provide proper conductivity with the ground. I can rent a hammer drill, but then I have to purchase the bit - would like to keep costs low.

Additionally, am I correct:

The ground rod and wire can be buried below the ground
The #6 conductor does not need to be sleeved
The conductor should be continuous in length (unbroken)
The conductor can be solid or stranded (I bought solid)

 

[brewchief]

Installing ground rods - some advice.

I bought two 8', 5/8" copper clad ground rods from Menards the other day. I've seen posts on GJ, and videos on YouTube demonstrating techniques to install these:

1) water method
2) Hammer Drill attachment (pound top)
3) Hammer Drill attachment (plate with a hole, grips the bottom of the rod and pounds it in)
4) Air-compressor attachment with some sort of rotary hammer

For someone who has none of the tools (except an air compressor), which should I attempt? I worry #1 won't provide proper conductivity with the ground. I can rent a hammer drill, but then I have to purchase the bit - would like to keep costs low.

Additionally, am I correct:

The ground rod and wire can be buried below the ground
The #6 conductor does not need to be sleeved
The conductor should be continuous in length (unbroken)
The conductor can be solid or stranded (I bought solid)

What's your soil like? I've had rods that you could push down close to halfway and then drive the rest of the way with a small sledgehammer.

I wouldn't spend a dime on anything until I tried driving them down with a hammer, it's a good idea to slide the ground clamp onto the rod so if you mushroom the end a bit you don't have to try to clean it up, inspector probably won't like it if it looks like it was cut off.

Sent from my SM-G965U using Tapatalk

 

[ururk]

What's your soil like? I've had rods that you could push down close to halfway and then drive the rest of the way with a small sledgehammer.

I wouldn't spend a dime on anything until I tried driving them down with a hammer, it's a good idea to slide the ground clamp onto the rod so if you mushroom the end a bit you don't have to try to clean it up, inspector probably won't like it if it looks like it was cut off.

Soil? More like loamy clay, with a bit of gravel put in.

I'll try pounding it in, if that doesn't work I can borrow a metal fence post driver from a friend.

 

[mike93lx]

If you want an excuse, it would be a great time to buy a rotary hammer...something like a Bosch bulldog. Unbelievably useful if you ever have to demo tile, drill a bunch of holes in concrete or drive ground rods.

I love mine and wish I bought it sooner

 

[ururk]

If you want an excuse, it would be a great time to buy a rotary hammer...something like a Bosch bulldog. Unbelievably useful if you ever have to demo tile, drill a bunch of holes in concrete or drive ground rods.

I love mine and wish I bought it sooner

Oh trust me, I've been searching for a reason. It's just... I really would use it once. And there are too many variations (the ones that Bosch makes), not sure which I would find most useful.

 

[mike93lx]

Oh trust me, I've been searching for a reason. It's just... I really would use it once. And there are too many variations (the ones that Bosch makes), not sure which I would find most useful.

You'll find more uses...

I got the SDS plus model for about $180. I tend to buy corded for a toll like that which will see infrequent usage as I expect to have it through a likely cordless tool change.

 

[ururk]

Well, I will eventually have to core drill some concrete...

 

[wyliesdiesels]

I just bought a 1” sds milwaukee cordless drill with an 8x battery.

This thing is awesome. Kicks ***!!

 

[Bert_]

I have a Bosch rotary hammer and the ground rod attachment. Hardly ever use it. Just as fast to use a hand driver and it's less **** to drag around.

A post pounder works great until you get to the last two foot. But you can just flip it over if you have a decent aim and is something most people already have.

 

[ururk]

Got it! I'm pricing out rotary drill rentals vs refurb/used/eBay. I have to core through the concrete over at the house. Right now it's looking like $200 for a SDS unit capable of the core I need VS $118/day for the rental ($80 half day!). That didn't include core "bits" in the rental price. If it ends up making sense to buy the drill then I'll first try chucking the ground rod in a chuck attachment. Some say that works.

 

[mike93lx]

I have a Bosch rotary hammer and the ground rod attachment. Hardly ever use it. Just as fast to use a hand driver and it's less **** to drag around.

A post pounder works great until you get to the last two foot. But you can just flip it over if you have a decent aim and is something most people already have.

Sure, maybe in Iowa. In New England, you would use it every time.

 

[mike93lx]

Got it! I'm pricing out rotary drill rentals vs refurb/used/eBay. I have to core through the concrete over at the house. Right now it's looking like $200 for a SDS unit capable of the core I need VS $118/day for the rental ($80 half day!). That didn't include core "bits" in the rental price. If it ends up making sense to buy the drill then I'll first try chucking the ground rod in a chuck attachment. Some say that works.

Yes, many drive rods directly in the chuck. I don't love the idea, but if I just had two to drive, I might do the same, although you can get a bit for about $20 on amazon

 

[ururk]

I opened up the electrical panel at the house to take a peek:

It's kind of a mess. Anything I should do before getting the project inspected? I feel like there is a lot of excess wire on the bottom that could be shortened. I did not install the generator transfer switch, but I did FIX the wiring on the transfer switch as the "electrician" who wired it up wired it wrong. And yes, it was a paid electrician. I'm still uneasy about this thing, even though I used the manual to re-connect it properly. I've tested to make sure it doesn't backfeed into the line, but don't trust my multimeter tests.

Also - based on where things are located - I want to bring my wires into this panel through the TOP RIGHT-SIDE (just above the transformer). Should I shift all the breakers on the right side down two positions, leaving the top 50A breaker in place? Can I leave the neutrals in place or would I want to shift those down as well? Moving breakers seems like a safe task, and would reduce the amount of cable by 2 feet.

 

[jeffmoss26]

yikes

 

[mike93lx]

I would do the minimum necessary to clean it up and get your new breaker in. I like pretty panels, but is it worth several hours?

 

[ururk]

There are a few things I must do - the wires at the bottom pop out when the cover is removed, that needs a zip tie. Shortening them could also help. Not sure I really want to commit to too much work otherwise - specifically I don't want to start loosening screws.

I would like to move the breakers down two slots, though - any concerns there? House was built in 84, most of the breakers are original with a few exceptions.

Also... the house only has a single ground rod. Wondering if the inspector will have me add a second... probably not. But is it a good idea?

 

[ururk]

Well, I got the 1-1/4" EMT connected to the panel:

I can't link to the second photo, but it just shows the 90 degree fitting. With two additional 45 degree turns this makes 360 degrees, not happy about this but it is allowed.

https://www.instagram.com/p/CARBL-QJXJ5/

And yes - the "header" over that door is sort of missing any sense of support. I'll be adding some blocking, this was just all I could get to the other night.

 

[bad_idea]

I am not an electrician, so take what I say for what you paid for it. I like to have extra cable in the box incase you have a bad connection that burns up the end of the cable. You can then cut back the bad end and re-terminate the cable. For that same reason I would come in the top of the box with your wire and run it down to the available breakers. Then, if you have a fault later on you can move the breaker up and shorten the cable.

 

[ururk]

I am not an electrician, so take what I say for what you paid for it. I like to have extra cable in the box incase you have a bad connection that burns up the end of the cable. You can then cut back the bad end and re-terminate the cable. For that same reason I would come in the top of the box with your wire and run it down to the available breakers. Then, if you have a fault later on you can move the breaker up and shorten the cable.

I like this idea - and yes I'm coming in from the top.

At the same token - how likely is a bad connection if I tighten the breakers to spec? Does this happen?

 

[ururk]

Rather than cross-post I updated my main build thread:

https://www.garagejournal.com/forum/showpost.php?p=8529091&postcount=673

Probably will post progress updates there, and any questions here if no one objects .

 

[ururk]

Quick ground rod & conductor question...

I bought two copper clad 5/8" ground rods, have 25' of copper #6 on hand. I also purchased cadweld one-shot for both rods.

For the rods themselves - I can bury the tops of the rods below the earth, right? I have leftover PVC tube so I plan to cut that to 6" or so and when I backfill the hole I dig, leave them exposed so the inspector can see them.Our house rod sticks out about 12".


For the #6 conductor, I installed a small conduit:

Do I cut this conduit at the concrete, or do I run it up to the load center?

Thanks!

 

[ururk]

Let me be the first to say there is no way I could have installed those ground rods without the hammer drill.

I was able to push the first rod in about 3', and then it wouldn't budge. The other rod I got in maybe 6". The soil might have been water-saturated on the first one, the second was in undisturbed clay. Ended up buying the special tool ($20) to install the rod, worth every penny.

Anyhow - I'm not very heavy - maybe 140 - and running the drill at its maximum speed, more or less putting all my weight on the drill, and it moved s-l-o-w-l-y into the ground. There was a point where I through it might not go in anymore.

Also, I used cadweld one-shot connectors to bond the ground wire to the rods. Neat process!

 

[nadogail]

Reading all this discussion has added to my education.

Thanks to everyone for posting.

 

[ururk]

Speaking of education got a few questions... code-related...

1) Do I need to attach the conduit to the concrete foundation with a bracket? Or is the ground considered a support? The distance to ground from the LB is less than 3'. Should I whether or not it is required by code?

2) How do I calculate my grounding conductor for the feed to the barn? I did some "retail research" and find 2-2-2-4 AL and 3-3-3-5 CU cables are available - this tells me these are probably "correct" combinations of the gauges. I'm pricing out both options as individual conductors.

 

[wyliesdiesels]

The size of the ground wire is dependent on the feeding breaker size.

For up to 100a breaker you only need #6...

See table 250.122

 

[mike93lx]

I don't know what code would require, but I would come straight up, use and expansion coupling and go right into the LB.

Why not just run 2-2-2-4 AL? MHF will come all bundled and ready to pull without having to pull out separate lengths from a spool. Plus the MHF will have the neutral and ground identified already

 

[ururk]

I'm not sure code allows MHF in conduit (well, from what I was reading the cross-sectional area might be too big for certain conduit sizes)? Or if it will be easy to pull? I'll price it out too.

I can get individual conductors in a variety of colors, so running individual ones won't be much of an issue. I figured this would reduce the total weight of wire I have to move around, and since they will be individually spooled, I can just make a feeding rack.


As for the expansion coupling... I wasn't planning on using one - I did the calculations and came up with just under .25":

x=40", y=(3.38*10^-5)*(150)*(x)

(-10 to 110F, + 30F since some is in sunlight)

Expansion amount: 0.2028" - under the required 0.25". This assumes the entire 40" run is in the sun, and only 20" will be. When I take 20" above and 20" below into account:

x=20, y=(3.38*10^-5)*(150)*(x)+(3.38*10^-5)*(120)*(x)

Expansion amount: 0.18252"

Our meter is much higher up on the wall, and does not have an expansion coupling.

 

[ururk]

The size of the ground wire is dependent on the feeding breaker size.

For up to 100a breaker you only need #6...

See table 250.122

Thanks!

 

[mike93lx]

I'm not sure code allows MHF in conduit (well, from what I was reading the cross-sectional area might be too big for certain conduit sizes)? Or if it will be easy to pull? I'll price it out too.

I can get individual conductors in a variety of colors, so running individual ones won't be much of an issue. I figured this would reduce the total weight of wire I have to move around, and since they will be individually spooled, I can just make a feeding rack.


As for the expansion coupling... I wasn't planning on using one - I did the calculations and came up with just under .25":

x=40", y=(3.38*10^-5)*(150)*(x)

(-10 to 110F, + 30F since some is in sunlight)

Expansion amount: 0.2028" - under the required 0.25". This assumes the entire 40" run is in the sun, and only 20" will be. When I take 20" above and 20" below into account:

x=20, y=(3.38*10^-5)*(150)*(x)+(3.38*10^-5)*(120)*(x)

Expansion amount: 0.18252"

Our meter is much higher up on the wall, and does not have an expansion coupling.

MHF is fine in conduit. Xhhw will be easier to pull

 

[wyliesdiesels]

I'm not sure code allows MHF in conduit (well, from what I was reading the cross-sectional area might be too big for certain conduit sizes)? Or if it will be easy to pull? I'll price it out too.

I can get individual conductors in a variety of colors, so running individual ones won't be much of an issue. I figured this would reduce the total weight of wire I have to move around, and since they will be individually spooled, I can just make a feeding rack.


As for the expansion coupling... I wasn't planning on using one - I did the calculations and came up with just under .25":

x=40", y=(3.38*10^-5)*(150)*(x)

(-10 to 110F, + 30F since some is in sunlight)

Expansion amount: 0.2028" - under the required 0.25". This assumes the entire 40" run is in the sun, and only 20" will be. When I take 20" above and 20" below into account:

x=20, y=(3.38*10^-5)*(150)*(x)+(3.38*10^-5)*(120)*(x)

Expansion amount: 0.18252"

Our meter is much higher up on the wall, and does not have an expansion coupling.

There is no code prohibition on MHF in conduit

 

[ururk]

All right... I decided to buy the expansion fittings. For one, I'm getting real close to the cutoff of allowed movement, and two, as I was watching some YouTube videos there was mention of frost heave. Being where I am, for $14/expansion coupler, it's worth the peace of mind and it isn't worth the pain of asking the inspector whether he'll require them or not. Rather than spend days worrying about this, researching soil expansion and theoretical soil calculations I'm just going to do it.

 

[mike93lx]

All right... I decided to buy the expansion fittings. For one, I'm getting real close to the cutoff of allowed movement, and two, as I was watching some YouTube videos there was mention of frost heave. Being where I am, for $14/expansion coupler, it's worth the peace of mind and it isn't worth the pain of asking the inspector whether he'll require them or not. Rather than spend days worrying about this, researching soil expansion and theoretical soil calculations I'm just going to do it.

Frost is why I said I would install one

 

[ururk]

A few other questions that keep cropping up...

1) I've read through Mike Holt's forum, watched some of his videos. There is a requirement for a bonded bushing for EMT entering a cabinet with concentric/eccentric punchouts - when the voltage is higher than 250V (NEC. Section 250.97).

I'm a belt+suspenders sort of person - and ran 1-1/4" EMT from my electrical panel to the outside of the house. It enters the electrical cabinet through - a concentric punchout. It uses a standard locknut, I don't believe it is a grounding locknut.

I plan to install a grounding bushing because it seems like a smart thing to do, as opposed to just an insulated bushing. I really don't want to call the inspector to ask - could I be dinged for doing something that is not required since it's a 240 circuit? To me it feels like a reasonable thing to add.

2) The panel I purchased can be installed upside-down for a bottom-feed situation (which I have). On YouTube I see a LOT of people installing panels "upright" and running the conductors all the way to the top and looping them around. What's up with this? I know rotating the panel will make things a bit confusing - the numbers on the bus bar are now upside-down - but it seems like a good thing to reduce the total wire run length by 4'. Thoughts?

 

[Bert_]

A few other questions that keep cropping up...

1) I've read through Mike Holt's forum, watched some of his videos. There is a requirement for a bonded bushing for EMT entering a cabinet with concentric/eccentric punchouts - when the voltage is higher than 250V (NEC. Section 250.97).

I'm a belt+suspenders sort of person - and ran 1-1/4" EMT from my electrical panel to the outside of the house. It enters the electrical cabinet through - a concentric punchout. It uses a standard locknut, I don't believe it is a grounding locknut.

I plan to install a grounding bushing because it seems like a smart thing to do, as opposed to just an insulated bushing. I really don't want to call the inspector to ask - could I be dinged for doing something that is not required since it's a 240 circuit? To me it feels like a reasonable thing to add.

2) The panel I purchased can be installed upside-down for a bottom-feed situation (which I have). On YouTube I see a LOT of people installing panels "upright" and running the conductors all the way to the top and looping them around. What's up with this? I know rotating the panel will make things a bit confusing - the numbers on the bus bar are now upside-down - but it seems like a good thing to reduce the total wire run length by 4'. Thoughts?

Most panels are designed to be rotated. The text will either be written both way or written sideways.

 

[u2slow]

EMT is typically installed without any bushings if cast aluminum connectors are used. If you are pulling a bond/EGC wire, there's even less need for the bond/EGC bushing.

My biggest consideration for panel orientation is what direction most of the branch circuits will enter from... so I can utilize the panel end with the most smaller knockouts.

 

[ururk]

EMT is typically installed without any bushings if cast aluminum connectors are used. If you are pulling a bond/EGC wire, there's even less need for the bond/EGC bushing.

My biggest consideration for panel orientation is what direction most of the branch circuits will enter from... so I can utilize the panel end with the most smaller knockouts.

I believe it is cast aluminum, will check.

As for the panel - I think it’s symmetrical, but will review the datasheet before I make a decision.