Another 100 amp panel thread

[Nick in WI]

Hey guys, I'm in the planning stages of my shop build and am now figuring out the electrical. I'm trying to do the research but just get more confused the more I read. I currently have 200 amp service in my house and the run to the sub panel of the proposed shop will be about 250'. I'm not dead set on 100 amps and would by fine with 80 or 90 amps since with such a long run a small jump in cost per foot can be a large amount overall. I'm not opposed to aluminum as I see no reason to stress it considering my current main supply lines are already aluminum.

What's the most economical option in my situation?

Thanks!!

 

[wyliesdiesels]

well you should start by listing your loads, number of people working concurrently, etc

 

[Nick in WI]

well you should start by listing your loads, number of people working concurrently, etc

Thanks for the comment. I have a large compressor that is I believe 25 amps and I currently own a 30 amp welder but will likely invest in a larger 40-50 amp welder at some point. I will be running a 2 post lift which will be 20-25 amps. Tire balancer that is under 20 amps. Besides that just misc hand tools and other small loads. But it is just me and I wouldn't ever expect to have more than maybe one other person working in the shop.

 

[Bretny]

It sounds like 100a is what you need. I could see the lift, compressor and balancer going all at once. Extra power is really expensive late down the road.

 

[Nick in WI]

It sounds like 100a is what you need. I could see the lift, compressor and balancer going all at once. Extra power is really expensive late down the road.

That's very true. I've continued my research despite my ignorance.

Would 2/0-2/0-1-4 Aluminum Mobile Home Feeder work?

Something like this: https://www.amazon.com/gp/product/B07FNFYQYT/?tag=atomicindus08-20

If I were to go with that what is the conduit requirements? Does it need conduit in the basement (from main panel to the exit)? I know it will need conduit where it comes out of the ground but I don't think it needs it in the ground, although I'd probably still use conduit.

 

[Falcon67]

I'll offer this (as done previously for these Qs LOL) - my run is 130'. Shop is 24x40, includes 2 AC units total 18K BTU, 5000w 230v heater, 3.5 HP 230V compressor, 3/4 HP well pump, welder, 230v 2hp lathe, 230v 1 hp mill, 120v lathe, drill press, 230v lift, 230v 50A RV plug for race trailer, misc other power tools, lots of lights. Head end fused at 70A, no trips in 7 years.

 

[Nick in WI]

I'll offer this (as done previously for these Qs LOL) - my run is 130'. Shop is 24x40, includes 2 AC units total 18K BTU, 5000w 230v heater, 3.5 HP 230V compressor, 3/4 HP well pump, welder, 230v 2hp lathe, 230v 1 hp mill, 120v lathe, drill press, 230v lift, 230v 50A RV plug for race trailer, misc other power tools, lots of lights. Head end fused at 70A, no trips in 7 years.

That's good to know, although I don't have all of that equipment yet it sounds like our shop uses are similar. I really don't think that I need 100 amps, I can't see having any issue with 70-90 but I guess it all depends on where the guage breaks are for a 250' run. If the economical wire choice for 70 amps will also carry 90 or a 100 I'd obviously go with a larger breaker in the main panel. Being only 1 guy I can only do so much at one time so my expected max load would be air compressor, welder, lights and maybe boiler circulating pump.

I don't ever plan to have any significant climate control load. AC is completely unnecessary here and heat will be a gas boiler so very little electrical load there.

 

[sberry]

The smaller welder and the air comp could live on a 60A breaker. If you have a larger welder a guy could stop welding if the comp came come or let it finish a cycle before welding. Number 2 alum is the cheapest, good for 90A but not at that distance. I have several that long and use a 60 on them, never had one trip and ran a welding shop on it one winter.

 

[Nick in WI]

The smaller welder and the air comp could live on a 60A breaker. If you have a larger welder a guy could stop welding if the comp came come or let it finish a cycle before welding. Number 2 alum is the cheapest, good for 90A but not at that distance. I have several that long and use a 60 on them, never had one trip and ran a welding shop on it one winter.

So you're saying 2-2-2-4 Aluminum Mobile Home Feeder could be served by a 60 amp breaker? I doubt I would ever exceed that but I plan to use this shop for decades so I'd like to future proof if the cost isn't too drastic.

Using Amazon prices:

2-2-2-4 Aluminum Mobile Home Feeder is $387 for 250'

2/0-2/0-1-4 Aluminum Mobile Home Feeder is $520 for 250'

If those were my options I'd probably spring for the extra $133 for an extra 40 amps even though they'll likely never be needed. I'm not sure though if the 2/0 is sufficient for 100 amp.

 

[Bretny]

I think you should be looking at acceptable voltage loss at 250f along with amps.

 

[Falcon67]

So you're saying 2-2-2-4 Aluminum Mobile Home Feeder could be served by a 60 amp breaker? I doubt I would ever exceed that but I plan to use this shop for decades so I'd like to future proof if the cost isn't too drastic.

I use 2-2-2-4 on my run and it's good for up to 90A at the 130' distance. I used a 70A head end breaker because that's what HD had on the shelf.

 

[Nick in WI]

I think you should be looking at acceptable voltage loss at 250f along with amps.

I have no idea how to calculate that. If you were in my position what would be your go to solution?

Also I do have to run it about 30' inside the basement to the panel (that is included in the 250' estimate)?? My understanding is that MHF would need to be run in conduit inside but if I changed over to SER cable just outside the foundation wall I could run that in the basement with no conduit. That would greatly reduce the number of bends in the conduit making the pull much easier but maybe the cost of the splices and box would be too much?

 

[wyliesdiesels]

That's very true. I've continued my research despite my ignorance.

Would 2/0-2/0-1-4 Aluminum Mobile Home Feeder work?

Something like this: https://www.amazon.com/gp/product/B07FNFYQYT/?tag=atomicindus08-20

If I were to go with that what is the conduit requirements? Does it need conduit in the basement (from main panel to the exit)? I know it will need conduit where it comes out of the ground but I don't think it needs it in the ground, although I'd probably still use conduit.

MHF does not have an outer jacket so it will need to be in conduit when inside.

It can be direct buried however conduit underground is highly recommended. it is cheap insurance.

I have no idea how to calculate that. If you were in my position what would be your go to solution?

Also I do have to run it about 30' inside the basement to the panel (that is included in the 250' estimate)?? My understanding is that MHF would need to be run in conduit inside but if I changed over to SER cable just outside the foundation wall I could run that in the basement with no conduit. That would greatly reduce the number of bends in the conduit making the pull much easier but maybe the cost of the splices and box would be too much?

At 250', to keep voltage drop below 3% with #2 al, you should not have more than 50a continuous load. With the compressor and welder possibly running at same time, you could definitely exceed this.

heres the math: (((0.3ohms/1000)*(250'*2))*50a)/240v=.03125*100 = 3.125%

*.3 is resistance of #2 al per 1000' found in table 9 of chap 9 in NEC
*250' is length
*50 is amps/current

So i would go with the larger MHF cable.

And yes you can transition to SER so that you dont need conduit indoors.

 

[Nick in WI]

MHF does not have an outer jacket so it will need to be in conduit when inside.

It can be direct buried however conduit underground is highly recommended. it is cheap insurance.



At 250', to keep voltage drop below 3% with #2 al, you should not have more than 50a continuous load. With the compressor and welder possibly running at same time, you could definitely exceed this.

heres the math: (((0.3ohms/1000)*(250'*2))*50')/240v=.03125 - 3.125%

*.3 is resistance of #2 al per 1000' found in table 9 of chap 9 in NEC
*250' is length
*50 is amps/current

So i would go with the larger MHF cable.

And yes you can transition to SER so that you dont need conduit indoors.

Thanks for your help!!

So right now my thought is 2/0-2/0-1-4 Aluminum Mobile Home Feeder from a junction box at the house foundation to the subpanel inside 2 inch pvc conduit. Then 2/0-2/0-2/0-1 (it's what I found online) from the junction box into the basement and over to the main panel with a 100 amp breaker.

I'm figuring:

$520 for 250' of 2/0-2/0-1-4 Aluminum Mobile Home Feeder from Amazon
$120 (with shipping) 2/0-2/0-2/0-1 SER from wireandcableyourway.com
$200ish conduit
$60ish for junction box and connectors

In the junction box is it safe to use the following connector wrapped heavily in electrical tape to go from MHF to SER?
https://www.homedepot.com/p/NSi-Ind...hanical-Connector-2-0-14-AWG-2-2-0T/306824009

 

[sberry]

The extra cost for bigger wire isn't a deal breaker. As for voltage drop and percentages,,,, I could never tell from using tools there was a sag. Mine is hot, lots of them are closer to 250 today than 240, could drop 10 percent and still be near 230, could tolerate 20 volts drop and that's only relevant when running simultaneous loads which is and can be very minor.
By the math is is 50, in use it doesn't know if it has a 50 or 60 on it, I use a 60 on 2 as its the cheapest large breaker and leaves a little more headroom for motor starts.
By the way, welding isn't continuous, neither is air comp or any of those other tools excepting for some lights and many today are insignificant with LED.

 

[wyliesdiesels]

Thanks for your help!!

So right now my thought is 2/0-2/0-1-4 Aluminum Mobile Home Feeder from a junction box at the house foundation to the subpanel inside 2 inch pvc conduit. Then 2/0-2/0-2/0-1 (it's what I found online) from the junction box into the basement and over to the main panel with a 100 amp breaker.

I'm figuring:

$520 for 250' of 2/0-2/0-1-4 Aluminum Mobile Home Feeder from Amazon
$120 (with shipping) 2/0-2/0-2/0-1 SER from wireandcableyourway.com
$200ish conduit
$60ish for junction box and connectors

In the junction box is it safe to use the following connector wrapped heavily in electrical tape to go from MHF to SER?
https://www.homedepot.com/p/NSi-Ind...hanical-Connector-2-0-14-AWG-2-2-0T/306824009

I would not use those.

Instead use split bolts or polaris connectors.

https://www.homedepot.com/p/Polaris-3-0-6-AWG-Insulated-Tap-Connector-Black-IT-3-0B/303578434

 

[Marctrees]

The polaris are nice, but $ wise.. I recently got , sized for my 100a job, splitbolts for local Elect supply house for $6 each.

Sure, gotta buy and spend time w tape.. but I have more time than money.

And, I really get a good satisfaction of the ..in my mind, super good connection of split bolts.

Marc

 

[Nick in WI]

I would not use those.

Instead use split bolts or polaris connectors.

https://www.homedepot.com/p/Polaris-3-0-6-AWG-Insulated-Tap-Connector-Black-IT-3-0B/303578434

Thanks for the warning I saw the Polaris connectors while researching but at $28 a piece I was a little deterred. I'll probably go with aluminum split bolts which I found for $14ish.

Thanks again for your help in figuring this all out.

 

[Nick in WI]

The polaris are nice, but $ wise.. I recently got , sized for my 100a job, splitbolts for local Elect supply house for $6 each.

Sure, gotta buy and spend time w tape.. but I have more time than money.

And, I really get a good satisfaction of the ..in my mind, super good connection of split bolts.

Marc

I definitely agree, the polaris price scared me off. I'll have to check with the local supply houses but I did find some aluminum split bolts on amazon for $14 which seems reasonable.

 

[Marctrees]

$14 for a single one is wayy too high.

I'm an amazon regular,,,

Be aware alot of small $ stuff is way overpriced.

The cost of convenience, often worth it, but be aware.

Styptic pencil I needed for dog nail trimming..

about $6 at Amazon,

EXACT same one at Wally for about $1.30

I was going to Wally anyway, so saved the couple bucks.

Marc

 

[Marctrees]

*********** And, don't forget the NoAlox ***********

It rubs the NoAlox into the wire, or it gets the Hose.

Marc

 

[Marctrees]

I am sure ... especcially w the amount of wire you will be buying you will check pricing.

Make sure you call all local "Wholesale" Electrical Supply houses..

Tell them "Cash sale, no account, need the following..........."

Talk like a Pro... NO sloppy terminology.

Don't call it "Waaar" unless you live in extreme SE.

No stupid questions...

Get those all answered beforehand.

Have it ALLLL figured out before you call them.

Many of the Countermen do NOT like to deal w non Pros, and will give a shallower discount price the sillier you are.

That's just how it often is.

Then, in a serious voice... ask if there is any further discount available.

Probably not, but it costs nothing to ask.

Marc

 

[Nick in WI]

$14 for a single one is wayy too high.

I'm an amazon regular,,,

Be aware alot of small $ stuff is way overpriced.

The cost of convenience, often worth it, but be aware.

Styptic pencil I needed for dog nail trimming..

about $6 at Amazon,

EXACT same one at Wally for about $1.30

I was going to Wally anyway, so saved the couple bucks.

Marc

Good call, your post inspired me to keep digging and I found that Menards offers them for $10. Might be able to do better yet with some more digging. Thanks marc

 

[Marctrees]

"Prime" , with "Free" shipping, often, not always, but often carries a premium price.

Looking at beeper water levels tonight.

At rough quick glance, A Prime is $45, Lowes is $38.

Just an example.

Compare the options, convenience is often good, but never free.

Also funny thing...

Got 100 a CU cut to lengths waaar, and some little stuff for 100 a sub few months ago...

EVERYTHING was better priced on no acct from Supply house..

Cept, WTH...

They nailed me about $8 for a roll of Scotch 88..

About $4 at Lowes.

No bitching, was great service overall.

Anomolys will happen.

Marc

 

[Marctrees]

Course, $7 for delivery to my door is awesome, the water level price diff, if I don't need to go to Lowes for other more stuff.

And in my case, in the woods, it's 35 miles one way.

So, I do alot of Amazon

But I'm aware.


Marc

 

[mike93lx]

*********** And, don't forget the NoAlox ***********

It rubs the NoAlox into the wire, or it gets the Hose.

Marc

Dude, you are posting like sberry lately...


Noalox ie only required if the wire manufacturer specs it (per posta i've seen here by the sparkys)

 

[Norcal]

Dude, you are posting like sberry lately...


Noalox ie only required if the wire manufacturer specs it (per posta i've seen here by the sparkys)

It’s required if the equipment manufacturer requires it but that being said, I use it.

 

[nsula_country]

Dude, you are posting like sberry lately...


Noalox ie only required if the wire manufacturer specs it (per posta i've seen here by the sparkys)

I use it exclusively on ALL aluminum wire connections... Don't want to get the hose again!

CT