Electric panel questions.

[Perry]

I didn't want to derail the "Garage heater install" thread so I've started a new one.

Some of you have probably been thru this and may have answers or info to share.

My house is an older house from around 1940. Small panel with the meter inside the house. The insurance company uses this excuse to justify their high policy premiums.

I've built a new 24' x 24' garage and it will be needing power. So the plan was to install a new panel in the garage and feed a sub panel to power the house. (The insurance company will need another excuse.)

The estimator was here today. Just thinking over what we talked about and I think I remember him saying the feeder from the garage to the house panel will be aluminum.
Reading on the web it says it can be either copper or aluminum. Pros? Cons?

Also he suggested a 100 amp service in the garage. If you go larger you need to contact Enmax to confirm that the transformer in your area has enough capacity to go with a larger service. Enmax has confirmed I am good for 200 amps? What do I need? I could see a possible electrical vehicle charger down the line. I'm into machining as a hobby and presently work on smaller items but you all know how that goes. (Maybe I'll find a $500 milling machine locally that needs 9'X9'X10' of space. lol )

The panel I have now for the house has six screw in fuses. (90 amp? 6 fuses X15 amp? I'm guessing here.) The dryer and stove are gas . Gas furnace. No other big loads.

Thoughts on panel size?


Just to add to the story , seeing I was digging a trench for the electrical I decided that I might as well run the gas line at the same time. When my friend did his electrical it was a 4" wide trench 20" deep. I was expecting the same. My trench needs to be 18" wide 20" down. The gas and electrical need 12" of seperation.

Haven't got the actual cost of this yet, but I'm sure it won't be cheap.

 

[Chip Maker]

200 amp panel with 100 amp sub would be my suggestion.

 

[Brent H]

@Perry : Go 200 amp on the shop and then feed a 125 amp panel in the house.

Aluminum is fine and will be cheaper than the copper. When you install the aluminum conductors you coat the ends with a paste to prevent Oxidation and be sure to torque the clamp screws to the required spec. This is typically listed in the panel box/ The panel box should also have a sticker in it that says it is CU/AL compatible.

The whole Aluminum issue was in the 70's 80's where people were just installing regular receptacles in their homes with AL wiring. the AL would expand and contract with the heat during use and work the screws loose resulting in arcing and fires. To solve this they required a pigtail of copper conductor be added to the end of the AL wiring using a special crimp/wire nut. Now you can just use the AL as a feeder to panels and meter bases. My main 200 amp service from the street to the meter is AL.

If you run gas to your shop you can install a simple radiant floor heating system if you want to go crazy

You also need to put mechanical protection above the run lines and caution tape. The gas line also requires a copper trace wire.

 

[kylemp]

I'd agree with everyone else. In my shop it's exactly that, 200a in, 100 goes to the house. That leaves enough to have 6x 50a outlets and enough power to be milling or plasma cutting and have the compressor running. It's not a huge increase in cost to do it now, but doing it later would be a substantial cost.
As for the AL wire, I'm quite sure it isn't an issue and I believe Brent to be correct in what he says, but I'm not a sparky so having a professional opinion is valuable. Given that we all know about the concerns of aluminum wire, you can bet that new builds wouldn't be allowed it if the potential for fire was still there.. It's really the old houses that are the concern. For feed lines as far as I'm aware it's just fine.
Another thing that I've seen in industrial that I plan on doing when I build is running oversized conduit with fish lines inside so you can modify things later, you could do the same with your supply to the house in the event you needed to change at a later date but it's not likely.

 

[cuslog]

I had mine done last year (Calgary). 1975 vintage house W/100 amp service. My first thought was to have Enmax bring a new 200 amp service (under ground)to the garage. While possible, they gave a rough estimate of $10 ~ 15 K to bring 200 Amp service across the alley, to the property line. I dropped that idea like a hot potato !
Electrician suggested a new panel (100A) in the house with a sub (90A) to the Garage. Did the gas at the same time - I dug the trench (they wanted $600 to do it). I would have said 20" wide x 18" deep but maybe I'm wrong. Aluminum wire panel to panel, all other copper. On the 90A garage panel he put in 5 X 240 circuits (3 @ 50A and 2 @ 20A) ( one was just rough in for possible EV charger) also 4 or 5 120V x 20A circuits.

 

[Johnwa]

In Calgary I believe the main panel has to be done by a licensed electrician, The home owner can do sub panels though. As a DIYer I won’t touch aluminum, copper is way more forgiving.

 

[trlvn]

On the 90A garage panel he put in 5 X 240 circuits (3 @ 50A and 2 @ 20A) ( one was just rough in for possible EV charger) also 4 or 5 120V x 20A circuits.

I was reading that home charging stations for Tesla vehicles can use up to 80 amps at 240 volts. What capacity did you rough in for your garage?

Craig

 

[cuslog]

I don't think the wire they installed would take 80 Amps, without going out there to verify, I'd say its probably 12 ga. I just relied on sparky to put in suitably sized wire. So maybe a Tesla isn't in my future ? He did say some are just 110V ? Welder plug is nearby though, that's 6 ga. IIRC.

 

[trlvn]

I don't think the wire they installed would take 80 Amps, without going out there to verify, I'd say its probably 12 ga. I just relied on sparky to put in suitably sized wire. So maybe a Tesla isn't in my future ? He did say some are just 110V ? Welder plug is nearby though, that's 6 ga. IIRC.

I was shocked at the 80 amp reference. (Haha, "shocked"!) They call it "trickle charging" if connected to a 120 volt circuit. Apparently it adds 2 or 3 miles of range per hour of charging at that level. The 80A @ 240V is called Level 2 and will fully charge the vehicle in ~6 hours, IIRC. The Tesla Supercharger stations are apparently a 480V connection.

Even if the vehicle is only charged at Off-peak rates, that must add a very significant kick to the electricity bill!

Craig

 

[cuslog]

I was reading that home charging stations for Tesla vehicles can use up to 80 amps at 240 volts. What capacity did you rough in for your garage?

Craig

I was wrong -- it's 10 ga. wire they installed for "EV rough in".
Howard

 

[CalgaryPT]

Depending on soil conditions in your area, and length of run, renting a 24" Ditch Witch (Trencher) could save you thousands. Some places offer delivery and pickup as well. They look intimidating, but actually aren't that tough to operate.

 

[Brent H]

10 is good for 30 amps

 

[kevin.decelles]

I rented a trencher from Home Depot last year to do an electrical trench. It was great, 80’ trench, 26” down, 50 minutes (bit I have lots of room to maneuver)

I have a small backhoe, and I’d rent the trencher again vs using the hoe. Right tool for the job


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[kevin.decelles]

If you are in Calgary I have lots of that red warning electrical burial tape. Never going to use it


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[YYCHM]

I rented a trencher from Home Depot last year to do an electrical trench. It was great, 80’ trench, 26” down, 50 minutes (bit I have lots of room to maneuver)

I have a small backhoe, and I’d rent the trencher again vs using the hoe. Right tool for the job

How wide a trench did that thing make?

 

[kevin.decelles]

Between 4” and 6”


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[kevin.decelles]

About 20 years ago you could put electrical and gas on top of each other separated by a 2x4 …. Not sure now


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[CalgaryPT]

I rented a trencher from Home Depot last year to do an electrical trench. It was great, 80’ trench, 26” down, 50 minutes (bit I have lots of room to maneuver)

I have a small backhoe, and I’d rent the trencher again vs using the hoe. Right tool for the job


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[Perry]

Thank you for all the input guys.

Well I'm up late playing with CAD figuring out my plan.

The first estimator called me this evening with a possible issue. The Enmax lines run on the opposite side of the alley from me. With the (max) 900mm mast on the peak of the garage I may not have enough clearance in the alley to meet the 5.5M requirement. The peak of my garage runs 90degress to the alley. Moving the mast to the other end of the garage with a 90mm mast on the peak solves the 5.5M height requirement, but they prefer that you do not run the cable over the roof line and if you do, the cable must be a minimum 1 meter above the roof line. (Well that doesn't work well with a maximum mast height of 900mm. )

I walked down the alley and I'm sure I found at least a couple installs that do not meet this requirement, but I want it done correctly.

Without coming back to take a bunch of measurements the installer said my other option is to go over head to the house and back to the garage in the trench. (Not my first choice, I would like to get rid of overhead lines in the backyard.

So, I'm out in the alley at dark......with my laser point, a protractor and a long tape measure just waiting for the police to show up.

The connection to the secondary feed lines (I'm hoping that is the correct term) is approximately 25 feet above ground on the opposite side of the alley.
There is a 4' space between the alley and garage. (I'm on a corner lot. My driveway runs parallel to the alley). The peak of the garage to the ground is 13'.
Now the alley is approx. 6" lower then the ground beside the garage. I used the height from the ground beside the garage. I used 25' for the connection point to error on the side of safety, it's probably closer to 26'++. As you can see in the CAD it just touches the corner of the 5.5M alley clearance.






So I thought about going to the corner but the line still passes over the roof. I was surprised the clearance was good in the alley.





I'm thinking of contacting a city inspector tomorrow and see what he thinks of these.



@cuslog They quoted me $600 for the trench also. I think I need the exercise. Cheaper then a gym membership.

 

[kevin.decelles]

The 600 is not a bad price..... Renting the trencher (1 day rental) was like $280.... add to that the time to get home, trenching time, washing the machine and returning it......

Of the 3 quotes to do my electrical.... only one included the trenching and they quoted $2000 (the I don't want to do it price). The other two companies said it was a loss leader for them. None of the companies could be bothered to contact Fortis to get a quote on upgrading my service from the pole to the house to upgrade me from 100 to 200 amp. Too much work as the line is ~400 feet.

I hope you're getting better quotes.