Can dig a trench myself - can I get the quote down?

Nom

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#1
Hi - I have a detached garage and will need to run a new higher Amp line run out to it for a charger. Far bit of distance. Got a quote from Tesla and the majority of the quote is the trenching cost ($35/ft !!!!). I let them know in the original ask that I can dig the trench myself ... heck I did it 5 years ago when I ran the current line out to the garage (didn't think to have a high amp line run out!). Seems like they ignored that part of my message.

Anyone able to convince the Tesla energy folks to let the buyer dig their own trench? I've reach out again ... likely won't hear until Monday. If you all think this is doable I'll probably start digging tomorrow (Sunday)!
 

GDN

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#3
Yes - as long as it's deep enough you should be able to dig the trench and I would think anyone should adjust their quote if you do that part. If not dig the trench and then call for a new quote, perhaps even from a different electrician.
 

TrevP

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#4
Check your local electrical codes to make sure the depth is correct for the frost line
 

ADK46

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#5
Though I had a Model 3 reservation, I very nearly wired up my new detached garage with just 50A service. This was a garage for my vintage cars, but no one should build a garage today without at least 100A. I might electrify one of these old cars someday.

I believe code requires a 24" depth - my solar installers just dug a trench. Don't forget to run an ethernet line! Not in the same conduit, though - can't mingle high and low voltage wires in the same conduit. Run a spare ethernet cable - lightning is hell on thin wires connecting devices in different buildings.
 

Dan D

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#6
I would definitely dig the trench. It doesn't need to be below frost line as it's electrical, not a water service. While you're at it, lay in the 1" PVC conduit with a pull string (and maybe a separate 1/2" for a data cable as suggested) from end to end of your trench and bury it. Google or Home Depot will tell you which conduit to buy for underground electrical installations (and the right fittings). You can DIY a lot of this - just stay away from all of the electrical wire terminations and penetrations into your panel, etc. #6 4-wire for 50-am, #10 4-wire for 30-amp. Give them way more than plenty of wound up wire at each end of your underground piece.
 

justflie

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#7
I did the trench digging for my detached garage. Electrician and I worked out the desired path. He told me how deep and wide to make it. In my case, it needed to be at least 6” wide and 20” deep. It ended up being A LOT more work than anticipated. New England ground is unforgiving, lots of rocks and roots.
 
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Karl Sun

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#9
Don't forget to run an ethernet line! Not in the same conduit, though - can't mingle high and low voltage wires in the same conduit. Run a spare ethernet cable - lightning is hell on thin wires connecting devices in different buildings.
If you're going between bulding with different ground points, run ethernet (single mode) fiber instead. Can go in same conduit as power lines.

All modern switches have the capability to accept GBIC fiber connections.
 

Frank99

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#10
Running fiber to the garage will be difficult. Without fiber termination tools, you'd have to run pre-built/terminated cables, in which case you'd probably have to use 2" conduit for the low-voltage run. As ADK46 mentioned, lightning is a problem with data cables between buildings, so running an Ethernet cable is possible, but depending on the amount of lightning you get in your area may not be advisable.

My recommendation for data out in the Garage is to just use a WiFi link. I've used Ubiquiti products in the past with great success. Something like this.
 

Karl Sun

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#11
Running fiber to the garage will be difficult. Without fiber termination tools, you'd have to run pre-built/terminated cables, in which case you'd probably have to use 2" conduit for the low-voltage run. As ADK46 mentioned, lightning is a problem with data cables between buildings, so running an Ethernet cable is possible, but depending on the amount of lightning you get in your area may not be advisable.

My recommendation for data out in the Garage is to just use a WiFi link. I've used Ubiquiti products in the past with great success. Something like this.
Pulling LC-terminated SM fiber is EASY. If the tubing distance is >75 feet, I would use at east 2-3" tubing. Same size trench. I can travel to PHX to term fiber but MASS is a bit far for me. <g>

Other than mechanical wear during the install, there's no reason you can't put the finer in the same hole/tube as the power cables. Just don't use armored fiber cable and pull the electical power and fiber cables at the same time, all wrapped together.

We don't care how long the fiber is. SM finer is good to at least 20Km without an amplifier (using SR GBICS) at 100Tb speeds.

Note you will need at least 6 feet clearance on the other panel end from any [natural] gas equipment to the power cables.
 
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twww

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#12
We dug our own 12 ft trench @20" depth to reduce the cost. Minimum depth for electrical in CT is 18". Almost wished we hadn't. Brutal New England ground for digging by hand. If you are planning to do it with a machine make damn sure you dial 811 (it's the law in CT, and probably in MA too) and also get your permits in order. Had a local electrician do the conduit and all electrical work. Less than $500
 

Bokonon

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#13

Nom

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#14
Hi all, sorry for delayed reply. Tesla said that that their quote services require the contractor to dig the ditch. Would not reduce the quote if I said I'd do it.

Thanks for all the advice above. I'm thinking of options B, C, and D now!!