wiring needs for V2H vs level 2 charger?

[stephane47]

Hi all - I'm about to move my level 2 charger outside, and wiring will be underground in conduit. If I want to be ready for V2H, should I put in different wiring than the default for level 2? I won't be able to re-run conduit later, and I assume fishing new wire through would be near impossible.
Thanks for any help/advice/suggestions!

Sponsored

 

[SANZC02]

Hi all - I'm about to move my level 2 charger outside, and wiring will be underground in conduit. If I want to be ready for V2H, should I put in different wiring than the default for level 2? I won't be able to re-run conduit later, and I assume fishing new wire through would be near impossible.
Thanks for any help/advice/suggestions!

I would run oversized conduit now and just use the wire required for your charger. Then if you need larger wire later they can just pull it through the conduit when it is needed.

 

[Nixapatfan]

A lot will depend on what your vehicle and the external inverter will support so highly depends on what you purchase later down the road. Ideally you'd want the highest rating passible to support your whole home. The GM kit is upto 9.6kw.

 

[VSG]

The one thing I would plan for is to use much thicker wire. The R2 supports (I think) 22kW sent back to the house, which is twice what a L2 charger is rated for, so the wiring will have to go up in size to accommodate the higher current. And an L2 charger typically only uses three wires, but I would run 4 in case the V2H charger needs the fourth wire.

It's all a little speculative at this time because the hardware doesn't exist yet.

If you just run a larger conduit like @Nixapatfan suggested, be sure to calculate how much space the above will take and leave yourself plenty of room. But depending on the length of your run, it might be cheaper in total just to run the heavier wire right now so you don't have to pay for pulling the heavier wire in the future, or pay for one cable now and another in the future. Wire is expensive.

 

[justinkitswa]

If it were me, I'd run my existing wire needed for the L2 charger in one conduit and drop another 1-1/2" (inch and a half) PVC conduit in the same trench for the future pull.

By the time you've dug a trench, dropping another conduit in should be pretty cheap.

With the empty 1-1/2" PVC conduit any electrician should be able to pull the correct cable for the future V2H connection alongside any control wiring that would be needed.

I'd not try and guess on adding the additional copper wire as you really don't know the rating of future V2H.

An 1-1/2" conduit would allow you to run up to 2/0 THHN conductors (195 amps at 90 Deg C, or around 45 kW)

 

[Zoidz]

Hi all - I'm about to move my level 2 charger outside, and wiring will be underground in conduit. If I want to be ready for V2H, should I put in different wiring than the default for level 2? I won't be able to re-run conduit later, and I assume fishing new wire through would be near impossible.
Thanks for any help/advice/suggestions!

As long as the conduit fill % is not exceeded, fishing new wire in should be not much more difficult that the original pull. Typically the old wire is used as the pull rope for the new wire, or you pull the old wire out with a pull rope connected to it, and do the new pull with the rope. It all depends on the wire and conduit sizes involved. As someone mentioned above, since you don't have V2H specs I would run two conduits and be done with it. PVC conduit is cheap, and oversizing the PVC makes the pull easier. The possibility exists that you might need line voltage (power) wire and low voltage wire for signal/control. You cannot run both in the same conduit.

If you are running the PVC yourself (or want to make sure the electrician is doing it right), keep in mind that NEC specifies a maximum of 360 degrees of bends/sweeps, such as a maximum of four 90 degree elbows. Also, a pull with 180 degrees of bends is a lot easier than a pull with 360 degrees of bends.

 

[Eric9610]

I ran to all charging locations 100amp capable 4wires. 1 run is far so planned ahead, the other is on the inside of where my panel is.

I agree with everyone on here, run over sized conduit to support the larger 4 wire potential.

 

[Dasoss]

If it were me, I'd run my existing wire needed for the L2 charger in one conduit and drop another 1-1/2" (inch and a half) PVC conduit in the same trench for the future pull.

By the time you've dug a trench, dropping another conduit in should be pretty cheap.

With the empty 1-1/2" PVC conduit any electrician should be able to pull the correct cable for the future V2H connection alongside any control wiring that would be needed.

I'd not try and guess on adding the additional copper wire as you really don't know the rating of future V2H.

An 1-1/2" conduit would allow you to run up to 2/0 THHN conductors (195 amps at 90 Deg C, or around 45 kW)

You can have a limited number of bends or degrees of bends and still pull wire through a conduit. With buried conduit, pulling Ls and junctions are not possible, so pulling cable later is impossible.
Most available Level 2 chargers will not accept heavier wire. There's no room in the terminals. Running heavier wire is a non-starter.
You might be better off installing local storage like a powerwall and eschuing V2H altogether.

 

[justinkitswa]

You can have a limited number of bends or degrees of bends and still pull wire through a conduit. With buried conduit, pulling Ls and junctions are not possible, so pulling cable later is impossible.
Most available Level 2 chargers will not accept heavier wire. There's no room in the terminals. Running heavier wire is a non-starter.
You might be better off installing local storage like a powerwall and eschuing V2H altogether.

Conduit is designed to support cable pulls up to 360 degrees 'worth' of bends without needing an Ell or pull box. So a conduit that drops vertically down the wall of your house, then goes horizontal has 90 degrees of bend. Once that conduit gets to where your point of connection is and goes vertical again (stub up) that's another 90 degrees of bend - so now we're at 180 degrees 'worth' of bend - still OK to pull wire and cable. If you need to add a 30 degree dogleg in the middle of the conduit run, you'd be up to 210 degrees.... Still ok to pull wire.

The installing electrician should know this and plan the conduit run and trench accordingly.

If you oversize the wire to the L2 charger, you'd need to plan on a junction box to make a splice to reduce the wire size before the wire enters the charger - so if you pulled #4 AWG to the L2 charger, and it only accepts #6 AWG - you'd need a splice to drop from #4 to #6 - all perfectly acceptable per NEC code.

Sponsored