HPWC top entry: Reduce 1 inch EMT to 3/4 inch EMT?

[FloridaJohn]

I am trying to install the HPWC, and the wall mount bracket only has a top entry of 1" EMT conduit. I want to run 3/4" EMT conduit back to the breaker box. I can't seem to find any way to reduce the entry into the wall bracket adapter down to 3/4" inch. A reducing washer doesn't work because of the internal obstructions around the inside of the entry into the HPWC wall mount bracket.

Anyone else come up with a solution to this?

 

[365gtb4]

It's called a reducing bushing, pretty common. I'd be careful in sizing the conduit and wire. 3/4 inch won't handle much power, where 1 inch will handle 3 gauge wire and 80 amps as I recall.

 

[Glamisduner]

Can you just drill a 3/4" hole into it? Also you could go from 3/4" conduit to 1" then go into the HPWC?

 

[FloridaJohn]

It's called a reducing bushing, pretty common. I'd be careful in sizing the conduit and wire. 3/4 inch won't handle much power, where 1 inch will handle 3 gauge wire and 80 amps as I recall.

Well, since I have a Model 3, there is no way I can possibly pump 80 amps into it anyway!

 

[FloridaJohn]

Can you just drill a 3/4" hole into it? Also you could go from 3/4" conduit to 1" then go into the HPWC?

Unfortunately not. The plug that is in this particular hole is plastic with a rubber "stopper" to hold it in the hole. If I drill out the rubber stopper then there is nothing to hold the remaining plastic in the case.

My original plan was to go from 3/4 conduit to 1 inch conduit, but that ended up being even more of a hassle because a lot of residential boxes have 3/4 holes as the largest holes in them.

The problem is really just that last connection into the HPWC. IT was obviously originally designed for 80 amps service, but now that Model 3s can only charge at a max of 48 amps, there are a lot of design decisions that don't make sense anymore.

 

[Glamisduner]

Unfortunately not. The plug that is in this particular hole is plastic with a rubber "stopper" to hold it in the hole. If I drill out the rubber stopper then there is nothing to hold the remaining plastic in the case.

My original plan was to go from 3/4 conduit to 1 inch conduit, but that ended up being even more of a hassle because a lot of residential boxes have 3/4 holes as the largest holes in them.

The problem is really just that last connection into the HPWC. IT was obviously originally designed for 80 amps service, but now that Model 3s can only charge at a max of 48 amps, there are a lot of design decisions that don't make sense anymore.

What I'm saying is maybe go to 3/4" conduit to 1" conduit just before entering the box.
I'm above to venture into using 1" conduit into the top of mine. I saw the rubber shenanigans and do not understand what it is for. I'll have to take another look at it when I get home. These things are a real pain to mount

 

[GWord]

A reducing bushing is what you want, probably in conjunction with an inlet offset if you want it to look pretty. It would be nice if you could get a reducing offset inlet but I've never come across that.

 

[Glamisduner]

I found this video showing the 1" conduit screw down adapter.

If you check my thread on my install someone posted a picture of 3/4" conduit running into the top of their HPWC. I would think you could just drill a smaller hole than the 1" hole provided, but I don't understand what you mean by drilling into the rubber thing. Or at least why that would matter?

A reducing bushing is what you want, probably in conjunction with an inlet offset if you want it to look pretty. It would be nice if you could get a reducing offset inlet but I've never come across that.

Have a picture or link?

 

[GWord]

Have a picture or link?

An offset inlet just has a little jog that allows you to get closer to the wall. Its primary usage is connecting multiple boxes together where you need an elevation change but it also works well on the HPWC to get close to the wall without noodling the PVC or doing a tight offset bend (although a true professional electrician would probably do an offset bend just to show off).




You can find offset inlets in PVC as well. For a reducer, you would need the appropriate bushing and maybe something to convert thread gender, depending on the type of offset you use.

 

[Glamisduner]

A reducing bushing is what you want, probably in conjunction with an inlet offset if you want it to look pretty. It would be nice if you could get a reducing offset inlet but I've never come across that.

An offset inlet just has a little jog that allows you to get closer to the wall. Its primary usage is connecting multiple boxes together where you need an elevation change but it also works well on the HPWC to get close to the wall without noodling the PVC or doing a tight offset bend (although a true professional electrician would probably do an offset bend just to show off).




You can find offset inlets in PVC as well. For a reducer, you would need the appropriate bushing and maybe something to convert thread gender, depending on the type of offset you use.

Ahh Just to help line stuff up, gotcha.

I went and bought a ton of 1" stuff because I don't know what I'm doing hah.

 

[brkaus]

As mentioned “photo in other thread” - Here is how the installer did mine. I do not know what the insides look like.

 

[Glamisduner]

As mentioned “photo in other thread” - Here is how the installer did mine. I do not know what the insides look like.

View attachment 368929

To me it looks like they just drilled a smaller hole. But it would be interesting if there was a locking ring inside. Probably doesn't matter though as they likely just threaded into plastic or are using the mount itself to keep everything in place?

 

[brkaus]

Here is the rest of the picture. Could probably get away with anything. Wouldn’t require much support.

 

[GWord]

Ahh Just to help line stuff up, gotcha.

I went and bought a ton of 1" stuff because I don't know what I'm doing hah.
View attachment 368930

That's quite the haul! At least you can take back what you don't need. Do you plan on using PVC or metal conduit?

 

[Glamisduner]

I am trying to install the HPWC, and the wall mount bracket only has a top entry of 1" EMT conduit. I want to run 3/4" EMT conduit back to the breaker box. I can't seem to find any way to reduce the entry into the wall bracket adapter down to 3/4" inch. A reducing washer doesn't work because of the internal obstructions around the inside of the entry into the HPWC wall mount bracket.

Anyone else come up with a solution to this?

I'm trying to figure how to cut the hole in the top of the HPCW mounting bracket, from the videos I see it sounds like it pops out? But mine looks like it a solid piece of plastic. Do I just drill a hole into it from the top with a hole saw? Maybe I have an old generation HPWC or something?

 

[GWord]

I'm trying to figure how to cut the hole in the top of the HPCW mounting bracket, from the videos I see it sounds like it pops out? But mine looks like it a solid piece of plastic. Do I just drill a hole into it from the top with a hole saw? Maybe I have an old generation HPWC or something?

Silly question but, are you using the extra junction box that enables top entrance? It comes wrapped in bubble wrap under some cardboard in the box.

This thing: Tesla Wall Connector Top Entry Bracket TESLA | eBay

You can see the two screw in plugs at the top; one for a 1" HV inlet and one for a smaller inlet for data. You terminate your power feed to the junction block there and then you use the included leads to continue the branch to the terminals in the HPWC.

 

[Glamisduner]

Silly question but, are you using the extra junction box that enables top entrance? It comes wrapped in bubble wrap under some cardboard in the box.

yes

 

[GWord]

yes

Doesn't it have two screw in plugs? I see them in that Ebay picture.

 

[Glamisduner]

Doesn't it have two screw in plugs? I see them in that Ebay picture.

This is the only picture I have on me, but I can take another picture when I get home tonight. The other side has some kind rubber thing attached to the plastic. This was my original plan to install the thing before I learned you can't have the box or 90's behind the wall.

I don't think there are any screw plugs as the top entry is not threaded in all the videos I have watched (none of the videos show how they knock out or drill into the top). I didn't see anything in the manual either.

 

[GWord]

This is the only picture I have on me, but I can take another picture when I get home tonight. The other side has some kind rubber thing attached to the plastic. This was my original plan to install the thing before I learned you can't have the box or 90's behind the wall.View attachment 369387

I don't think there are any screw plugs as the top entry is not threaded in all the videos I have watched (none of the videos show how they knock out or drill into the top). I didn't see anything in the manual either.

Huh, interesting. I’m on the road or else I would look at the two I have stuffed away in my shop. I have two HPWCs at home but I used bottom entry so I didn’t need to use the extra bracket.