Installing Wall Connector on electrical box

[RB88]

Hi all,

Looking to purchase a new townhome. The parking lot comes with an electrical box with a 50A hookup. Right now the box just has a face plate covering it up, but I presume the intention is for owners to install a NEMA 14-50 outlet on it. See attached picture for the box.

My question is - does this look suitable to mount a Gen 2/3 Wall Connector on the front of? Wasn't totally clear from the install manual if that's possible. Or would I be better off hiring an electrician and getting them to modify the cable run and remove the box completely to replace with the wall connector? (trying to avoid if possible because electricians charge an arm and a leg in Seattle for EV-type work!).

Obviously option 3 is installing an outlet there instead and using the plug-in wall connector or mobile connector, but would like as clean a job as possible.

Thanks!
Rik

p.s. I know the photos show two different boxes. The one marked "E" is the one in my assigned space - we just opened up another one before by accident.

 

[RB88]

Actually occurs to me looking at it it might not be all that hard for me to remove the box and mount the wall connector on the wood myself, keeping the existing tubing for the cable run for bottom entry. Rather than hire someone.

 

[Aikidoka]

Looks like it would be easier to remove the box and mount the wall connector to the wood. Just make sure the wires are long enough to enter through the bottom of the wall connector and wrap around to the connectors. I have a similar situation where I want the wall connector about a foot higher so have to pull new wires. Fortunately, the entire run will only be 6'.

 

[swaltner]

Good to see the builder put that in on the new construction. It costs them "nothing" to add it when the house is being built and costs a "fortune" to retrofit it. I know some places have it in code that new construction needs to at least be roughed in (run a conduit with no wire is acceptable) for EV charging. Really good to see builders planning ahead!

Of course, this could have been done by your request and cost, depending upon how early in the build process you signed the purchase agreement.

 

[Watts_Up]

Hi all,

Looking to purchase a new townhome. The parking lot comes with an electrical box with a 50A hookup. Right now the box just has a face plate covering it up, but I presume the intention is for owners to install a NEMA 14-50 outlet on it. See attached picture for the box.

My question is - does this look suitable to mount a Gen 2/3 Wall Connector on the front of? Wasn't totally clear from the install manual if that's possible. Or would I be better off hiring an electrician and getting them to modify the cable run and remove the box completely to replace with the wall connector? (trying to avoid if possible because electricians charge an arm and a leg in Seattle for EV-type work!).

Obviously option 3 is installing an outlet there instead and using the plug-in wall connector or mobile connector, but would like as clean a job as possible.

I would recommend to keep the box as it is and use it as a connection box.

Find the optimum location for your Wall mount charger, depending of how you plan to park your car.
Best location would be to have the plug going above your car instead to have it on the floor.

Then connect the Wall mount charger to your connection box using a flexible wire or a 3/4" or 1" conduit, you don't need the neutral.

To connect the wires inside the connection box, use those waterproof Polaris connectors:
(You need one for each wire, the top holes are used for the screws)

 

[iluvmacs]

Agreed, I would just mount the HPWC above this box somewhere and run some conduit (rigid or flexible) from the top of the box to the HPWC, bottom-entry.

 

[RB88]

Good to see the builder put that in on the new construction. It costs them "nothing" to add it when the house is being built and costs a "fortune" to retrofit it. I know some places have it in code that new construction needs to at least be roughed in (run a conduit with no wire is acceptable) for EV charging. Really good to see builders planning ahead!

Of course, this could have been done by your request and cost, depending upon how early in the build process you signed the purchase agreement.

Yep the builder put them in for all of the assigned parking from the start. I have seen this for most of the new constructions with garages in Seattle (usually including a 14-50) but only for some with off street parking. I think it’s a big plus for townhouses without garages because it can be difficult to run the wiring to the off street parking if you’re not the back unit...

I would recommend to keep the box as it is and use it as a connection box.

Find the optimum location for your Wall mount charger, depending of how you plan to park your car.
Best location would be to have the plug going above your car instead to have it on the floor.

Then connect the Wall mount charger to your connection box using a flexible wire or a 3/4" or 1" conduit, you don't need the neutral.

To connect the wires inside the connection box, use those waterproof Polaris connectors:
(You need one for each wire, the top holes are used for the screws)

Just curious why I would want to use it as an intermediate connection box vs just replacing it with the wall connector itself?

What do you mean exactly by “the plug going above the car”?

 

[mociaf9]

Just curious why I would want to use it as an intermediate connection box vs just replacing it with the wall connector itself?

Much easier to remove and return to original condition or to do anything else with. This would be a bigger consideration if you were renting instead of buying, but may still be something to think about. If you consider moving/selling at some point in the future, you'll likely take your HPWC with you which means you'd have to replace the box. Or you may decide that you want a 14-50 installed there instead of the HPWC at some point. Basically, leaving the box and mounting the HPWC above it is a way to leave future options more open and it shouldn't cost you anything appreciably extra to do it that way. But neither is it necessary.

 

[MikeHolliday]

Hi all,

Looking to purchase a new townhome. The parking lot comes with an electrical box with a 50A hookup. Right now the box just has a face plate covering it up, but I presume the intention is for owners to install a NEMA 14-50 outlet on it. See attached picture for the box.

My question is - does this look suitable to mount a Gen 2/3 Wall Connector on the front of? Wasn't totally clear from the install manual if that's possible. Or would I be better off hiring an electrician and getting them to modify the cable run and remove the box completely to replace with the wall connector? (trying to avoid if possible because electricians charge an arm and a leg in Seattle for EV-type work!).

Obviously option 3 is installing an outlet there instead and using the plug-in wall connector or mobile connector, but would like as clean a job as possible.

Thanks!
Rik

p.s. I know the photos show two different boxes. The one marked "E" is the one in my assigned space - we just opened up another one before by accident.

You do not mount the Gen 3 Wall Charger on top of a J Box. The Gen 3 Wall Charger is designed to be mounted drectly to a wall with a conduct bringing the the power into the Wall Connector. (See the attached pictures.)

For those contemplating installing a Gen 3 or other Wall Connector, can I please give some advice before you cause future issues.

Before starting the project you must measure the current maximum Load that your house, condominium office or other location is pulling through the Load Center (Breaker Box). Without doing so you can damage your charger or perhaps more serious issues. I will explain more of this as I go. To measure your total Current Load here is what you need to do using a Clamp Meter, (If in doubt have the done by a qualified electrician)

1.) Remove the front panel from your Load Center
2.) You then must turn on every Light in in the Home, Microwave, 1 Vaccum Cleaner, Dishwasher, 1 Hair Dryer, Air Conditioner and all Stove Tops and Ovens, etc.
3.) Then with everything on, using a Clamp Meter, you are to measure the total amperage on Leg 1, Leg 2 & Neutral.
4.) Now shut everything off.
5.) The Gen 3 Connector needs a 60 Amp Breaker, not 50 Amp. The NEMA14-50 (a 50 Amp Circuit) is used with the Tesla Corded Mobile Connector.
6.) Let's say that you have a 125 Amp service on this Load Center and you measured as an example 85 Amps on Leg 1 & 90 Amps on Leg 2, then you cannot install a 60 Amp breaker. 125 Amps minus 90 Amps on gives you 35 Amps, so that would be the largest Breaker that you cound install.
7.) If you do not have the power, then you need to upgrade your Load Center and in this example it would increase your service from 125 Amps to 200 Amps.

And never ever use any wire smaller than AWG6. Tesla specifies AWG 6 on Page 6 of the Installion Guide for a reason. The Gen 3 draws 48 Amps at maximum output, but you must add 20% to that figure for the necessary Breaker size. 48 Amps times 1.2 puts you at 57.6 Amps (60 Amp Breaker)

Here is the what happens if you do not do so, you end up in a current starvation issue. If you have your Car charging, and a number of appliance are turn on, then you can overheat and damage many items, including your Tesla Wall Connector,Refrigerators, Air Conditioners, etc. I am convenced that this is why a number of individual have had their Wall Connectors die after a year or so. It is not just wires that get hot when there is current starvation situation, that heat carries over to the Electronics!

 

[RB88]

5.) The Gen 3 Connector needs a 60 Amp Breaker, not 50 Amp. The NEMA14-50 (a 50 Amp Circuit) is used with the Tesla Corded Mobile Connector.

This isn’t true, no? The manual explicitly states (on page 5) the max amperage of the circuit can be selected and it will work appropriately, just charging slower. I’ve read plenty of posts of people using it on 30A/50A etc.

 

[mongo]

2.) You then must turn on every Light in in the Home, Microwave, 1 Vaccum Cleaner, Dishwasher, 1 Hair Dryer, Air Conditioner and all Stove Tops and Ovens, etc.

That is in no way the correct method of performing an NEC load calculation.
Residential Calculations: Estimating Elements of the Electrical System

3.) Then with everything on, using a Clamp Meter, you are to measure the total amperage on Leg 1, Leg 2 & Neutral.

Even if you were doing it this way, there is no reason to measure neutral.

5.) The Gen 3 Connector needs a 60 Amp Breaker, not 50 Amp. The NEMA14-50 (a 50 Amp Circuit) is used with the Tesla Corded Mobile Connector.

Incorrect, Gen3 can be to connected to a 15Amp breaker (12 Amp charge rate), among others.

6.) Let's say that you have a 125 Amp service on this Load Center and you measured as an example 85 Amps on Leg 1 & 90 Amps on Leg 2, then you cannot install a 60 Amp breaker. 125 Amps minus 90 Amps on gives you 35 Amps, so that would be the largest Breaker that you cound install.

Incorrect, use the NEC duty adjusted calculation.

And never ever use any wire smaller than AWG6. Tesla specifies AWG 6 on Page 6 of the Installion Guide for a reason.

Incorrect, the unit can be connected to 12AWG.

Caveat: 6AWG NM-B (Romex) is only rated to 55 Amps (60C column).

The Gen 3 draws 48 Amps at maximum output, but you must add 20% to that figure for the necessary Breaker size. 48 Amps times 1.2 puts you at 57.6 Amps (60 Amp Breaker)

Continuous loads get a 125% multiplier. 48 Amp charge requires 60 Amp circuit (80% derating).

Here is the what happens if you do not do so, you end up in a current starvation issue. If you have your Car charging, and a number of appliance are turn on, then you can overheat and damage many items, including your Tesla Wall Connector,Refrigerators, Air Conditioners, etc.

You would either get voltage droop or a tripped breaker, current starvation is not a thing.
Low line voltage can damage motors which act differently than the vehicle's charger.

I am convenced that this is why a number of individual have had their Wall Connectors die after a year or so. It is not just wires that get hot when there is current starvation situation, that heat carries over to the Electronics!

The wall connector is some brains and a contactor. The unit is rated down to 200V. Low voltage will not damage it. Further, the car will reduce charge current if there is excessive voltage drop.