[p7wang]

Saw this on the Tesla site talking about someone's panel smoking possibly due to poor contact of the new breaker and possibly bad electrical panel. Anyone have similar experience after adding a 240?

A cautionary tale of a NEMA 14-50 installation

I picked up my car at the factory on Saturday and had the electrician come over to install my NEMA 14-50 outlet bright and early this morning. After about an hour, he was finished and the install looked nice an clean. I wrote him a check, he went on his way, and I quickly plugged the...

teslamotorsclub.com

 

[Like2bike]

The bottom line is whenever setting up a new charge connection you should always stay around a make sure nothing is overheating. My L2 installed without a hitch. Once at vacation rental house I had a scary problem with L1. Even though I was careful to check nothing was overheating, there was an fault in the service feed to the house that almost started a fire. Apparently the neutral line back to the pole can be faulty without it causing a problem for most uses. When running L1 overnight in the morning the internet service suddenly went out. The cable connection to the house was fried because the cable had been carrying the neutral current back to the pole.

 

[srnewby54]

I had an L2 installed at my house a few weeks ago. No problems with the installation and no problems with charging so far. I did check the first few times to see how hot my portable charging unit got, but it was just warm so that alleviated any anxieties I had.

 

[XJ12]

I've used a very cheap IR temperature gun to scan my box for any out of family temps. These things used to be expen$ive but now they practically give them away.

Amazon.com: Glanzix Temperature Gun Infrared Thermometer w/ Laser Sight: Industrial & Scientific

Amazon.com: Glanzix Temperature Gun Infrared Thermometer w/ Laser Sight: Industrial & Scientific

www.amazon.com

 

[California]

I've used a very cheap IR temperature gun to scan my box for any out of family temps. These things used to be expen$ive but now they practically give them away. HDE-Non-Contact-Infrared-mometer

That's a great price ($15) for what it is. Much better in features, than the little Harbor Freight Non-Contact Pocket Thermometer ($12) that I have, which is smaller and lacks an aiming laser.

Quote from that 2013 Tesla group post:

Research Federal Pacific boxes. You should definitely be concerned and replace it. They do not meet UL specifications and have an extremely high failure rate. The same goes for Zinsco boxes.

Yeah. As I've posted here before I put two 1500 watt space heaters on in the guest cabin, on different 20 amp circuits, and that little load burned up the 100 amp main breaker in the barn sub-panel, that fed the cabin's own more modern panel. At least the breaker failed by tripping irretrievably. Federal Pacific, installed 1967, possibly a used panel from a garage sale at that time. I found a new-old-stock replacement for the failed main breaker but I don't have much faith in it. I'm careful to never overload any circuit that runs from the barn panel after reading many warnings about FP breakers.

Anybody - if your old house has a Federal Pacific panel - replace it!

 

[p7wang]

I had an L2 installed at my house a few weeks ago. No problems with the installation and no problems with charging so far. I did check the first few times to see how hot my portable charging unit got, but it was just warm so that alleviated any anxieties I had.

I was reading on another thread that the OEM EVSE (with its original 5-15P) has built-in heat sensor, so the worse case should be that the charging stops on its own vs the alternative of EVSE burning up or electrical wiring burning up.

 

[Vertiformed]

I was reading on another thread that the OEM EVSE (with its original 5-15P) has built-in heat sensor, so the worse case should be that the charging stops on its own vs the alternative of EVSE burning up or electrical wiring burning up.

The heat sensor in the plug will handle the common issue of a badly connected outlet that overheats. It won't catch other issues with the wiring, such as a problem back at the breaker panel.

 

[JaxEVLyftUber]

Anywhere a connection is not properly tight is a candidate for arcing and overheating. That includes where the circuit breaker mates with the panel busbar.

I also agree that an IR scan can be useful, but should be done only after circuit(s) of interest are and have been under load for awhile. Heat will not be generated when the circuit is not in use.

 

[ZoomZoom]

I'm thinking this is going to be as rare as a car fire. It can happen, anything can happen, but it takes a couple seconds to check the tightness of the connections. The JuiceNet knows the temperature, but I seriously doubt that it has any logic to shutdown based on a temp.

 

[p7wang]

At what temp reading on the circuit breaker body should one start worrying?

 

[XJ12]

At what temp reading on the circuit breaker body should one start worrying?

Not an expert on this, but from what I can google, above 60C (running at 80% load) seems to be where one might be concerned. For me, I'm running only 12 amps through my 40 amp breaker so didn't see much of anything when I checked.
edit: check out this thread

 

[Gireya]

Saw this on the Tesla site talking about someone's panel smoking possibly due to poor contact of the new breaker and possibly bad electrical panel. Anyone have similar experience after adding a 240?

A cautionary tale of a NEMA 14-50 installation

I picked up my car at the factory on Saturday and had the electrician come over to install my NEMA 14-50 outlet bright and early this morning. After about an hour, he was finished and the install looked nice an clean. I wrote him a check, he went on his way, and I quickly plugged the...

teslamotorsclub.com

Yes, I did. I installed a 10kw solar system with a 7.6 kw SolarEdge Inverter with an intergrated L2 charger a year ago. Everything was installed per the engineering that was supplied by the vendor. The electrical inspector commented that it was the cleanest install he had seen. The electric coop and building department also inspected the system and signed off on it.

Everything was working great, the system was supplying enough electricity for our home, Bolt and creating enough extra for a small check at the end of the year. One day about six months after the system was commissioned I checked the app and noticed it and was offline. After a quick inspection I found that the fuses were burned up and the insulation was melted off the conductors in the AC disconnect on the outside of my garage.

I called the vendor and their engineer concluded that the circuit was too small and that I need to replace it with a 80 amp circuit and appropriate conductors, #6awg!! The materials alone would cost $1500.00.The labor to would be probably triple that. Fortunately their engineer was full of ****. I called SolarEdge and talked to one of their techs and he confirmed that the circuit was sized properly.

After a ton of googling I concluded that the AC disconnect was either faulty and or the conductor was not properly tightened in the lug. The vendor sent me a new disconnect and I ordered a torque screwdriver. I reinstalled everything and it's been working flawlessly ever since. I was a carpenter for over twenty years and spent a lot of time with electricians on job sites and never once saw one use a torque screwdriver.

 

[XJ12]

I was a carpenter for over twenty years and spent a lot of time with electricians on job sites and never once saw one use a torque screwdriver.

this is a very common issue in all industries. as an engineer, torque specs are a must that must be enforced ( I've got horror stories). I did my own wiring and used a torque wrench to tighten my electrical connections. It was surprising how much force is actually required for just the breakers. Scary to think that it's "not cool" to check ones work.

 

[Gireya]

this is a very common issue in all industries. as an engineer, torque specs are a must that must be enforced ( I've got horror stories). I did my own wiring and used a torque wrench to tighten my electrical connections. It was surprising how much force is actually required for just the breakers. Scary to think that it's "not cool" to check ones work.

Agreed, I installed my own system and bought a calibrated torque wrench for all the fasteners on the solar panels. We have high wind loads in our area and one of my worst fears it to have the entire array torn off my roof because of a few over/under tightened fasteners fail. I just didn't think about the electrical connections. Also you have to really hunt to find the torque specs for electrical. As a rule tradesmen aren't the most patient, me included.

Not cool was never the motivation when I was on a job site. It always came down to money.

 

[JaxEVLyftUber]

The screw holding the red conductor was probably only finger tight...or less...or some insulation was under the fastener rather than bare copper.

P7Wang asked "how hot is too hot"... XJ12 mentioned 60*C (140*F). That sounds too hot; perhaps some confusion arises over various conductor temperature ratings - 60,75,90, 105*C all being somewhat common. Those temp limits actually apply to the insulation...they are not design operating temperatures for the circuit.

My imprecise but experienced sense is that "a bit warm to the touch" is OK, but uncomfortably hot is not.

I'm not sure I've come across use of torque tools for electrical connections at the residential / light commercial level, but they do need to be pretty darned tight, and an occasional re tightening of everything in a panel is excellent...and will often reveal some fasteners worryingly loose. My own rule of thumb is that a properly tightened fastener clamping a conductor should cause slight to moderate deformation of the conductor...it "leaves a mark" if you will.

Car charging circuits may be among the higher actual power and longest duration loads in a typical home...30+ amps for hours at a time is not duplicated by many other residential loads, so these need to be treated with respect - installed properly and occasionally inspected.

My monthly driving / charging activity exceeds 1 MWh (a megaWatthour, or 1000 kWh) passing through that one circuit every month...more than the combined total of every other circuit in our all-electric centrally air-conditioned home...that circuit works hard!

 

[MikeyBolt]

I don't know what the temperatures should be but as a point of reference, when mine is charging at a full 32A, the part of the breaker you can touch (I'd call it the "top": the part with the lever on it) doesn't even get warm to the touch. It's a 50A breaker with #8 wire going to the L2 charger.

Mike

 

[ZoomZoom]

I don't know what the temperatures should be but as a point of reference, when mine is charging at a full 32A, the part of the breaker you can touch (I'd call it the "top": the part with the lever on it) doesn't even get warm to the touch. It's a 50A breaker with #8 wire going to the L2 charger.

Mike

I'm running #6 wire and I'm feeling and seeing a temp rise over 10 degree's. All connections are very tight. I ran #6, the Juice Box pigtail is #8, I don't have readings on that wire. I will recheck the breaker, but I don't recall a temp increase at the breaker ...... my test was performed after the car was taking 32amps for over 1 hour.

 

[p7wang]

I don't know what the temperatures should be but as a point of reference, when mine is charging at a full 32A, the part of the breaker you can touch (I'd call it the "top": the part with the lever on it) doesn't even get warm to the touch. It's a 50A breaker with #8 wire going to the L2 charger.

Mike

Might be a problem in the future if someone plug in a 40A EVSE.

How to Choose the Right-Sized Electrical Wire

Learn how circuit wires must be sized in a manner that matches the ampacity of the load placed on them. This is a critical safety concern.

www.thespruce.com