LCHCS stuck at 12A

[DeaneG]

Yeah that sounds about right

It'd be cool if Lucid would at least fix the LCHCS home page units typo, and that problem with 192.168.1.x networks. At least show it's still cared about.

 

[MacBain00]

Great question. This same circuit has supported an EVSE on a NEMA 14-50 plug for the past 10+ years. I swapped out the plug and now have the Lucid unit hardwired in the same spot.

50A breaker, 6AWG wiring, dip switches set for 40A. I even tried setting the DIP switches at the 32 A setting, just to see if I had misread up for down. Same result - 12 A.

I think you need to check from the breaker and the unit itself. Make sure you get 50A at the breaker. Then make sure the unit itself is receiving 50A at the lugs. Then keep moving forward until you eliminate it at the unit itself. It's possible you have a bad unit, but I haven't seen posts like that on the forums.

Are you using the proper lugs on the ends of the wires to connect to the charger? If you did a simple replace of the existing wires of the plug to the charger, maybe you need to do a new cut/strip/connector.

 

[geosynch]

I think you need to check from the breaker and the unit itself. Make sure you get 50A at the breaker. Then make sure the unit itself is receiving 50A at the lugs. Then keep moving forward until you eliminate it at the unit itself. It's possible you have a bad unit, but I haven't seen posts like that on the forums.

Are you using the proper lugs on the ends of the wires to connect to the charger? If you did a simple replace of the existing wires of the plug to the charger, maybe you need to do a new cut/strip/connector.

I have a hydraulic crimper from when I did a Miata EV conversion in my garage. I crimped on pure copper lugs (tinned) for 6AWG wire.

But it can only be the unit itself or the installation. As soon as I get the motivation to open the unit back up, I'll verify the open circuit voltage at the lugs and also under a 12A load. If there is any voltage drop at all, then we will have our problem (likely a bad crimp).

 

[Pragmatic]

Unless there is high resistance on the supplyside I would think the problem is the charger.

Make sure the charger is set to 40 amp, connect the car at a low state of charge and wait. After charging for an hour or more use a non-contact thermometer to check temperatures of the breakers, the wiring, the ESVE connections. The one that is hot (or very warm) is what you should check for issues first.

 

[geosynch]

Unless there is high resistance on the supplyside I would think the problem is the charger.

Make sure the charger is set to 40 amp, connect the car at a low state of charge and wait. After charging for an hour or more use a non-contact thermometer to check temperatures of the breakers, the wiring, the ESVE connections. The one that is hot (or very warm) is what you should check for issues first.

I actually don't have a non-contact thermometer, but I could use this to justify getting one.

Here is a photo of the type of lug I'm using. The bolt hole is just the right size for what the contact block uses, and there is no room for a wider lug. In other words, I can't use a bigger lug.

 

[DeaneG]

I swear I searched for similar!

See @nadler1ny 's comment:

N

Post in thread 'Finally got WiFi working ... kind of'

Jun 4, 2025

I just had my lucid charger installed. I can't seem to get past step 3 which says" once your laptop is connected to the wi-fi network of the charging station, open your preferred web browser, enter the station's ip address 192.168.5.1"
I get connection refused each time. I've shut the breaker off numerous times and started the process over but i get the same error.
Since other have had this issue, any fixes other than ethernet which i don't have available?

• nadler1ny

 

[Pragmatic]

Depending on how comfortable you are around live power leads, you could charge for an hour or so and while charging get a voltage reading at the following locations:
Power into breaker panel
Outlet of 50amp breaker
Inlet to EVSE

The one with the largest drop is your likely problem area. I believe the EVSE measures voltage before charging begins and measures the voltage drop as current is increased. Too large a drop and the EVSE cuts the current to limit the heat generated by the high resistance.

 

[geosynch]

I should re-title this thread to "LCHCS stuck at 12A." Maybe someone with more privileges than I have can do that...?

I now understand my 12A limit isn't because I (still) can't get on WiFi. I'll worry about that later (or give up on it entirely).

There is a 1.1 V drop in voltage between open circuit and under a 12A load. That seems way too high to me, but, I'm a lowly retired rocket scientist and can't say for sure. I've reached out to customer service with this information. Nothing in reply yet.

Deets in the linked slide deck.

Lucid Charger INstallation

My (sub) panel that has the 50A breaker

docs.google.com

 

[borski]

I should re-title this thread to "LCHCS stuck at 12A." Maybe someone with more privileges than I have can do that...?

 

[Pragmatic]

If I'm calcualting correctly, always a problem when an ME does electrical things, that 1.1v will be close to 150w of heat if charging was allowed at 40a (13w at 12a), way too much. Even 13w will heat up the offending component after charging a while. Safely find the hot component and you have where you need to improve the circuit.

 

[geosynch]

If I'm calcualting correctly, always a problem when an ME does electrical things, that 1.1v will be close to 150w of heat if charging was allowed at 40a (13w at 12a), way too much. Even 13w will heat up the offending component after charging a while. Safely find the hot component and you have where you need to improve the circuit.

I get 44W at 40 A and 13W at 12 A. But I'm also an ME, hahaha. Even so, 44W is too high.

God as my witness, this same circuit has supported a NEMA 14-50 plug-in EVSE for like 10 years now. THe only difference is the plug is gone, and lugs have been crimped on to the end.

But, I can't argue with data.

I'll be traveling for a week and when I return, I'll have a shiny new contactless thermometer and will test this more under load.

 

[Pragmatic]

For 12a - 1.1v x 12a = 13.2w

For 40a 4v x 40a = 160w (voltage drop will increase with the current)

 

[geosynch]

For 12a - 1.1v x 12a = 13.2w

For 40a 4v x 40a = 160w (voltage drop will increase with the current)

I see what you did there!

Agree that additional V drop is likely, and linear.

 

[DeaneG]

This amount of voltage drop is normal.

 

[johnse]

This amount of voltage drop is normal.

This is my impression as well. In addition to the 50A breaker and the (likely) short length of wiring to the EVSE, there's also the leg from the main panel to this sub panel.

What is the breaker feeding the sub panel?

Dissipating 160W along 100 feet of wiring is not really that much.

But I am not a licensed Electrician...so take my statement with a grain of salt.

 

[johnse]

Adding to my prior note... It would appear from general searching that 2.5-3% is considered acceptable voltage drop, which would be as much as ~7V.

 

[geosynch]

Adding to my prior note... It would appear from general searching that 2.5-3% is considered acceptable voltage drop, which would be as much as ~7V.

Interesting.

To answer other questions:

1. This subpanel is on a 100A breaker
2. The sub is maybe 40 feet from the main panel
3. The EVSE is within 50 feet of the sub-panel 6AWG wire

Thanks everyone for your feedback. I'm still waiting for Lucid Customer Care to respond. I'm outa town for a few days, so, there will be no more sluething until I return.

I did find this voltage drop calculator online. It tells me that for 245V, 12A, 50' of 6AWG copper wire the expected voltage drop should be 0.6V. So, it sounds a bit high, but not crazy high.

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

 

[DeaneG]

...
I did find this voltage drop calculator online. It tells me that for 245V, 12A, 50' of 6AWG copper wire the expected voltage drop should be 0.6V. So, it sounds a bit high, but not crazy high.

With a 50-foot connection, you have 100 feet of wire round trip. Also, there will be some voltage drop in the 50A circuit breaker and its connection to your panel. And the main breaker and its connection to your local utility transformer, etc.