Mobile Charger Issue with 14-50. Works fine with 14-30.

[AlexanderWD]

I recently had a 14-50 outlet installed, but as soon as I went to use the mobile charger I got nothing. The charger does not light up when plugged in. The charger works fine with a 14-30 or 120v adapter and outlet.

I have tested two different 14-50 adapters and checked the outlet carefully to make sure it was properly installed. It was. Yet, no matter what the mobile charger is dead when I try to plug it into the 14-50. There are no lights. Nothing. Can anyone point me in the right direction for possible solutions?

 

[flixden]

If the 40A is working right and measures 240V and the 50A does not, @Sophias_dad is probably right.

From the picture, you are using a THQP250, which is a compact half sized breaker:
GE Q-Line 50-Space Amp 1 in. Double-Pole Circuit Breaker THQP250 - The Home Depot

You can see how they clamp on the panel using the two clamps that are perpendicular to the breaker:
View attachment 987200

Conventional full size THQL breakers instead use parallel clamps that clamp onto the slots.
View attachment 987201

It's possible to install such half size breakers such that both sides are on the same phase when you install a double pole. That is one of the downsides to using such space saver breakers. The full size breakers won't have this problem because they would always be on an alternating side.

Here's a diagram of how the various breakers clamp onto the panel:
View attachment 987202

Here's a labeled picture assuming the 40A is connected correctly. The red bars simulate how the slots are. The numbers correspond to which side slot each breaker is connected to. You can see the 50A breaker would end up having both sides connecting to the same slot, so they would be on the same phase.

View attachment 987203

I think you nailed it. Moving the 50A double one position up or down will most likely solve the issue.

 

[mongo]

Not related, but most breakers don’t allow a double tap either. 4th and 5th down.

Especially with different gauges!

 

[mongo]

I think I see the problem.

You have an open somewhere on one of the hots.

From the top: Your house has two phases of hot; 120VAC/_0 degrees, and 120VAC/_180 degrees.

Second: If you take a multimeter and stick one probe on the ground frame and put the other probe on either the Big Red Wire or the Big Black Wire, you'd expect to get 120 VAC to either of those wires.

But you said that you put the probes of the multimeter across the Big Red Wire and the Big Black Wire and got Zero volts. Whoops!

Now, as a thought experiment, suppose that the breaker connected to the Big Black Wire happens to be busted and is open. And you've got the Mobile Connector plugged into the socket.

Under this scenario, there's 120/_0 degrees on the Big Red Wire since its breaker is in good working order. That voltage goes all the way down to the socket, into the wire in the mobile connector, through A Lot Of Resistance (but not infinity resistance) in the Mobile Connector, back into the other hot wire in the Mobile Connector, back to the wall socket, onto the Big Black Wire, and There It Stops. 120VAC/_0 degrees on both the Big Red Wire and the Big Black Wire.

Remember that there's not a lot of current flowing around in here; the multimeter has an internal resistance of MegaOhms and the internal resistance of the Mobile Connector is probably a couple of hundred kOhms.

Result: 120 VAC/_0 degrees on both Big Wires, so the voltage difference between them is Zero. Check. The voltage difference between the Big Red or the Big Black and Ground/Neutral is 120 VAC, check.

Like I said, you got an open somewhere. Could be:

1. The duplex breakers clip onto the two hot bus bars. One or the other of the clips might not be working right.
2. Breakers are mechanical devices. The get broken. If you're confident in your abilities (and, seriously, don't do this if you're not), turn off the power to the breaker panel, pop the breaker out of the panel (it clips, like I said), and check for continuity from a clip to the red wire and the other clip to the black wire. Then turn off the breaker and verify that both sides go to open. Use the Ohms function on your multimeter.
3. Check continuity of the red wire to one of the hots on that NEMA14-50 socket contacts and verify that there's no continuity from that red wire to any of the other blade connections.
4. Check continuity of the black wire to the other hot on that NEMA14-50 socket and verify that there's no continuity from that black wire to any of the other blade connections.

You're likely going to find something busted in steps 1-4 above. Fix whatever it is, put the breaker back where it came from, turn on the power, and check things.

By the by: If you're a-gonna do this, you darn well should have a helper with a rope/bunch of clothesline, standing physically clear of you. If you get stuck on something and can't unclench, they're to throw the rope over you and pull you off. And if they're not happy with the idea of that job, then get an electrician in to do the work.

If they are testing the oulet on its own then the two hots could be fed from the same phase. Shouldn't be enough coupling to cause a false 120V reading.

 

[Tronguy]

If they are testing the oulet on its own then the two hots could be fed from the same phase. Shouldn't be enough coupling to cause a false 120V reading.

Yep, you got it.

Back in a galaxy far away had a problem like this, but not on city power. Had an LVDS (Low voltage, differential signal) being sourced from a driver on one circuit board; the pair of wires went through a connector on a backplane, across the backplane to another circuit board, through another connector, and onto a receiver device. The receiver device had, built-in, a 100 Ohm resistor across the wires.

Turns out that on the first backplane connector there was an open. Later investigation found Gunk (nobody ever admitted that their processes involved gunk) on the backplane pins. So, on the backplane, on the pins going into the second circuit board, there was an actual signal with respect to ground - but the voltage across the two wires was Zero.

This actually happened More Than Once, resulting in this (fairly expensive) shelf being totally replaced in the field and the whole business sent across a continent or two on its way back to the lab. So, there I was with a bright light and a macro camera taking pictures of fields of pins.. and what was this yellow, shellac-y looking stuff on that particular pin?

Weird things happen in manufacturing.

 

[mongo]

Yep, you got it.

Back in a galaxy far away had a problem like this, but not on city power. Had an LVDS (Low voltage, differential signal) being sourced from a driver on one circuit board; the pair of wires went through a connector on a backplane, across the backplane to another circuit board, through another connector, and onto a receiver device. The receiver device had, built-in, a 100 Ohm resistor across the wires.

Turns out that on the first backplane connector there was an open. Later investigation found Gunk (nobody ever admitted that their processes involved gunk) on the backplane pins. So, on the backplane, on the pins going into the second circuit board, there was an actual signal with respect to ground - but the voltage across the two wires was Zero.

This actually happened More Than Once, resulting in this (fairly expensive) shelf being totally replaced in the field and the whole business sent across a continent or two on its way back to the lab. So, there I was with a bright light and a macro camera taking pictures of fields of pins.. and what was this yellow, shellac-y looking stuff on that particular pin?

Weird things happen in manufacturing.

Got called back from a trip due to an assembly not working quite right. Turns out the clock cable wasn't connected. Chassis had a single ended to differential converter on the clock input so it could (mostly) run on any noise source...

 

[ATPMSD]

BTW, assuming the 14-50 outlet is a “new” install, as opposed to being there when the house was built, the electrical code requires a GFCI breaker.

 

[davewill]

Not related, but most breakers don’t allow a double tap either. 4th and 5th down.

Good catch. It looks to me like the "electrician" who installed this circuit probably removed two breakers to make room for the new double and just put the wires from those breakers on the two breakers above. I have to wonder if he even bothered to find out exactly what was on all those circuits. I wouldn't let this guy anywhere near my house.

 

[Fourdoor]

Good catch. It looks to me like the "electrician" who installed this circuit probably removed two breakers to make room for the new double and just put the wires from those breakers on the two breakers above. I have to wonder if he even bothered to find out exactly what was on all those circuits. I wouldn't let this guy anywhere near my house.

Yeah, notice that all the other wires are dirty, but the new wires for the 50 amp are clean, and the ones that are doubled up are relatively clean compared to the rest... looks like they were moved.

Keith

 

[Tronguy]

Got called back from a trip due to an assembly not working quite right. Turns out the clock cable wasn't connected. Chassis had a single ended to differential converter on the clock input so it could (mostly) run on any noise source...

Heh, and the last one on this topic.

Quartz oscillator, capacitor coupled to an ECL differential receiver with resistive DC bias on the + input of the ECL.

The - input of the receiver was filtered feedback from an integrator, rigged so the output of the receiver had a 50% duty cycle.

When first turned on, the quartz oscillator had to start, which took.. time. In the meantime, the integrator would force the voltage on the + terminal to be equal to the - terminal; with no hysteresis on the receiver, and being ECL, there'd be bursts of 500+ MHz random noise, feeding back through trace capacitances built into the board. Some of that would feed through that coupling capacitor into the output of the quartz oscillator, fouling up the insides of the oscillator, which then wouldn't start. And there it would stay, fouling up this Rather Large system.

I got asked to look at this, the complaint from the poor engineer being, "But if I touch it with a probe or my finger it starts working just fine! And if I unplug and plug the board back in, more than half the time it works just fine!" Without even going to the lab I asked to look at the schematic. Stared at it a bit, asked a few questions about operation, then the light dawned. Told the guy he needed to add a feedback resistor for hysteresis and it would Work Just Fine. The hysteresis would slow down the oscillation, lots, kill the high-frequency stuff, and the oscillator would then start, reliably.

He didn't want to believe me, but tried it and it worked. Cue a dead-bugged, thin-leaded, 20kOhm resistor added to the top of the board in manufacturing .

The joys of being a mixed signal engineer.

 

[mongo]

Heh, and the last one on this topic.

Quartz oscillator, capacitor coupled to an ECL differential receiver with resistive DC bias on the + input of the ECL.

The - input of the receiver was filtered feedback from an integrator, rigged so the output of the receiver had a 50% duty cycle.

When first turned on, the quartz oscillator had to start, which took.. time. In the meantime, the integrator would force the voltage on the + terminal to be equal to the - terminal; with no hysteresis on the receiver, and being ECL, there'd be bursts of 500+ MHz random noise, feeding back through trace capacitances built into the board. Some of that would feed through that coupling capacitor into the output of the quartz oscillator, fouling up the insides of the oscillator, which then wouldn't start. And there it would stay, fouling up this Rather Large system.

I got asked to look at this, the complaint from the poor engineer being, "But if I touch it with a probe or my finger it starts working just fine! And if I unplug and plug the board back in, more than half the time it works just fine!" Without even going to the lab I asked to look at the schematic. Stared at it a bit, asked a few questions about operation, then the light dawned. Told the guy he needed to add a feedback resistor for hysteresis and it would Work Just Fine. The hysteresis would slow down the oscillation, lots, kill the high-frequency stuff, and the oscillator would then start, reliably.

He didn't want to believe me, but tried it and it worked. Cue a dead-bugged, thin-leaded, 20kOhm resistor added to the top of the board in manufacturing .

The joys of being a mixed signal engineer.

Yep, mine was ECL too.

 

[RonAz]

Not a very attractive panel. Dust is conductive. Probably a 125 amp panel? No main beaker either. Looks like the house was wired with 12-14/3 with shared neutral. With two different gauges on one breaker, I wonder which one is protected? The neutral for 4 and 5 could get overloaded in this mess.
Myself, I would have turned this job down. I read where many have their panel upgraded when they buy an EV. Might be a good reason for this shown here.