Dishwasher turning on and off when electric car charges

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T74

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Location
MA
Customer has a dishwasher turning off and back on when they charge their Tesla. Tesla Charger runs at 48 amps and there is a 200 amp service--both of which I installed.

Found a loose ground on the receptacle of the dishwasher but that didn't seem to fix anything.

Voltage went from 120 before charging to 118 during charging.

Still possible that there is not a correlation. customer is going use the 120 volt cord for a week or so to check if it keeps happening

Anyone have thoughts or run into something like this?
 
Dennis Alwon

Dennis Alwon

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If the drop is 2 volts that should not make the dishwasher cut off. I was thinking some loose connection. Does it only happen when the Tesla turns on? Did you test the dishwasher running when the Tesla was charging? That is what I would do and see if it really is cutting off.
 
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wwhitney

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Not sure if it applies to Teslas, but some on board car chargers (the hardware on the car itself) are quite noisy electrically. Not sure why that would affect a dishwasher, but it certainly has disrupted powerline communications or led to mechanical noise at breakers/panels. I guess even if Teslas in general don't have that problem, a partial failure in the on board car charger could cause electrical noise.

Cheers, Wayne
 
kwired

kwired

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Location
NE Nebraska
wwhitney said:
Not sure if it applies to Teslas, but some on board car chargers (the hardware on the car itself) are quite noisy electrically. Not sure why that would affect a dishwasher, but it certainly has disrupted powerline communications or led to mechanical noise at breakers/panels. I guess even if Teslas in general don't have that problem, a partial failure in the on board car charger could cause electrical noise.

Cheers, Wayne
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Most harmonics in a dwelling are from low level power devices, where the EV charger is a pretty significant load.

Been a while but I've seen in a industrial plant where that one large VFD causes problems in several places throughout the plant because of harmonic currents, yet the smaller drives scattered around don't give those sort of issues.
 
kwired

kwired

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augie47 said:
Is it possible a surge suppressor could help ?
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If the same thing that happens with some those large VFD's (though modern ones have better filtering built into them) the surge suppressor would constantly be clamping some current so to speak. Better would likely be a line reactor between the harmonic producing load and everything else?
 
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petersonra

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Northern illinois
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T74 said:
Customer has a dishwasher turning off and back on when they charge their Tesla. Tesla Charger runs at 48 amps and there is a 200 amp service--both of which I installed. It seems unlikely the charger could affect the dishwasher. have you seen this happen?

Found a loose ground on the receptacle of the dishwasher but that didn't seem to fix anything. Does not seem like something that would matter much as far as the dishwasher working.

Voltage went from 120 before charging to 118 during charging. I can buy the voltage dropping a hair when the tesla charger is on but it seems unlikely the little bit of voltage change matters any to the dishwasher.

Still possible that there is not a correlation. customer is going use the 120 volt cord for a week or so to check if it keeps happening I am not sure what you mean by this.

Anyone have thoughts or run into something like this?
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I suppose it is possible that the electronics module in the dishwasher is somehow being affected by electrical noise generated by the charger. Best bet would seem to be to put an RFI filter on the charger receptacle or the dishwasher circuit and see if the problem goes away once you personally verify that this is what is really happening.
 
kwired

kwired

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Location
NE Nebraska
petersonra said:
surge suppressors only deal with surges. it seems unlikely that a battery charger would generate surges large enough to trigger any surge protector.
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kwired said:
If the same thing that happens with some those large VFD's (though modern ones have better filtering built into them) the surge suppressor would constantly be clamping some current so to speak. Better would likely be a line reactor between the harmonic producing load and everything else?
Click to expand...
True, the harmonics would need to also need to increase voltage before the surge suppressor would even think about doing much of anything.

What I had in my mind was a situation once encountered with a large VFD where the harmonics created what was basically sort of a short circuit in power factor correction capacitors on motors that were not a part of the harmonic producing drive. We fixed that problem with line reactors on the offending drive.
 
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petersonra

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Location
Northern illinois
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engineer
kwired said:
True, the harmonics would need to also need to increase voltage before the surge suppressor would even think about doing much of anything.

What I had in my mind was a situation once encountered with a large VFD where the harmonics created what was basically sort of a short circuit in power factor correction capacitors on motors that were not a part of the harmonic producing drive. We fixed that problem with line reactors on the offending drive.
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do dishwashers have drives these days?
 
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tthh

Senior Member
Location
Denver
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Retired Engineer
Tripplite makes some devices that are combo surge and filter. Might want to try that.
 
kwired

kwired

Electron manager
Location
NE Nebraska
petersonra said:
do dishwashers have drives these days?
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I was comparing a high harmonic currents producing item to another potential high harmonic currents producing item and the interference it may cause with electronically controlled items, which most dishwashers tend to be anymore.
 
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