LED with dimmer = nuisance tripped breaker?

[Citation]

OK, asking for a sibling. I've done a bit of web searching which suggests this might be a thing so I thought I would ask here. I'm describing what has been described to me so forgive me if details aren't there.

My brother asked about a circuit that was having trouble with breakers tripping. Not sure of the exact type but it's a 15A breaker in a home from the 70s. The breaker isn't a GFI or other more advanced type.

I'm assuming that for some reason the lights and a wall outlet in some room are both on this breaker. The lights are LED on a dimmer. When the LED lights are on using the printer trips the breaker.

Per a clamp meter (likely a UT-210E I suggested), the lights draw the following:
0.04A when off, .164A at 50% bright, .504A at 100%.

The printer draws 6.5-6.7A.

Thus we should have plenty of overhead here.

To test the circuit, bro tried a hair drier, 1484W (presumably measured with his Kill-O-Watt). No trip. Then he tried running it at low (714W, so guess 6A) and was able to print. So that would put the circuit at around 13A.

Next he ran the drier at low and the lights at low, no trouble. Turn the lights to high -> pop.

So somehow the way the LED+dimmer loads the circuit is causing a trip when the rest of the load is about 6A.

Anyone know why or how to best address the problem? Just get a different dimmer or different breaker?

Thanks

 

[Miss the Pontiacs]

I would not put a dimmer on a light that shares the voltage with an outlet for starters. Is the dimmer LED compatible? Maybe try just a plain old off/on switch and see what happens.

 

[wyliesdiesels]

OK, asking for a sibling. I've done a bit of web searching which suggests this might be a thing so I thought I would ask here. I'm describing what has been described to me so forgive me if details aren't there.

My brother asked about a circuit that was having trouble with breakers tripping. Not sure of the exact type but it's a 15A breaker in a home from the 70s. The breaker isn't a GFI or other more advanced type.

I'm assuming that for some reason the lights and a wall outlet in some room are both on this breaker. The lights are LED on a dimmer. When the LED lights are on using the printer trips the breaker.

Per a clamp meter (likely a UT-210E I suggested), the lights draw the following:
0.04A when off, .164A at 50% bright, .504A at 100%.

The printer draws 6.5-6.7A.

Thus we should have plenty of overhead here.

To test the circuit, bro tried a hair drier, 1484W (presumably measured with his Kill-O-Watt). No trip. Then he tried running it at low (714W, so guess 6A) and was able to print. So that would put the circuit at around 13A.

Next he ran the drier at low and the lights at low, no trouble. Turn the lights to high -> pop.

So somehow the way the LED+dimmer loads the circuit is causing a trip when the rest of the load is about 6A.

Anyone know why or how to best address the problem? Just get a different dimmer or different breaker?

Thanks

What type of printer? Laser or inkjet?

I would not put a dimmer on a light that shares the voltage with an outlet for starters. Is the dimmer LED compatible? Maybe try just a plain old off/on switch and see what happens.

Huh? why not?

Lights and outlets share circuits all the time without issue.

 

[cybrdyke]

Is the dimmer LED compatible?

It could be this ^^^
Not all dimmers are compatible with LEDs. Even dimmers that are compatible with SOME LED's might not be compatible with others. Older dimmers definitely aren't and will smoke an old dimmer. Your breaker could be trying to tell you this.
CD

 

[Citation]

Just talked with my brothers so I have a bit more information.

I believe the printer is a laser printer.

I asked about the shared circuit between lights and outlets as I assume this isn't best practice. He said this was done as part of work when an addition was added to the house. The wiring comes off a new (~ 5 years old) sub panel. The can lights were newly installed, not sure if the outlets were as well.

The dimmer is a smart dimmer (wifi enabled) so I'm assuming it was designed with LEDs in mind. I asked about temporarily changing it out for a dumb switch. It's possible but access makes this difficult. He does have a similar switch in a different part of the house so he is going to try the same experiments on that circuit.

The circuit that is tripping has 6 can lights. He is going to try pulling the lights and replacing them with a different type to see if the problem is solved by changing the bulbs themselves.

 

[Jim greengo]

Just talked with my brothers so I have a bit more information.

I believe the printer is a laser printer.

I asked about the shared circuit between lights and outlets as I assume this isn't best practice. He said this was done as part of work when an addition was added to the house. The wiring comes off a new (~ 5 years old) sub panel. The can lights were newly installed, not sure if the outlets were as well.

The dimmer is a smart dimmer (wifi enabled) so I'm assuming it was designed with LEDs in mind. I asked about temporarily changing it out for a dumb switch. It's possible but access makes this difficult. He does have a similar switch in a different part of the house so he is going to try the same experiments on that circuit.

The circuit that is tripping has 6 can lights. He is going to try pulling the lights and replacing them with a different type to see if the problem is solved by changing the bulbs themselves.

Put a regular switch on there and see what happens.

 

[Chucktin]

504 amps draw for LED lights?? Surely there's a decimal point missing there.

I have to agree with all the above. A LED dimmer is not the same as a dimmer for incandescent lamp circuits.
Also I have notice recommendations that Laser printers not share a circuit as the heating element draw can be more than a household circuit provides. (Obviously "can" and "provides" are the weasel words).

 

[Chucktin]

Okay I misread the post - 0.504 amps at 100%, my mistake!

 

[wyliesdiesels]

Yeah laser printers can draw a lot of current

Are you sure the laser printer is not cycling when the breaker is tripping

 

[Citation]

The combination of last printer printing+lights on full (which may mean the dimmer is a red herring) causes a trip. I was wondering about inrush current but I assume the lights are on first rather than lights are turned on while printing.