Problem with Portable LED Message Center (Ground Fault)

[jeffpoit]

I'm having problems with a portable LED message center tripping a 20amp GFCI receptacle, but it never pulls more than 10.4 amps.

The problem lies in the inductive loads of the power supplies.

I've asked several experts, but to no avail. My question is, will some type of filter or UPS (Uninterruptible Power Supply) condition the load before it reaches the GFCI?
Read some of my conversations below....


Looking over the 2014 NEC, there's mention of LED drivers being grouped with other inductive loads such as ballasts, solid-state power supplies and transformers that deserve special consideration. I imagine some type of filter system(s) may help, but it's beyond my knowledge level on what kind, or the specifics on how to compute the filtering requirements... If you figure this all out, how about shooting me another email on the details... I believe you working in the future of all lighting.


Best regards,


Fred

Electrical Instructor

Contractors Institute

 

[dpc]

Have you tried a different GFCI receptacle? GFCI devices are extremely sensitive and nuisance tripping is certainly common with a lot of different loads. They are also susceptible to RFI. I suspect a cheap switching power supply is the culprit if this occurs with every GFCI outlet. You could also try increasing the physical distance to the GFCI. Does this gizmo require a GFCI outlet?

 

[jeffpoit]

It does not; however, it's on a mobile trailer and the NEC code requires outside receptacles to be GFCI. It runs fine on a standard receptacle. The power supplies are MEANWELL out of Taiwan. Is there any kind of conditioning filter that I could install between the load and the GFCI?

 

[dpc]

It's pointless to start buying power conditioning without some idea as to why the GFCI is tripping. This is the Ready, Fire, Aim school of troubleshooting. GFCI receptacles are a commodity item and I've found many bad out of the box. Before buying power conditioning, I'd buy a new GFCI recept if you haven't tried this already.

If you put in a single (not duplex) that is dedicated to this gizmo, it probably does not need to be GFCI. You could make it a twist-lock for good measure.

 

[jeffpoit]

Thanks. I have only tried the one GFCI on site and the other I purchased from Lowe's and tried at my shop. Are you saying that if we can lock access to the receptacle and dedicate it to this unit, then it should be acceptable to code?

 

[PeterKsiazek]

This is likely due to excessive leakage in the power supplies Y-caps (part of the EMI filter). IEC-60950-1 limits this current to 3.5mA (A GFCI should trip at 6mA)... but that doesn't mean a 'economical' power supply built to a price is going to actually meet this standard, even if they say it does! It is doubtful you can add a filter or power conditioning to limit this current. I agree with dpc that you could try a different GFCI, but if you have the equipment you can measure the leakage current, or, just contact the manufacturer.

 

[dpc]

There are some exceptions to the GFCI requirements for fire/burglar alarms. But this is for dwelling units. The other options is to hard-wire the device to the ac power without a receptacle, similar to a light fixture.

 

[stevenal]

How about plugging this thing into a listed isolation transformer sized appropriately, which in turn is plugged into the GFCI? No ground reference removes both the hazard and the tripping.

 

[jeffpoit]

Thanks stevenal, I will try the isolation transformer.

 

[dpc]

That should work, assuming the tripping is caused by actual ground current

 

[jeffpoit]

Is there anyway for me to detect the ground current before I buy a transformer?

 

[dpc]

It may be difficult, since it is probably not a nice 60 hz sine wave. It's possible, but probably not worth the trouble. I'd just hard-wire it and forget the receptacle connection.

 

[stevenal]

Hard wiring kinda defeats the whole portable on a trailer bit. And if this a listed cord connected device, it would be a violation to alter it.