New GFI 110v outlets blow out TECO VFD

[Ulma Doctor]

i replaced my GFIC outlet with a standard 15 amp wall plug to avoid any problems like this

 

[4GSR]

After the inspector leaves, change the GFCI plug out with a standard one. Just be sure to change it back if you sell the place.

 

[markba633csi]

I think Tim nailed it- it's the VFD's darn internal RFI filter that looks like a ground fault to the GFCI. Only other solution I could offer would be to use a large isolation transformer between the GFCI and the VFD. But, see if you can hardwire the VFD in or, use Ken's solution
I don't think adding another ground will help but you could try.
Mark S.

 

[rwm]

North Carolina only adopted 2014 NEC in 2016 (with amendments.) My entire house is out of code at this point. It was built to existing code at the time though. Point being, only you know when specific work was done and if it was compliant at the time it was done.
R

 

[Glenn Brooks]

Thanks all, looks like hardwiring the connection is the best option. FYI, this is a new circuit I am adding, ( one of two) so have applied for an electrical permit and can’t get away from passing a new inspection meeting the latest code requirements, e.g. the GFCI receptacles.

 

[Blackjackjacques]

Generally, most jurisdictions require GFCIs only in damp or wet spaces. Garages, bathrooms, un-finished basements, etc are usually classified as damp or wet spaces. Shops may not necessarily be classed as a wet or damp space. If there is a means such that the motor housing or enclosure can get wet - say condensation for instance then you want a GFCI. GFCIs are sometimes waived where the branch service is dedicated to a particular appliance. The interpretations for what constitutes "dedicated" can vary from jurisdiction to jurisdiction. In some cases the AHJ will accept a receptacle in immediate proximity to the equipment and labeled as such, in some it may be a screwy receptacle style and your appliance being the only item with a matching plug, and in some it means a hardwired pigtail. You can ask the AHJ and see what they will accept. Residential GFCI devices are Class A devices, meaning that they protect against electrocution as well as damage to equipment. Class A devices range from 4 mA to 254 mA of leakage, while industrial (Class B) GFCI devices are set to trip above 254 mA and do not provide protection from electrocution -- they only protect equipment. The AHJ should not normally permit Class B devices in a residential application where GFCI devices are invoked. As Tim and Mark points out, an RFI filter at the VFD can supply sufficient leakage to trip a GFCI. In fact, many lighting dimmer devices can also trip GFCI devices. An isolation transformer between the GFCI and the appliance (in your case the VFD) will thwart GFCI tripping as well as practically eliminate the shock risk - but they are pricey. AFCI devices only guard against arc faults and do not do what GFCI devices do. AFCIs will trip if connected to anything that sparks - say a motor using brushes for instance. AFCIs are usually required where a receptacle is in close proximity to combustible material - like drapes in a living room, etc. GFCIs work and have saved lives while I am not so persuaded for AFCIs. If you have a damp situation with connected equipment, you want a Class A GFCI device even if the AHJ says you do not need it.

 

[Eddyde]

So far, the fix seems to be, get the inspection signed off, then replace the da&n things with standard electrical outlets.

That is exactly what I would do .

 

[higgite]

Glenn,

The quote below is from the NFPA website, authors of the National Electric Code. Most municipalities that I’m aware of (certainly not all) who even have a code, usually rely on the NEC. Like Blacjjackjacques said, you may not be required to have GFCIs for your new circuits. Has the inspector said that you do? If so, have you asked him to point you at the written code or county requirement?

Tom

https://www.nfpa.org/Public-Educati...re/Electrical/Electrical-circuit-interrupters
“GFCI protection is required by the 2017 NEC for newly installed and replacement 15 and 20 amp receptacles on kitchen countertops, in bathrooms, outdoor areas, unfinished basements and crawl spaces, garages, boathouses, laundry areas, and within 6’ of sinks, bathtubs and shower stalls. GFCI protection is also required for certain appliances that have a history of being a shock hazard. Drinking fountains, vending machines, dishwashers and boat hoists are examples of appliances that require GFCI protection.”

Edited to address the right person. Sorry about that.



 

[jim18655]

NEC is the minimum code and municipalities can go above the minimum requirements. Some cities I've worked in required BX cable when Romex met the code standard for single family homes. No BX = failed inspection.

Remember, do what you want until there's a problem and the lawyers and insurance companies get involved.

I knew a guy that did maintenance of all types in industrial facilities. He serviced his oil furnace and had a fire that destroyed his house about 6 months later. The insurance and fire marshal determined the fire started in the furnace and held his payment up for over a year. He ended up suing to get his money. They wanted to know if he was "qualified" to work on his own equipment.

 

[JPMacG]

You could put a 1:1 ungrounded isolation transformer between the GFCI and the Teco. I think that might work, but I may have myself confused.