I have a customer (restaurant) that has an outdoor bar. It is fully-covered, but everything electrical is wired as if it is a wet location. The dishwasher is cord connected to a standard 5-20 GFI receptacle that trips fairly consistently. They replaced the entire dishwasher and the new one does the same thing.

I'd like to hard-wire the thing with a take-off box and a short piece of liquid-tight flex, but the appliance people are insistent that it remain connected via plug and receptacle.

If I have to do this, I'd like to remove the GFI receptacle from the equation by using an L5-20 "Twist Lock" receptacle and plug with an in-use cover.

Does anyone have any heartburn about doing it this way?

NEC prohibits your work around, AFAIK.

It's the receptacle that's probably burnt out.

They go, too, you know.

Filthy spray condenses within its workings -- presto -- you've got a troubled washer.

I'd ALWAYS replace the GFCI receptacle -- in commercial use -- when such a serious equipment swap is underway. That way the customer has a clean slate.

The first thing I would do is figure out why the GFCI is tripping. Do they hose this place down? Is rain blowing in?
Are there critters nesting inside the dish washer?

Otherwise you are asking, how close is it to the sink (<6'), is this a "kitchen" and is it really "outdoors"? 210.8(B) does not say NEMA 5-15, it says 15 & 20a 125v receptacle. Twist lock does not change that.

When they replaced the dishwasher, did they use the same (old) cord. The paper in some SJ type cords will wick up moisture and cause GFCI to trip. Replace cord with an SO cable or one that has no paper filler.

There are five GFI receptacles within reach of this dishwasher an it trips every one of them consistently. I don't see the receptacles themselves as being the culprit. Yes, it appears that they reused the original cord on the new washer, so the cord could be causing this issue. It is SO cord though. They did have their maintenance man in that morning with the power washer to clean the entire bar area, so he may have gotten a bit carried away with it.

At this point, I have told the customer to have their appliance people come out to investigate further.

My bet is hosing the place down is getting water where it shouldn't be. That is common in commercial kitchens. I am not sure how you stop it.

Ed:
Curious as to how the cord on the DW can reach the five other adjacent receptacles? 422 limits the cord to a length 3' to 4' max.

If the GFI recept is doing its intended job, then the DW or the cord is the culprit.

Removing the GFI IMHO would expose you to a liability you do not want.

John, there are five WP GFI receptacles all clustered together for them to use for outdoor cash registers, printers, etc. I'm in agreement with everyone though; the GFI is doing what it is supposed to do, so they will need to call in the appliance repair people. This is why they pay for their maintenance contract.

This may be as simple as figuring out where the water is getting into the electrics and sealing or shielding it.

Woodhead (Molex) is the specialty player in wet receptacles/ kitchen washdown environments.

http://www.molex.com/woodhead

This situation may require abandonment of GFCI receptacles -- to be replaced by GFI circuit breakers and Woodhead washdown cord caps.

Given enough time, you can be assured that filth has invaded the inner workings of ANY GFCI receptacle on the market. They are not designed for sloppy soap/ water jets.

I'd be VERY surprised if the new equipment is the source of the trip.

BTW, there's no way the new unit has a bonding between the neutral and the grounding conductor, is there?