8

I recently purchased an apartment in New York City built ~2006, and we started renovating the kitchen. After I unhooked the dishwasher (an older Bosch model) I found that there was only a hot and neutral wire attached to the electrical panel for the dishwasher.

I'm a little surprised this is allowed or up to code since the connection does not use a GFCI breaker, and there doesn't appear to be a ground wire. Is the metal cladding on the cable an acceptable ground?

I've attached a photo of the cable that was previously attached to the dishwasherenter image description here

14

That metal cladding is a valid ground path, provided it is connected properly to a metal box with either a ground wire from the breaker panel connected to the metal box or the metal box connecting to metal conduit back to the breaker panel. Any actual ground wires involved (e.g., if one comes out from the dishwasher along with hot & neutral) should be connected with a screw like this one into the metal box.

green ground wire

It doesn't have to be green, but it does have to have the correct type of threads in order to make good contact with the box.

As far as GFCI, that is relatively new for hardwired dishwashers - in most locations only since adoption of the 2014 NEC (if I remember correctly from another recent question).

2
  • Thanks! Is there any way (without opening up the walls) to safely know if the cladding is properly grounded? Would I need to connect the dishwasher to the cladding somehow?
    – lchi
    Jul 21 at 20:08
  • 1
    Not an absolute guarantee, but with the breaker off (for safety, because black wire is hot) use a multimeter to check resistance between the white wire (neutral) and the metal. It should be at most a few Ohms. As far as connecting to the dishwasher, the dishwasher will either have an integral metal box or have a hot/neutral/ground cable of its own. If it is a separate cable then you should have (or will need to install) a metal junction box and if the two cables are properly connected to that box then it will complete the ground path. Jul 21 at 20:50
10

Congratulations on moving to the big city.

Now, get familiar with big-city electrical. You'll see a lot of the metal conduit wiring method. This is an industrial-grade wiring system that is required where safety matters more, because more lives or property are at stake. They typically require it in multiple occupancy buildings, to reduce electrical fires.

In this type of installation, the metal conduit shell is often the ground. This is better than ground wires most of the time. Flexible conduit or metal-clad cable can be "hit or miss" as to whether it is a valid grounding path, however.

Another thing about that is that DIY electrical is not necessarily on the menu.

  • Certain large cities prohibit DIY electrical.
  • You're one unit in a larger building, and you don't own the land, the roof, or the building. That means there is an owner or HOA, and you must follow their rules.
  • Because you are in a multiple occupancy, all work must be done by a licensed electrician because of the potential danger to other occupancies if the work is botched.
  • If you are renting, the work must be done by a licensed electrician, for above reasons and also to prevent landlords from doing shoddy DIY work that endangers the tenant (so this would be true even in a standalone single family home).

Skipping out on the permit process isn't on the menu either. Again, you must go through both the city and the owner/HOA and/or landlord.

2
  • Thanks for the informative response Harper - DIY electrical is definitely not on my list of things to do. To clarify - we're trying to replace an older Bosch model with a newer one (bosch-home.com/us/productslist/dishwashers/top-controls/…) and it looks like the old one was hard-wired in. Is the dishwasher installation unsafe (using existing connections) to do without a licensed electrician?
    – lchi
    Jul 21 at 20:18
  • 2
    I would say safety requires knowing how to handle the wiring methods that are present @lchi. An electrician may not be needed, but certainly an installer who knows how to execute the wiring methods correctly. I haven't seen anyone here describe properly what to do with that ground wire. Jul 21 at 20:39
4

Judging by the paper inside the flex you are probably dealing with Type AC Armored Cable (installation covered by NEC Article 320). My guess is if you remove the connector you will find an "internal bonding strip of copper or aluminum in intimate contact with the armor for it's entire length." (NEC 320.100).

If the connector is Listed (UL/CSA/ETL) for use with Type AC cable then the jacket satisfies the grounding requirement. Unfortunately it is a little hard to identify brand and model you have, but normally that style is Listed for Type AC.

Depending on local amendments to the NEC you won't likely be required to provide GFCI protection for replacing the DW, but NEC 250.114(3)(b) does specify an approved ground is required, a GFCI in place of a ground is not acceptable.

Edit: Armor Clad from the exterior appears similar to Type Metal Clad, but MC (and hospital grade AC) will have a green insulated ground inside the jacket. MC will also have plastic in place of the fire retardant paper. Here is a document detailing differences and manufacturers instruction for terminating. https://www.afcweb.com/wp-content/uploads/2015/06/mc-ac-installation.pdf

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.