Unfamiliar territory: working in the kitchen

Top on my "honey do" list this week is replacing sink disposal unit in the kitchen sink. Replaced an old hard-wired unit that is activated by wall switch with one that has a 3-prong power cord attachment. To hook up power to the new unit, do I simply need to splice the two cords together?

Replacement unit: Waste King L-3300 Legend Series 3/4 HP Continuous Feed Operation Waste Disposer

Quote from Ram|bunc|tious : Top on my "honey do" list this week is replacing sink disposal unit in the kitchen sink. Replaced an old hard-wired unit that is activated by wall switch with one that has a 3-prong power cord attachment. To hook up power to the new unit, do I simply need to splice the two cords together? Replacement unit: Waste King L-3300 Legend Series 3/4 HP Continuous Feed Operation Waste Disposer

Do you want it to be up to code or work for cheap?

What you are supposed to do is install a junction box and an outlet under the sink. It ends up giving you the exact same results as just splicing the wire, but a bit more work and a touch more expensive. But you can add a GFCI outlet if you want / don't have one on that circuit.

Even though the new disposal has a cord, it can be hardwired directly. Read the manual, they should talk about this. Basically if you open it up near the cord you should be able to disconnect the cord and connect the wires.

DO NOT splice NM-B romex to a cord outside of a junction box, and avoid doing it in a junction box!

Hopefully there's a junction box on the wall and a flexible metal of plastic conduit / metal sheathed cable that leaves the wall and connects to the disposal. In some cases romex may just connect to the disposal with nothing around it, this is less desirable and is a little bit of a grey area in the code.

If you want to leave the cord, the obvious option is to install an outlet to connect it to, this is required to be a GFCI if you install a duplex receptacle (two outlets, a standard outlet), if you install a single outlet it wouldn't have to be gfci (these aren't always easy to find locally).

It isn't expensive to do this right and there's just no excuse.

I recently did the same thing and used the existing wiring and connected it to the new disposal. Listen to the above posts...Do Not splice it.

Quote from jkee : Even though the new disposal has a cord, it can be hardwired directly. Read the manual, they should talk about this. Basically if you open it up near the cord you should be able to disconnect the cord and connect the wires.

No manual

Quote from jkee : DO NOT splice NM-B romex to a cord outside of a junction box, and avoid doing it in a junction box! Hopefully there's a junction box on the wall and a flexible metal of plastic conduit / metal sheathed cable that leaves the wall and connects to the disposal. In some cases romex may just connect to the disposal with nothing around it, this is less desirable and is a little bit of a grey area in the code. If you want to leave the cord, the obvious option is to install an outlet to connect it to, this is required to be a GFCI if you install a duplex receptacle (two outlets, a standard outlet), if you install a single outlet it wouldn't have to be gfci (these aren't always easy to find locally).

Hmm... new outlet seems to be way to go. Old power cord disappears behind cabinetry, cannot trace it.

Quote from jkee : It isn't expensive to do this right and there's just no excuse.

It cuts into Happy Hour?

Quote from Ram|bunc|tious : Hmm... new outlet seems to be way to go. Old power cord disappears behind cabinetry, cannot trace it.

When was the property built?

Describe the old power cord. Is it romex? is it armored cable? is it a type of conduit? Are there any markings on it and what are they? A picture always helps.

The best approach depends on what you're dealing with.

Quote from jkee : When was the property built?

~18-20 years ago.

Quote from jkee : Describe the old power cord. Is it romex? is it armored cable? is it a type of conduit? Are there any markings on it and what are they? A picture always helps. The best approach depends on what you're dealing with.

Really couldn't tell you what type it is ... does this pic help?

Looks like just Romex to the disposer...not installed properly to start with.

First, find the circuit breaker turn it off! Turn on the disposal to be sure.

Then either, cut out drywall (better option) so you can install an old work 1 gang box [homedepot.com]. You may want to score the surface of the drywall with a utility knife fairly deeply and start with a pair of pliers to break some of it out before you switch to a hand drywall saw to make it easier to avoid the wire and pipes. Don't cut the hole too big!
-OR-
Install a 1 gang outdoor box with trade size 1/2" knockouts [homedepot.com] on the surface of the wall (there are dimples you can use a punch on to expose mounting holes, put a screw into the stud and use a drywall anchor for the other) mount it after the wire is installed. Thread an NM clamp [homedepot.com] into the back of the box pull the wire in and tighten it.

Once you've got wire in a box that's mounted, ground the box if you used a metal box and then install a GFCI receptacle or a single outlet [homedepot.com]. Some people would install an outdoor in use cover on the box which isn't a bad idea, but that's your prerogative.

Quote from repitall : Looks like just Romex to the disposer...not installed properly to start with.

Quote from jkee : First, find the circuit breaker turn it off! Turn on the disposal to be sure. Then either, cut out drywall (better option) so you can install an old work 1 gang box [homedepot.com]. You may want to score the surface of the drywall with a utility knife fairly deeply and start with a pair of pliers to break some of it out before you switch to a hand drywall saw to make it easier to avoid the wire and pipes. Don't cut the hole too big! -OR- Install a 1 gang outdoor box with trade size 1/2" knockouts [homedepot.com] on the surface of the wall (there are dimples you can use a punch on to expose mounting holes, put a screw into the stud and use a drywall anchor for the other) mount it after the wire is installed. Thread an NM clamp [homedepot.com] into the back of the box pull the wire in and tighten it. Once you've got wire in a box that's mounted, ground the box if you used a metal box and then install a GFCI receptacle or a single outlet [homedepot.com]. Some people would install an outdoor in use cover on the box which isn't a bad idea, but that's your prerogative.

Thanks guys, will follow the advice and post pictures. Feel free to mock them, at least I'm trying to do it right!

Quote from Ram|bunc|tious : No manual

http://66.39.51.245/wasteking/com...0Guide.pdf

once you have pics it will be easier but the box and everything else should be pretty easy you can use bigget box with a single outlet in it if you are not used to squeezing wires into a box..

Also it seems that GFCI is not recommened for garbage disposals

http://homerenovations.about.com/...eccode.htm

but other say different

http://www.electrical-contractor....posal.html

For the safety factor I would say go for it but buy a quality one.

GFCI / No GFCI is a debatable subject, nuisance tripping isn't as likely to occur today as it might have been a few decades ago. As far as code is concerned, if you install a duplex outlet you need a gfci; If you install a single outlet you don't. If you hard-wire the disposal you don't need a gfci either.

Quote from jkee : GFCI / No GFCI is a debatable subject, nuisance tripping isn't as likely to occur today as it might have been a few decades ago. As far as code is concerned, if you install a duplex outlet you need a gfci; If you install a single outlet you don't. If you hard-wire the disposal you don't need a gfci either.

I wasn't able to intentionally make GFCIs nuisance trip with things like motors, old-style desktop fluorescent lamps, and even a super-cheap Montgomery Ward welder, and at least one of those GFCIs was an ancient design from the 1980s. I suspect the time delay built into them prevented nuisance tripping, and UL safety standard 943 allows a 6-second delay when the leakage current is very low, around 5-6mA.

UL 943 vs. National Semiconductor LM1851 ground fault interrupter controller: