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Replacing an old noisy range hood is a great idea, new units are more efficient and much quieter.
Wiring a replacement range hood in an old building the electrical connection can be confusing since there are not enough wires to make the connection. Many buildings from the ’50s and ’60s do not have grounded circuits and will only have two wires connected to the old range hood.
A range hood does not have to be grounded if replacing an excising range hood and connecting to an exciting wiring circuit. While not required by code, it is recommended to install a ground fault circuit interrupter to protect people from electric shock in case there is a fault with the range hood.
While it is allowed by building code to replace a range hood without grounding it, it is quite hazardous if something were to happen with the range hood. Since most range hoods are made out of metal any loose wire inside can lead to an electric shock.
Will I Get a Shock if I Leave the Ground Unconnected
Unless there is something wrong with the range hood, a loose wire, or some other fault you will not get an electrical shock even if you don’t connect the ground wire.
Since the range hood is vibrating slightly when turned on there is a small risk of wires loosening up and hitting the metal frame of the hood. When this happens there is a serious risk for electrocution.
Fortunately, by installing a GFCI you can prevent serious harm even if the range hood malfunctions. I will discuss this more later.
GFCI – Ground Fault Circuit Interrupter
What About the Metal Sheath Around The Wires
Some wires have a metal conduit around the white and black wires. This can not be used as a ground unless there is a thin metal strip under the metal jacket.
How to Make it Safer
While it is OK to simply replace the range hood and stay compliant with building codes. It is always best to ground appliances that are designed to be connected to the ground.
Install A Ground Fault Circuit Interrupter
Installing a GFCI to the range hood circuit is almost always much easier than running a new wire that has a ground lead.
A GFCI will cut the power if there is a current leak. Make sure to place it somewhere easily accessible since if it trips it is necessary to press a button on the GFCI to turn the power back on. Be extra careful when doing this though, if it tripped this means there is a voltage leak somewhere.
Related article: Does a Bathroom Fan Need a GFCI
A GFCI will protect you from lethal electrocution, but you can still receive an electric shock from a malfunctioning appliance.
Pull New Wires From The Breaker Box
The best solution is to pull a completely new wire that has a ground lead. Depending on where your kitchen is located related to the breaker box this can be an easy job or a massive undertaking.
If you are taking on the job it’s wise to run at least one extra empty conduit. This way it is easy to add another wire if needed in the future.
Relevant Article: Who to Hire To Install a Range Hood
Let’s take a look at all the different ways a new cable could be installed. You will likely find a option that will work for you.
I guess you are wondering why to pull new wires when you could simply add an additional outlet to the existing countertop receptacles and be done with it. Unfortunately, this violates NEC 210.52(B)(2). You can find all the permitted ways a range hood can be connected here.
Under The Floor
If your house has a unfinished basemend or a crawlspace under the house then running a new wire is relatively straightforward and requires no drywall work.
Drill down two holes. One from the kitchen, straight down from the range hood if possible. The second from where the breaker box is located. Try to position the hole close to a wall and directly below the breaker box.
Snake the wire from the kitchen to the breaker box and connect everything. It is best if you have someone helping you to feed the wire. Otherwise you might have to make many trips between the basement/crawlspace and kitchen to free up the wire.
Make sure to use a metal conduit (amazon link) to protect the wires that are under the house from rodents.
While this can be done as a DIY job, the actual connection to the breaker box should be handled by a qualified electrician.
From The Attic
Running a new wire from the attic is somewhat more complicated. Depending on how much and what type of insulation there is and if you need to build a walkway to be able to access the kitchen and breaker box from above.
There might be more than a foot of insulation in your attic so make sure you get a very long drill bit. This makes it very easy to spot where the hole is drilled.
What I normally use in this case is a drill bit extender(amazon link) and a spade drill bit. Note that the drill bit must be larger than 3/8″ in order for the extension connector to fit through the drilled hole.
- Drill a hole up from the kitchen and breaker box while another person is up in the attic spotting where the drill comes up
- Remove insulation from where the holes are
- Feed a cable that is prefeed into a metal conduit up from the kitchen ceiling
- Run it across the attic and down to the breaker box
- Carefully seal any moisture barrier that was damaged and replace the insulation
- Have an qualified electrician make the connections
It is just as important to protect the wire from rodents in the attic as it is in the crawlspace. So it is best to use a metal conduit to make sure that the rat and mice don’t feed on your new cables.
Run a New Wire Under The Baseboards
If you are lucky and the breaker box is not far away it might be possible to run the wire behind the baseboards.
This does only make sense if the breaker box is very close, or there is no access from above or below. It is quite labor-intensive to run cables behind baseboards as a couple of inches of the drywall must be removed and holes drilled through the studs.
- Carefully pry away the baseboards. It is best to pry the first little bit with a sharp putty knife. This will cause the least amount of damage
- Cut the drywall. Baseboard height – 1/2″ This way it will be nicely covered up later*
- Drill holes for the conduit
- Snake the conduit through the holes
- Install nail guards over the holes (very important)
- Screw the drywall back
- Nail the baseboard
*if the baseboard is less than 3 inches wide, there is most likely not enough room to install the wire behind it.
Pull A New Wire Through A Existing Conduit
Open up the junction box behind the range hood and see if there is an empty conduit that you could use to snake a new wire to the breaker box. This is highly unlikely, but it’s worth a look since it will make the job much much easier.
If you are going to buy a wire puller make sure you get one that is ultra-low resistance(amazon link). Otherwise, it is impossible to snake the cable more than 20-30 ft.
Find a Ground Wire Nearby
While this is not code compliant, it will make the range hood safer. If you find a nearby junction box that has a ground wire, you can simply run a new ground wire from there. Make sure you run it in a conduit and not loose behind the cabinets.
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