Wiring Kitchens
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• Kitchens require two dedicated 20 amp small appliance circuits. nec 210-52(b2-3)Only outlet receptacles in the dining rooms and kitchens can be connected to these two circuits. No lights, no built-in appliances of any kind can tap into the two dedicated 20 amp small appliance circuits
  
• Evenly distribute the electrical loads between the two dedicated circuits nec 210-11(b).. You can alternate each successive receptacle on the wall between circuit #1 and #2 or divide the circuit into one half the kitchen for each circuit. planning kitchen loads.
  
• You can ire the two dedicated circuit using (2) 12-2 romex wires or (1) 12-3 romex wire. If you choose to use 12-3 you must have a common tie circuit breaker that turns off both circuits if one of them trips.

• Counter tops wider than one foot must have an outlet 210-52(c)(1)

• Receptacle outlets must be placed on counter tops every four feet
  A coffee pot with a 2' cord must reach a receptacle no matter where it is placed on a counter top. When two countertops meet at ninety degrees the coffepot might reach everywheren but there might be four and one-half feet linerly beteen outlets. Here, use the four foot rule strictly as measured across each wall. A 5 foot counter must have (2) outlets and a 6 foot counter must have at least (3) outlet receptacles. 210-52(a). more info
• nec 210-52(b)3(c)5.Receptacles cannot be placed face-up on the counter.nec
  
• Countertop receptacles cannot be mounted on the wall higher than 18" from the surface of the countertop. nec 210-52(b)3(c)5.
  
• Ground fault interrupters must be installed on all counter receptacles
  in a kitchen. Outlets for stoves and refrigerators are generally not
  placed on GFCI's.
  
• In some cases countertop outlets including peninsular and island countertops can be placed in the bottom of cabinets no more than 18" high (1996 nec) or (20" high 2001nec). nec 210-52-c-5 (confirm this with your inspector) . In other cases outlets can be mounted up to 6" below the countertop with an extension in the code allowing 12" below the countertop. exceptions nec 210-52)(c)(5)
  
• Counter tops on kitchen islands must have at least one outlet where counter top
  has an overhang less than 6" 210-52 (c)(5) more info
  .
• Island and peninsular countertops must have an outlet receptacle
  
• Island countertop outlets cannot be lower than 6" from island top or 12" If there is a cabinet above the countertop in which a receptacle ca be placed you cannot mount a receptacle on the face of the lower cabinet lower than 6" handicap exceptions and others 210-52)(c)(5)
  
• Countertop that has receptacles mounted below the surface cannot protrude more than 6" over the cabinet base. nec 210-52 c-5
  
• Kitchens with disposals, dishwashers, compactors, sink insta-heaters, and ice makers may be required by the local inspector to each have dedicated 20 amp circuit. Otherwise the code allows any general purpose circuits to be used if the the power consumed by the individual appliance does not draw more than 50% of the circuits load. A 900 watt disposal draws less than the 2400 watts available on a 20 amp circuit while most dishwashers draw more than 50% of the 2400 watts and therefore needs a dedicated circuit. If you do not know the loads wire dedicated 20 amp circuits to each appliance nec 210-23(a) Check with your inspector. The rule of thumb is to use dedicated circuits
  
• Counter microwave can plug into countertop receptacles. If the microwave Anchor
  is built-in you must add another 20 amp dedicated circuit.nec
  
• The refrigerator can have a dedicated 15 or 20 amp circuit nec of the single outlet receptacle on that circuit is rated to that circuit nec This means that if it is a 20 amp circuit then a special 20 amp receptacle will be needed. Circuits with two or more receptacles do not fall under this rule.nec
  
• The receptacle loads must be evenly distributed in the room and on the countertops. Some local inspectors require the electrician to alternate each successive receptacle between the two 20 amp small appliance circuits. nec
  
• GFCI not required for refrigerator, compactor, disposal, or dishwasher. 210-8(a)6 

• Light switches must be placed at every entry to a kitchen.
  
• Lights cannot be connected to any of the kitchen outlet circuits nec
  
• Three and four-way switches must be used at multiple entry and exits to the kitchen
  
• The nearest switch at every entry (in a bank of switches) must operate the
           main lights.
• Outlet receptacles must be installed within six feet of each side
  of any door leading outside.   More info & drawings
  
• Unobstructed wall space not associated with counter tops greater
  than two feet in width must have an outlet. Measure wall distance around corners.
  nec 210-52-a-2 More info & drawings

• Unobstructed kitchen wall space must have an outlet every six feet. Start measuring at door entry or exit on both sides for 6' measurement 210-52 (a)1. These outlets cannot be any higher off the floor than 5'6" 210-52 (a)1-2.
  
• Stove ventilation fan circuit must be separate from the kitchen
  receptacle circuits
  
• You cannot install a circuit breaker box in a cupboard, or behind
  and over a kitchen appliance.  More info
  
• A wall mounted electric clock can be connected to the small appliance circuits 210-52(b)(2)exception 1
• Built-in appliances and areas inaccessible to small appliances are not to be part of the small appliance circuits. Read carefully the details in the NEC code. 210-52(c)5 under receptacle outlet location.
  
• You cannot install an outlet receptacle face up on a countertop
  nec 210-8-a-7.
  
•  You can use more than two dedicated circuits in a kitchen for outlets. 20 amp for microwave, 15 or 20 amp circuit for refrigerator.nec 210-52-3(b)1.
  
•  A countertop gas stove, or freestanding gas stove can be plugged into the dedicated circuits.  210-52(b)(2) exception 2
  
• Separate kitchens, even adjoining must have two dedicated small appliance circuits
  nec 210-52-b-3.
  
• Baseboard heaters with receptacles mounted in them can count as wall space receptacles but the heater must be connected to a dedicated circuit and the receptacle must be connected to one of the small appliance circuits. Electric wall heaters with an included receptacle are allowed by the nec, however, if not there must be a receptacle on either side, not below the heater. nec 90-7, 110-3(b), 424-9, 210-50(b). If you install a baseboard heater the wire you use must carry 125% of the nameplate current rating of the eater i.e. if the baseboard is 18 amps multiply 18 X 125% to get 25.5 amps thus you would need # 10 wire to connect the heater on a dedicated circuit to the sub panel.
  
• The kitchen is considered a habitable room when reading and interpreting the nec codes nec 210-70(a)(1)
  
• The dining room is considered to be an extension of the kitchen according to the nec 210 53b(3)c. If there is a countertop in the dining room it must have the loads evenly distributed between the two dedicated small appliance circuits nec 210-11(b). All receptacles on the walls must be connected to the small appliance circuits and they must be spaced every 6" and on wall greater than 2' in width. Sliding doors do not count as wall space.
• Refrigerators can have their own dedicated 15 or 20 amp circuit nec 210--52-3(b)1.
• Floor receptacles to satisfy the wall space requirement for outlets (not the countertop outlets) shall be place 18" or closer to the wall in the floor. nec 210-52(b)3(c)5.
• Maximum number of outlets nec 220-3(b)9. 3 watts/sq ft. Maximum load allowed on a 20 amp circuit is 20% of its rating or 16 amps, and for a 15 amp circuit 20% of its rating or 12 amps. nec 210-21Bb)2.
• Substitution a three prong outlet on a two prong, 2-wire circuit can be done if you use a GFCI on that circuit and clearly label all other outlets it feeds with a GFCI label nec 210-7(d).-3(b)
• The maximum height you can place a switch on a wall is 6'7". nec380-8 Switch plate must fit flush to the wall nec 380-10(b).
• No splices allowed concealed in the walls nec 424-40.
• Under cabinet receptacle outlet strips. Talk to your inspector. If the strips are UL listed in the White Book they can probably be used in place of wall mounted receptacles. The problem here is that the strips can be removed later leaving the walls without adequate outlet receptacles. Outlets are placed in the bottom of kitchen cabinets on islands and peninsular countertops but they are firmly built in. Inspectors have specific times of the day in which they take calls from the public. Get their name, write it down, and leave yours if you can.
  
• This web site is for use by competent people who have mechanical and electrical skills. Read and verify the subject matter here using other sources. National electric code reference numbers are given to you in an attempt to minimize any errors that may occur in the writing of these web pages.

Distance rules

• Switch and outlet receptacle distance rules

  	Outlet Receptacles
  6" rule	An outlet on the face of the kitchen counter lower cabinet cannot be greater than 6" below the countertop.
  12" rule	The outlet on the face of the lower cabinet can be 12" if there is not an upper cabinet within 18" of the countertop in which to place an outlet in the bottom of the cabinet . The code allows 12" if the owner is handicapped.
  12" rule	Countertops wider than 12" must have a receptacle. As a rule of thumb 9" provides a more user friendly kitchen for a coffee pot.
  18" rule	A receptacle can be placed in the bottom of an upper cabinet within 18" of the countertop. 1999 nec code.
  20" rule	A receptacle can be placed in the bottom of an n upper cabinet within 20" of the countertop. 2002 nec code.
  24" rule	Wires cannot be run together through joists and studs more than 24"
  2' rule`	A small appliance with a 2" cord must reach an outlet when placed anywhere on the kitchen countertop. Even though you have two foot reach the linear distance between outlets when two walls meet should be 4 feet or less.

More info: See link placing outlets, and placing switches       

• When wiring the disposal and dishwasher with a 12-3 wire make sure the white (neutral) wire is firmly fastened to the neutral bar at the subpanel. If the white wire comes loose the dishwasher motor will burn out when the disposal is turned on at the same time the dishwasher is turned on. If you have spliced the 12-3 wire anywhere along its length be sure the wires are joined in a professional manner.
  
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• Carefully make-up the ground connection inside the garbage disposal. When plastic water hoses and drain pipes are installed years later, an internally shorted disposal will electrify the metal parts of the sink. Thus, touching the drain flange and the water faucet at the same time will induce a shock.
  
• When working around copper water pipes, remember a "hot wire" touching the pipe can easily puncture the pipe. Also: Remember to locate any new outlet receptacles near the bottom and to the side of the drain pipes. If you place the outlet in the line of sight someone could electrocute themselves reaching their arm over the pipe and touching a hot wire.
  
  
• Consider using adjustable plastic boxes for countertop receptacles. An electrical inspector can have you reset the boxes if they are not within a quarter of an inch of the surface of the wall. If you have set tile or granite as the backsplash this could be costly. Recheck wiring in walls very carefully where tile and granite are to be used.
  
  
• When setting outlet boxes along a countertop do not measure the height for the box off the floor. Use a level to set a level line or if this is not possible measure the heights off the ceiling. Many floors are un level. When cabinet makers install cabinets they set the counter level, not off the pitch of the floor.It helps to set the line of outlets level in case you ever want to install tile. The line of grout will reveal any differences in the height of the receptacles.
  
  
• Install nail plates over wires that pass through stud in kitchens where cabinets are to be installed. Cabinet installers use 3" screws that can easily pierce wires running through studs. If possible run your wires in the space between the bottom of the dish cabinets and the countertop.
  
  
• Wood drilling bits can drill through galvanized water pipe particularly if the tip of the bit is hardened to cut through nails in studs. When drilling through a wall top plate in to space such as an attic do not push the drill more than an inch about the top of the plate. These drill bits can chew up wire and pipes faster than a person can control a drill.
  
  
• Nail plates placed over wires to protect them from nail gun nails do not stop the nails. When an earthquake shear wall is being installed make sure all the wires are drilled in straight lines so that the installer can mark the plywood in advance where the wires are located. Nails used for shear walls will penetrate wires drilled in the center of a stud.
  
• When new plywood is installed on the outside walls some architects call for 2 1/2" nails three to four inches apart. At he joint of two sheets of plywood there is Molly about an inch and a half to drill through the stud and not hit a nail. When you do hit a nail it sometimes times backs out of the wood a half an inch. Later a carpenter will come along and hammer it back in if you do not totally remove the nail and mark the spot with red chalk.
  
  
• Metal staples can crush romex wire and short the wires. It is in the interest of the careful electrician to check the operation of all wiring in a kitchen prior to closing the walls. A crushed wire will cause a circuit breaker to trip of a GFCI outlet receptacle to trip.
  
  
• When adding a GFIC to existing two wire power be aware that metal romex clamps and metal box clamps will in certain circumstances short the hot lead to the ground wire causing the ground in the GFCI to become electrified. Do not tighten metal clamps too tightly.
  
  
• Leave 4-6" slack in wiring so that you can later adjust up or down an outlet box. Nevertheless, staple the romex slightly loose within 8" of an outlet box. You can leave a loop above the top plate or under the bottom plate. Run the wire in a square pattern instead of tightly delivering them to each outlet book. Leave a foot of slack near recessed lights, house owners are always changing their minds about the placement of recessed lights.(More info)
  
• When working in kitchens around installed gas stoves, be aware that bumping some flexible gas lines will result in gas leakage. Ridged metal gas pipes can and do break where the threads end on the pipe. The metal crystallizes over time and the pipe just snaps off . This is particularly dangerous in basements where there is a gas water heater and you crawl over a pipe nearby, and break it. Although this is very rare it does occur.
  
• Installing recessed lights in ceilings that have insulation requires insulated lighting fixtures. California codes do not allow recessed lights to be boxed in with plywood. You cannot put the non-insulated housings up against the wood or ceiling of a joist bay. 2" clearance is required
  
• There are some kitchens in very old houses that still have gas pipes installed inside the light junction box for gas lighting. Before cutting the pipes off, be aware that some of these gas lines are still connected to the gas service.
  
• Do not install metal outlet or switch plates on receptacles that do not have a ground wired to the switch or duplex outlet. NEC 380-9
  
• When using 12-3 or 14-3 wire to deliver two circuit in one wire be sure to install a common-trip two-pole circuit breaker in the main or sub panel. 240 volts is present on the end of a multi conductor cable. Turning one leg of the 240 v off leaves the other leg energized. When a person is working on a disposal/dishwasher outlet under the sink they are in a confined area that could be hazardous to their health if one leg of the dishwasher/disposal circuit is still energized.
  
• Using 12-3 wiring can lead to appliance burn-outs. The neutral to wire must be firmly connected between the breaker box and the receptacles. A dishwasher on a 12-3 circuit will burnout when the disposal on the same wire is turned on when the white (neutral) wire is disconnected or poorly connected.
  
  
• Drilling floor or ceiling joists in the wrong place destroys their structural strength. If you have 12" ceiling joists then the holes you drill must run horizontally along the beam 6" from the top or bottom of the joist. Space the holes several inches apart horizontally. Do not drill holes larger than an inch without approval of a general contractor, architect, or engineer.
  
  

  You cannot drill into prefabricated Glu-Lam or Paralam beams or joists without following the drilling instructions that come with them. An engineer or architect can specify the drilling patterns in joists.

  
  
• If you are drilling a large number of holes horizontally in joists contact your local inspector for the location of the holes. Many inspectors prefer small holes be drilled horizontally in the outer two-thirds of the joist, each hole being separated horizontally by a few inches of distance. Three-quarters of an inch is a small hole. Drawing
  
  
• You cannot cut a notch on the edge of a joist. If you start with a 2 X 12" joist and you cut a 2" notch in it, it is no longer considered by engineers to be a 2 X 12. It is now considered to be a 2 X 10 joist. Never, ever, notch floor and ceiling joists.
  
  
• You cannot place an un insulated recessed light housings near wood. The instruction call out the distance, usually 2" from flammable material. You cannot fill around an insulated housing with insulation, nor can you in California build a box around the fixture to keep the insulation away.
  
  
• You cannot bury junction boxes with wires in them under plaster. Not only is this an electrical hazard it is annoying for electricians trying to trace an electrical problem in a house. Since they cannot find these boxes they usually will rewire the circuit at great expense to the owner. Many a home-owner has had to pay anywhere from five-hundred to fifteen-hundred dollars to have a new circuit installed because the old circuit connections came loose in the buried junction box.
  
  
• Note: leaving romex wire hanging from the ceiling at eye level can damage one's eye. It is best to bend a little loop at the end of the romex to keep the sharp edge of the wire from poking your eye when you get in a hurry or walk through the kitchen in the dark.
  
  
• Warning When removing tile from the walls of old kitchens be aware when hammering or prying on tile, that chard's of broken tile fly farther than you might expect, and they are extremely sharp. Wear safety glasses.
  
  
• Ladders are dangerous. You might not think they are. There are 500,000 accidents a year involving ladders, costing 11 billion dollars in medical costs. It is difficult enough to avoid accidents on good ladders without having to deal with a rickety one. If you are working with an 8' ladder and a hammer is laying on top it will of course fall. Sometimes open sheetrock knives are left on ladders. Be aware of looses shoes on extension ladders. As you climb down the ladder you easily can slip at the place where two parallel rungs side by side suddenly change to one rung. Angle drills will fall when you fall, and sometimes the drill bit will impale the person when they fall on top of it.
  
• When working under the sink be aware that if you get a shock because you left the power on you can hurt yourself because you are trapped in a confined space. At a minimum your arms will hit the cabinet in a most painful way. If the power to the receptacle under the sink is a 12-3 wire the circuit breaker must have a "common trip" handle to shut off both circuits at once.
  
• When drilling in tile remember that chard's of tile are sharper than metal or wood shavings and can hit a person in the eye well beyond arms length. It takes years of near misses for electricians to realize how dangerous drilling or chiseling tile is. When working with tile wear gloves and wear protective glasses.
  
• 
  

  Danger: If you are adding outlets in a kitchen using knob and tub wiring as a source of power be aware that while a GFCI makes a legal receptacle for two wire to three-wire conversions it does not prevent the very dangerous back feeding of power into the ground wire in the new romex wire you are using when a metal clamp short the hot to the ground when over tightening the clamp. Add a solid ground wire to the kitchen water pipes, both the hot and cold pipes together at the water heater and make sure there is a grounding wire from the main panel at the meter running to within 5" of where the water line enters the house.

  
  
• Placing outlet boxes in Firewall's: Do not forget these requirements.
  
• Volume 1 of the 2003 edition of The UL Fire Resistance Directory contains the information necessary to properly place outlet boxes in fire rated walls. Please note in fire rated wall 1. the outlet boxes must be rated for firewall's, 2. outlet boxes placed on the other side of a firewall must be at least 24" away (horizontally in any direction). Do not place boxes back to back in the same stud bay.
  
• Sheetrock Hazards Whether you are having sheetrock installed or installing itself be sure to map out where outlets and switches are. It is not uncommon for installers to cover an outlet or recessed light. Sometimes installers stuff paper in low voltage recessed lights to push the wires up into the can, but sometimes they push up the wires and the bulb which can ignite the paper.
  
• Design Hazards
  
• Before installing outlet boxes determine the height of the baseboards. In old home the baseboard is 10" so if your outlets are 12" on center you will have a design problem
• Before installing countertop outlet boxes determine the height of the countertop including the back splash. Leave at least 2" of height above the backsplash for proper conventional placement of outlets.
• Determine the width of the molding around the door and windows before installing switch and outlet boxes. Conventional designs place the edge of the outlet box 2-4" from the molding.
• Do not forget other types of wire for the kitchen such as telephone, network, cable TV, security and doorbell wiring.
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This web site is for use by competent people who have mechanical and electrical skills. Read and verify the subject matter here using other sources.

Copyright ©2005 dp
All rights reserved

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This web site is for use by competent people who have mechanical and electrical skills. Read and verify the subject matter here using other sources. National electric code reference numbers are given to you in an attempt to minimize any errors that may occur in the writing of these web pages.

Disclaimer

The author of these web pages takes absolutely no responsibility for errors in the text that might result in costly rewiring. Every attempt is made to be accurate. This information is free and frivolous running around blaming writers for every situation that goes wrong discourages the free flow of information to the community that badly needs perspective on issues such as electrical wiring. All electricians rely on the Nation Electric Code. Rely on the NEC code as the final word on what is to code and what is not.

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Copyright © 2003-2005 DP
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