Home – Business wiring system help before you hire.

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108 thoughts on “Home – Business wiring system help before you hire.”

  1. Hello ~ My husband had basic teaching in tech school. We remodeled upstairs bathroom. The situation with the outlets was there is a light switch by door that turns on light and the second switch turns on ceiling fan. Then there’s two outlet boxes on wall. The one to the left of the mirror near the shower (strangely) had no outlet – no plate, just the wires capped off and all open. The second outlet to the right of the mirror did have the gfci outlet installed but only worked if the ceiling light switch was turned on. Husband was always disturbed with this. Now that we redid bathroom, he simply replaced the gfci outlet with a new one. Only this time he grounded the wires – because they originally weren’t! Then he went to the other box and put in another gfci outlet. He replaced the light switches as well. Then when he turned the fuse back on, the outlet to the right of the mirror worked but not the one to the left. Turns out it’s on a separate fuse. But the funny thing was that even though we had the fuse to the right outlet off which the light switch sends power to when on, the moment he put the black wires on the top of the new (left) outlet, the ceiling light came on! Then after everything was together and both fuses on, things were whacko. The ceiling light wouldn’t turn off and the outlet was blinking red (or steadily red, I forget.) It seemed hooking up the left outlet made everything crazy so he undid the wiring in the left one. Well, we thought all was back to normal and as far as the light and the outlet working only when light switch was on, that was indeed the case. But then when we were downstairs and turned the switches on at the foot of the steps for the downstairs ceiling lights, they wouldn’t come on – UNLESS THE UPSTAIRS BATHROOM LIGHT was turned on. And we never had that issue before. Any ideas? He wired everything as it was plus grounding the outlets. Much appreciated.

    • It sounds like a couple circuits in that area could be sharing a neutral(white) along with those circuits(hots) trying to connect to one another. This does not mean its a huge wiring problem YET, it just means someone has possibly been trying to get creative without the electrical experience or with the understanding that it could be very dangerous to anyone living in that house if it causes a fire.

      From my experience with sparking like you are having and its residential service call, I immediately think its unqualified person that created the issues. When breakers are energized for troubleshooting purposes and multiple electrical devices or fixtures begin throwing sparks in one general area of the house, it usually means its going to be a very long night and long next day looking for the problems and correcting them along with helping the owner feel that things are getting better. And that is if its easy job to get corrected.

      In my experience 9 times out of 10 these types of service calls ends up more dangerous than it would have been prior to any attempted fixes. “Emotional hiring” like these happen a lot and are common when the cost for a licensed electrician is found. Unfortunately for you, your problem needs a licensed electrician to put his eyes on the problem. That is unless you are close to Birmingham Alabama.

      I recommend you make that call and get it taken care of asap!

  2. I need to run a 220 circuit for a Lincoln 210 MP welder. The welder is rated for 200 amps 24 volts 25% duty cycle. On the plate for the unit it shows U1 230V 1max 27A 1eff 14.7A. The machine is single phase.

    The plug that comes with the welder appears configured for a 5-50R receptacle.

    The distance from the panel to the outlet is approximately 50ft.

    I need to know the following:
    1) What size breaker should I use.
    2) What wire size I should use.
    3) What receptacle amperage should I use.

    I have tried contacting the manufacturer but they have not responded.

    Please advise.
    Thank you.

  3. We have our own transformer on a pole for our property and about 11 years ago on Thanksgiving it blew and the power company came out and replaced it. From that point on our electric bill DOUBLED and I could NOT get the power company to help!! Well just recently, they revamped a lot of the poles in the neighborhood as well as switching out our transformer and the new one they put in is MUCH smaller than the one they replaced on Thanksgiving 11 years ago. Oddly enough, our bill has dropped at least $200.00!!!! My question is could they have not had the right size when they originally replaced it and put in what they had which made our electric bill shoot up?

    • Bad windings in a transformer can raise your power bill. Sometimes bill surges can be helped by replacing your transformer, meter-base and repairing bad spices between your meter-base and your transformer. One way to check your thinking is to check to see if any other lines are running from any other house and connecting to your transformer. If any exist go ask if they are having same problems.

      • yes, one switch controls all of the lights, and I want a second switch to control only the 3rd light, do I just power this light separately and wire the switch before the light?

        • Yes, disconnect the existing switch leg wires(both white and black, ground or green can be left alone) from your 3rd light, wire nut them together and let them run to next light. Because most likely they are wired from one light to another. Then take your new hot(black) and neutral(white) and green to your 3rd light and connect hot and neutral to fixture, green is already connected. If you plan to have new switch box and do not know how to cut-in new box let me know. You can either cut-in next to your existing switch and use that circuit or use another, that is up to you.

  4. I’m replacing my service on my home. It is a small house with tin roofing. Because of the house construction and the placement of the transformer I’ll have to put an exterior 200amp main with meter on the side of the house. I’ll need to run my service head through the eve of the house. As I read NEC I think I need to be at least 3′ above the metal roof and at least 12′ from the ground. Is this correct and can I use sch. 80 pvc or does this need to be metal conduit?

    • The code is not the final authority when it comes to residential meter riser builds. The local power company has the final say on the LOCATION of the riser because it is coming off there poles to your house. The NEC code and power company together tell you HOW to build it. But it does need to be rigid conduit in most areas.

  5. Garage Door Issue. I’ve narrowed the problem down to wiring between sensors and opener box. I’ve check the sensors, they are good. A blinking of one light says it’s the wiring between sensors and opener box. But I’ve check the wiring and only noticed one area where the wire is not totally insulated. There is no contact of wire to wire, just one wire that I can see the copper (about an inch worth and the other wire is totally insulated. My question is basic. Can a wire that is not covered but not contacting anything cause the garage door not to work? There is no cuts, or anything else that I can see. And if that is the problem, will just wrapping black electrical tape around the wire fix the problem if that is the problem. The wire that is expose is in the attic, probably happened because of rubbing over a rafter. It is not broken or cut (just exposed). I’m thinking that is not the problem, although it needs fixed.

  6. I am interested to know the codes regarding; can you operate a 120v air conditioner on a extension cord (approx. 8 foot long and 12/3 rating I think) in a motel/hotel industry. I have been in maintenance for over 20 years and know basic codes and have a code check book but it just hits base with the basics and more residential, it states max cord length 120v=10ft 240v=6ft. But because we rent rooms and the liability that goes behind that and also in this particular setting the building was wired with 2 rooms outlets to a 15 amp breaker at the load center (which pops sometimes if both rooms are using the hairdryers at the same time) at this property which I have been filling in for due to the properties maintenance walked off the job the property was set up for 240v heat baseboard style and 240v air conditioners plugged into the heater baseboard but he miss ordered the air conditioners and ordered 120v and just bought extension cords and ran it to the nearest outlet. I apologize for the long winded request but there must be a code from doing this in the commercial maybe and not residential end of it? any insight would be great thank you

    • That would be considered a permanent appliance so no cords would be allowed. Cords can only be used for temporary purposes. This is why so many fires happen when extension cords are used. This is going to cause him a lot of problems if he insist to use cords. I would tell the owner he made a big mistake ordering 110v A.C.’s. And he is looking at constant problems if he doesn’t reorder the 240v A.C.’s. He may be looking at the local codes enforcement giving him a visit. I am sure he gets yearly visits from the local fire code official to check his fire alarm and exits. If he is determined to use the 110v A.C.’s installing new dedicated 20a/110v outlet at every A.C. location would be only way to solve.

  7. A few months ago 2 of our lights kept burning through light bulbs….we kept replacing them….then our lights started to flicker causing our tv to turn off and come back on. A breaker was not tripped however, we replaced a lighting breaker anyways and we were good to go for a few weeks. Now our electricity is flickering again…no breakers tripped again…we replaced the other breaker directly related to the rooms that we were having the issue in and electricity is still surging off and on at nighttime. We have a clamp meter however, don’t understand how to tell if one of the other breakers are bad or not… does this sounds like a breaker problem or something else? txs

    • It sounds like you may have:
      1.) Bad Panel
      2.) Loose connection
      There could be a couple other problems but it will take a licensed electrician to visually inspect to make any conclusions. This type of problem most likely is not a small problem and just can’t be properly diagnosed without in person visit. Most likely this will require changing out some major parts. Don’t play around or wait to get these type of problems repaired, it could be a fire risk.

  8. i have an exterior flood light fixture recently removed by contractor residing my house. The light was working but was recommended the it be replaced as there was water in the base of the unit. new fixture installed, the light is on when the wall switch is on the off position, goes off whenb the flip the switch which normally would be the on position and trips the circiut. Any ideas whats going on? even removed the fixture and just the flip of the wall switch trips the circiut. please help

    • It sounds like the electrician was in a rush and made a mistake by wiring a short. I would call him back to take care of it. I cant help you at this point because he has to finish his job. If you have anymore questions feel free to stop by anytime and ask.

  9. I dropped a necklace chain and it fell on the prongs of a plug that was plugged in to a power strip. What a freak accident that it would fall and land exactly between the plug and the outlet. It popped and smoked and the power went out in the rooms on the circuit. It didn’t trip the circuit but we replaced the circuit anyway and also the plug that the strip was plugged in to. Nothing is working. What else should we do?

  10. My home has 200 Amp service coming in to it I have 2 breaker panels in the home one with a 200 AMP main and one with a 60 AMP main both are connected at the meter. Is this legal?

  11. Hello yes if i pulled the pull cord switch it would turn the light on and off and also if i switched the switch on the wall that would also turn the light on and of but since i removed the pull cord switch the wall switch will not turn the light on or off hope this helps


  12. Hi could you please help in my bedroom i have got a wall switch and a pull cord switch but the bedroom is not very big so i removed the pull cord switch and tied the wires up with a block connector and wrapped in electrical tape but now when i use the switch on the wall the light does not work your help would be much appreciated

    • Did your pull chain and switch operate the light before? If you switched the switch or the pull chain up or down, would they turn the light on and off separately?

  13. I need to know I am replacing my old air condioner it works off a 230 voit tandem plug type hooked into a double pole 20 amp circut breaker
    all the new one I am looking at are 230 voit 15 amps systems will I be able to use them with the current 20 Amp that I have

  14. I converted a can light in a ceiling with an adapter that screws into the bulb socket. then plugged in a two prong adapter for two puck lights to be install in a bookcase. this will be behind the crown molding above the cabinet. Just wanting some feedback?

    • We don’t quote the NEC codebook because everything here is free but, I can tell you the NEC code book would not allow this situation in new home wiring or any electrical remodels, both commercial or residential.
      As far as the reasons why this should not be done is mainly because of fire code reasons. It would be difficult to explain to you how to how to install this fixture with me not being there, but because of the additional lamp holders or bulbs you have added additional current & heat load to the factory design single bulb light fixture, the additional wattage & heat that is created along with overloading the factory wiring in the existing light fixture is a fire hazard and because you have manipulated the factory design. It other words it is too close to furniture. If you kept it as a recessed single bulb and did not install the two bulb extension, it may have been ok.
      You need to not install any light fixture within 3 foot of any combustible material (Ex:wood, cardboard, drywall, paint,) without the proper UL listed insulating material for that type of bulb. So I recommend using the correct fixture for that installation area or just keep the recessed fixture the way it was in the first place. Try low voltage LED strip lights or LED rope lighting. But you will still have to make sure your connection point is done properly.

    • Yes, you can control any contactor by any kind of switch. But you need to make sure the switch is rated for the situation. Electrically held contactor is just a common name for a contactor. It does not have to be an electrically held but if you have a very simple electrical control circuit then it will most likely be electrically held. It does not have to be electrically held. It could be a pressure switch or a latch relay of some kind.

  15. i decided to replace my breakers as they were old and found that one had two wires in it. i seperated them and when i installed the breakers one threw sparks and popped the breaker next to it. unhooked one and tested the other wire hanging and it was hot without being hooked a breaker in the box. what could this be and why was it ok when it was hooked to the other wire in the same breaker?

    • Yes, it sounds like someone else did some electrical remodeling. It was the same circuit number connected to the same phase when it was under the same screw termination point. When you are on same phase it will not arc like it did when you moved it to another breaker. When you moved the wire to another breaker it put the extra hot wire on a different phase which will trip the breaker. This happens more than people realize and is one of the most dangerous things that inexperienced people do trying to play Mr. Electrician. What this person did was they opened an electrical box somewhere else in the house and incorrectly connected wires. This caused that extra hot wire to feed back to the panel. This is called back feeding. Unfortunately they were very wrong and instead of correcting the problem they caused, they went to the panel and moved some wires around until they got it to where the breaker would not trip. This is a big mistake and can get someone hurt. Just leave the wire off the breaker and tape it up. If everything is working just leave it alone. When you get the money and time call a professional electrician and he will be able to get it straight. Thanks

  16. My son’s entire bedroom and two outlets plus the wall switch in my bedroom is on the same circuit breaker. Yesterday all these outlets went dead. I have replaced every single outlet and both wall switches today. I have checked where wires are capped to make sure they were ok also, and after replacing everything and turning the circuit breaker back on I was able to test with my voltage detector that all outlets were now getting juice ( where before not all were) but when I plug in anything it is still not working and the fan/light in my son’s room still not working…Please help…Thanks so very much.

    Alan B.

  17. I wonder if you could help me. Problem regards electric door opener/strike.
    The electric strike (door opener) obviously is on the door frame attached to the wall and then there’s the door with its latch plate and ‘tongue’ going in and out.
    The problem is this, if the door is opened (hence latch tongue not in contact with electric strike) or if the door is closed but the latch tongue is not out, is still within its compartment/latch (hence latch tongue is yet again not in contact with electric strike) then if one pushes the button to create a connection to open the door we can indeed hear the sound of it doing its job and one can feel the vibration. However, the minute the door is actually closed with the tongue within the door frame electrical latch then nothing happens, no sounds, no more current. How could this be? What is going wrong? and therefore what would need to be checked/fixed.
    Both the electric door latch and the ringer upstairs have only 2 wires
    thank you

  18. Haha thanks for the response. The job was in Tampa, Fl. When the second inspector showed up the following day, his first words were, ” I was looking over the notes from yesterday and I have no idea what this guy is talking about.” haha

  19. I am currently working on a commercial jobsite, remodeling a Beef o Brady’s. We left service loops on each of the 2×4 Lay-in Florescents that were installed. The loops being approximately 3, 12inch coils for a total length of 36 inches. Upon inspection the inspector says that you are NOT allowed to coil MC like that because you will create a transformer and burnt up the MC. Myself nor my foreman have ever heard of such a thing and we were wondering if this is true. Thank you for your time! By the way this is a 120volt circuit.

    • Where are you located? I will make sure I don’t do a job there..HaHa
      Just the opposite for me, I have inspectors and engineers have us make 6ft loops in case the fixtures ever get moved. That inspector don’t know what he is talking about in my opinion.

  20. There are no contactors for the lights, only special lighting panels with banks of relays controled by the computer. The low voltage switches tied to the system can be programed to turn all or some of the lights on/off. These panels are between the circuit breakers and the lights. I dont think the has anything to do with 3-pole breaker issue because the 120V branch circuits which are not part of the energy management system are all on 3-pole breakers as well. I was wondering if this was done since all the home runs are in four conductor MC cable and the three circuits tied together thus share a nuetral. If you can’t figure out an answer based on what I’ve told you to this point I’ll drop it here and try to get an answer from the local code body since this may be a local code ( there’s nothing in the NEC that I know of).

    • I don’t think that sharing a neutral should be a reason to use a 3-pole breaker. So the branch circuit going through this 3-pole breaker go straight to the light fixtures? They would have to go thru the contactors in the energy manage system to function first then from there to the fixtures. I don’t think there is a need for this if no other special devices are using this same 3-pole branch circuit..

  21. There are relay panels between the breakers and the lights. Both the buildings are on a programable, computer controled, energy management system that uses low voltage controls of those relays to turn lights on and off. All the room lights are turned on/off by low voltage control switches tied into the system or by motion sensors. This would however not explain why all the 120V recpt circuits are all on 3-pole breakers as well. We have had a few instances in which an appliance plugged into a recpt tripped the breaker controling that circuit that resulted in the other two circuits tied with the first being tripped as well . As I said before ALL individual branch circuits were tied together in this way .

    • because I am not looking at the building system, I am limited on what I can diagnose. But you may need to trace out your neutrals to find out why they may have needed the 3-pole breakers. I have seen a new energy management system that had to have an extra neutral for dimming purposes. That system only dimmed half the high bays themselves (in other words every high bay had power at the same time but this one wire adjusted the light level in the building by dimming half of the each high bay. This caused us to have to use that extra wire all the way around the building and when you cut of one breaker it was tied to a contactor that opened all circuits at the energy management system.

      Are you sure the branch circuits are feed straight to the contactors? This includes every wire, hots,neutrals, grounds,etc

      You situation sounds similar to something I discovered.A few years ago.

      The engineer would not have made a mistake like that surely? Well I have seen them guys make plenty of mistakes come to think about it. But anyway,

  22. I could do that except this is a brand new building and all the branch circuit outlets including 277V lighting were done this way by the contractor. I would have to assume the engineer spected it that way, I was just trying to figure out why because it makes no sense to me or anyone else in the maintenance dept. Could it be because all the circuts are in MC cable sharing a nuetral?

    • I am back, do you know if there are contactors between the breaker and the lights? If not, Do you know if these lights have an emergency backup ballast too? If they do have an emergency ballast, that ballast may be sharing a neutral but on a different circuit and if the normal power is cut off it may affect the ballast on the emergency circuit. This could be a method used to prevent a problem if the normal power circuit breaker was accidently cut off.

  23. In all the panels individual 20 amp branch cicuits feeding recpt’s in offices and other rooms the circuits are landed on three pole breakers instead of indvidual single pole breakers. This results in three circuits tripping instead of just the one .


  24. In new facilities all our panels have some individual branch circuits tied together by three pole breakers causing common trip between circuits un-related to each other (offices and equipment). All these circuits are in MC cable. I can find no reason for this in the NEC.Why would this be done?

  25. I have 3 electrical wires pigtailed together and everything works but when i turn the bedroom light off it flips breaker off. That is the only switch that flips the breaker. What do I need to do?

    • You have a short. A short of this kind should be looked at by a Licensed Master electrician. Be very careful and leave this switch off until it has been examined.

    • Delta wound Transformer – Plant industrial uses (Motor loads) uses high leg for high current motor applications
      Y wound Transformer- Malls, mostly public buildings (lighting loads) no high leg needed for low current lighter loads

  26. I have an RV wiring question. We recently bought a resort property and they have 4 existing rv sites that are wired with #8 UF in one run that supplies 20 amp service to each site. We are going to provide 30 amp service to those sites. I wanted to know which is the proper way to wire this as my partner and I are having a bit of a difference in opinion. He wants to run two 30 amp sites off one #8 wire to a 50 amp breaker in the panel. I however think we need to run seperate #8 wire runs to each site and all be on their own 30 amp breaker in the sub-panel. My worry is if two rv’s run their a/c and nuke a burger it will opo the breaker and they will both be out of power. I just want to make sure we are not going to ruin ourselves and our reputation by having the breakers go every 30 minutes because we are under wired. Please help.

    • You are right, who would want to live with that worry. Life is too short. Yes add the 30amp circuits with a sub-panel. Make sure you use 4-wire system out to each RV pads. You will have a 2-hots,1-nuetral and 1-ground. Run any data lines in same ditch but in different conduit no less than 3-6 inches apart.

  27. I am installing 4 Metal Halide light fixtures at 1500 W each at 240 V on a pole. Each fixture pulls about 7 amps. What type wire do I need to run for this amount of lighting? 10 guage or 12 guage?

  28. Hello,

    I was hoping you can give me some assistance wiring smoke / carbon monoxide / heat detectors in my home.

    I have read up on the smoke and it seems easy enough: hot, neutral, and interconnect. My understanding is if one smoke is triggered it sends a signal through the interconnect to the other sensors in different areas of the house.

    My question: can I hook up carbon monoxide sensors in series with the smoke detectors. Same question for the heat detectors. Will the interconnect work with different sensors?

    Thanks for your help.

  29. just bought a light fixture and the 3 wires on the fixture are not identified! through investigation if figured out which is the ground but how do i know which wire hooks to the hot and which wire hooks up to the neutral?

  30. had power running from panel to 1 outlet everything was fine decided to add a light put junction box in power to outlet never changed added light switch everything was fine use one of those amish heaters ran fine for days not all the time light and switch still work fine smelled like something burning the other day unplugged the heater for a day never thought any more of it plugged vacum in to use it no power in outlet checked wire with my beeper thing beeped as it was hot somthing to worry about or just a bad receptical

  31. I am installing a fan w/light kit. The fan has a blue wire (for light kit) a white wire and a black wire. The wire coming out of my ceiling box is white, black and red. Do I hook up the white wire to white, black to black and blue to red? I also have a ground which I assume goes to the ground from the fan?
    Please advise.
    Thank You,

    • The standard is what you have quoted as far as colors (white to white, black to black, red to blue). Just make sure, if you have a volt meter check the black for continuous hot (directly from breaker) and the red for a switched hot (by switching your switch on and off while you have the meter connected). remember, First just make sure you turn off your breaker. good luck

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