Electrician Talk page 2

89 thoughts on “Electrician Talk page 2”

  1. Hi,
    If you step up 120vac @ 40amperes with a step up tranformer rated @5000watts to 240vac, will the amperage stay the same?

    • line or load, are you asking about? The line amperage or the load amperage? Define your wire size for each. What is your load side drawing or are you wanting a full load answer? This is to help prevent you problems and a important safety check.

      • I have a generator that is rated on the 120vac side @ 41.7 amps and the 240vac side @ 20amps and I was trying to figure out if using a step-up transformer would allow me to get more bang for my buck, no pun intended. I would be using 8awg copper.

        Thanks, Still learning.

  2. Yes, 60A is more than enough. The air compressor is a 5HP motor with a FLC of 27.5A (22A x 125%). Manuf. states the unit has a 44A LRA. I appreciate your help and thank you for your quick response.

  3. Hi. I would like to use a Siemens Disconnect 3 Phase as a 1 Phase double pole and was not sure which terminals to place the black and white(black) wires into or if it even matters. The disconnect is 60A /240V AC (V-) Max. / 250V DC Max, Type VB II and Type 1 – Indoors.

    Additional Inform:
    Black, White and Green, #6/2 wire, 2 wires 1 ground, 60A 2-Pole CB will be connected to sub-panel in basement, SO #6/2 same wire color to be connected to air compressor switch and to 60A disconnect.

    • Is your 60amp disconnect big enough? If so you are good.
      Just place your two line wires (incoming power) in the top on first two, left to right, and place your load wires (outgoing power) on bottom two, left to right and your done. Scratch the motor load comment, you are not using three phase so that does not matter.

  4. I am looking at feeding 100Amp RV pedestal that have the 50/30/20 receptacles in them. They will be for 50A rated park model units. How many pedestals can I feed off a 400amp main disconnect.

    • Is this a disconnect or a service panel with extra spaces? If it is a service panel with extra breaker spaces, how many spaces do you have open? Also, I believe the pedestals you have are only rated for 50amps. The reason you have different configurations is for the different types of camper receptacle styles. How much existing load do you have on this 400amp service?

      • The main service to the site is 2000Amps. We will be going off the 2000A to 400Amp Service Disconnects then using the TAP rule taping off the 400A to feed 100A disconnects to feed the service pedestals.

        • Let me know if this is not correct. You have a existing 2000amp service and you are installing several new 400amp disconnects on an outdoor free standing racking system with one tap box per rack going to your 100amp disconnects for each area? I would need to know many other details to help you. I cannot do a load calculation for you, if that is what you need for free. Because of many related code rules I would have to see your layout plans with specs. If you do not have plans or specs, you will have to draw out your plans with details and email them to me. If interested in paying for services, let me know. In other words, no way to do a quick answer as to how many pedestals you can have on each disconnect rack without many needed details.

  5. the zinsco panel was the original panel– a GE panel was added with a meter base– the electrician left the neutral wires in the original panel but spliced the hot wires to the GE panel and installed breakers– instead of running the neutral wires over with the hots they substituted a #6 thwn wire as the sole neutral and tied it back to the neutral bar in the zinsco panel as the connection for the neutral connection– so at this point all the breakers are in the GE panel and no breakers are left in the zinsco panel– its like a junction box as opposed to a subpanel

    • Ok, I see, it was done illegal. This is called a rat electrician job. If you want to make it legally correct, you will have to make your GE panel be the first panel the feeder wires are connected to from your meter base. And just take your old zensco panel and wires going to it out. There is no other way to correct this situation and it meet code. I still do not know how your grounding and grounded conductors are connected to the GE panel? How are is everything wired from your meter as far as grounding? Is it going to the old zensco panel too? Then to your GE panel? If you have everything running through your old panel, you will have to get it straight by a licensed electrician. It is too much to explain here. I can.t explain how to install a service correctly over the internet.

  6. In a panel changeout–the neutral conductors were left in the old zinsco panel and a #6 neutral was run to the new panel with all the hot conductors– the #6 is suppused to take the place of the other neutrals– don’t know about this sec 300.3b nec contradicts this I think– you have any experiance with this wiring method

    • Which one is your main panel coming from your meterbase? If the Zensco panel is your main panel, you need to connect the second panel as a sub-panel. The second panel must have 2-hots, 1-neutral and one ground. Your neutral must be isolated from the ground in the sub-panel.

  7. i have a junction box with a black & white from my panel,a black&white from my switch,and a black&white going to my light,they are all #14 THHN,obviously the the greens are spliced and tucked away,how do i complete this splice?

    • What are you powering and what is the voltage? I assume it is single phase American power?

  8. I have a new home and in my master bedroom my tv goes off when I turn my ceiling fan off? It doesn’t stay off it just turns off then comes right back on? It’s not just limited to the one switch on my fan but have noticed it happening with 2 other switches in my master bathroom? I think the lights and plugs are on the same circuit? Would that cause this to happen? Please help!

    • Normally in a new home the electrician will switch one or two plugs, maybe more in the master bedroom. The plugs themselves have a break off tab to separate the part that is switched and the normal power. This means ex: top half will be switched and bottom half will be normal power, or vise-verse. it sounds like the electrician forgot to break off the tabs on the outlets that are giving you problems. If you remove the plugs and look on the both sides of each plug, you will be able to see if the tabs are broke off. This means totally separate metal pieces, one metal piece on top half(hot and neutral) and one metal piece on bottom half(hot and neutral). What happening is when you throw the switch it is momentarily cutting off the power and back on again. With the tabs broken off, it should operate correctly.

  9. I just replaced a single-pole light switch with a single-pole dimmer. Now half the bathroom lights don’t work. Checked and reflipped breaker switches. Twice. Tested/reset CGI’s in bath and near by rooms. Still nothing. Weird. Any ideas? Could I have somehow blown a breaker switch, so the switch won’t even work?

    • Do you have florescent bulbs or incandescent? If you are using a incandescent dimmer with florescent bulbs it will not work. Look on the dimmer package, it should tell you.

  10. Recently bought a condo. Has garden lights that say 120v, 75watt bulbs (they are the high intensity typ bulb). There is power to the switch. Traced the wire which goes to a low voltage transformer and out into the yard to the lights. I’ve never seen full voltage lights used with a low voltage transformer. Is this possible? Safe?

    • No, and are they on and very dimm or not burning at all? what is the transformer voltage?

  11. I need a switch that will select between two sources of power. Source A is a battery pack, 8 12 volt batteries wired in series. Source B is a permanent magnet alternator capable of producing in excess of 96 volts. The switch needs to shut Source A off when Source B produces sufficient volts and will shut Source B off when it is not producing sufficient volts.

    I hope this understandable. Thanks.


    • Sorry but one or two switches will not do the job. What you need to think about is a control circuit. Components you may need: A AC voltage rated ice cube relay and a relay control circuit, a set of DC voltage rated contactors on both circuits with the contactor coils (AC voltage rated) wired into a low voltage AC relay control circuit controlling the contactors. The AC relay circuit needs its own power source and all the low voltage controlling components need to have the same voltage rating. Plus, if there is any way both power sources may be on at the same time, you need a designed control circuit specifically design for your situation.
      We can do that, but it is a paid service. I would need more info.

  12. I have some experience in electrical, thats why i asked about the fourth wire… do i put a ground rod at the panel? and will #2 wire do for the run? What size conduit will #2 wire fit into…1 1/2″?
    Thanks for responding so quick…

    • As far as the ground rod bonding point location, most of the time the ground rod bond gets bonded at the meter. This is determined by your local power supplier. In residential, different suppliers will require you to either bond your ground rod wire to the meter and some at the first point of disconnection. You need to ask your power supplier for that information. They sometimes have a written document explaining there preferred method. As far as the size you may need, 4-#2 THHN is legally allowed in 1 1/2 conduit.

  13. Im setting up a mobilehome, Im wanting to run a service wire to a panel (100 amps) close to the mobilehome from the main panel on the power pole. Gonna be a 115 ft run…underground. What size wire (aluminum) should I run, also do I run 3 wires plus ground or just 3 and ground the panel…

    • It sounds like you have spoke with maybe an electrician and you are considering the fourth wire. Most all local jurisdictions require mobile home services to add the fourth wire for grounding purposes. That is grounding not grounded. There is a difference between the two words in the field and in theory as far the electrical engineering perspective and a master electrician perspective. The fourth grounding wire should be bonded to the main grounding point on the premises. So yes the fourth wire should be used for grounding purposes only. Ofcourse the bonded neutral point is a different part of the equation. Make sure you know where to bond the neutral on both ends.

  14. i added a piece of wire for my well pump things worked fine for awhile the breaker broke yesterday i checked the connection and when i disconnected the ground wire it worked again i cleaned the wires they looked alittle corroded when i connected them again the breaker broke it works fine when the ground wires are’nt connected could it be bad down the line? it’s underground any help would be appreciated thanks

    • It sounds like you have either a motor about to burn up or a damaged line feeding it. If you are getting a breaker to trip when you connect the ground wire, then you have a shorted out ground to one of the hots or somewhere in the pump motor circuit to include the motor. Most likely it is the line feeding your motor. How deep in the ground is the circuit running back to the main panel? Has someone been digging around in your property? If so, they may have damaged it and it took a while for it to completely short out.

  15. ok THis is somewhat Split into Two Sections Left Channel and a Right Channel Left channel being set A (Black & White Wires)and Right Being Set B (Black & White Wires) Which will be the Feed
    Feed goes into an External Box in the Box there is now The Feed and Four Sets of Two Wires – I know i can take White wirtes and attach them to their respected channel’s Like Left b and Left f White can be combined Leaving white wire to match white feed same with both channel’s, now what i am needing is a switch of some sort to switch between the black wires to be able to turn on one set and leave other off and then hit the switch to switch them anything out there – i know a relay but i am looking for something light switch like.

  16. Secondary Panel was installed with no Ground. I placed a ground rod to create an isolated ground system, ( no ground bond strap at this time as all was clear) on field wiring. I verified that the exsisting circuits had no continuity to field wiring. All checked, and no ohm reading between Neutral or Ground wires, so it looked as thou previous wiring there was no tieing of these in field devices, ( neu to grd). The wiring in the panel previous had Neutrals and Grounds tied to the Neutral bus, as that was all that was there. At one time you could draw an arch and lights dimmed when bare wires touched panel before I grounded system. I Established the ground with ground bus bar and made it an isolated ground. All loads were checked for any amp load on the ground wires ) zero amps, and neutrals showed same as the hot wire for each circuit. After several weeks I was needing to wire in another piece of equipment and found one side of the neutral bus, several of them were chard and insulation burnt and even the bakelight back plane was disfigured. Temp check noted 110 to 115 degrees. The other side of neutral bus was fine, as well as breaker wiring. checked load and 4 amps and 6 amps on white wire that were the hot (temp) wise. Loads did not seem to be issue. There had been some lightning and storms in the area , but several days before. I cleaned up and reconnect white wires and took temp checks for 30 minute or so. No temp issues. I felt something from storms, such as surges or sags and damage was done. Several days have gone by and again the temp is up at 112 to 115 same place. I am at a loss for this. any Suggestions? Thanks Mark

    • First of all, if do you know where the isolation point should be for the neutral or ground, there would be no way to show you. It depends on the type of setup. It sounds like you are concerned about a voltage loss too. If you are not losing no more than 10 percent plus or minus things should be ok. If you are that worried about it call a licensed electrician. Thanks

  17. i have knob and tube wiring in my basement with several connections where the wirers are twisted together , soldered, and taped with black elec. tape. Is this legal or do these connections need to go in a juction box? If so this will be impossible as the connections are not close to a stud where a juction would be mounted. is there other options like insulated butt connecters, or whatever? I do not have an N.E.C. book

    • Knob and Tube wiring was used extensively through the 1950’s. Into the 1960’s 2-wire romex systems were becoming the common method. If this type of wiring system is touched, it voids any local electrical grandfather code rules that may apply. If you are not having problems with this knob and tube wiring system, i would just leave it along. But if you plan on replacing all of it, replace all of it, not just part of it. Knob and tube wiring does not follow the newer wiring system codes.

  18. i have a hot going to a switch. the hot is good according to my fluke tester. solid tone. from the switch i have a light wired to lamp in ceiling, the lamp is a ceramic lamp that is used in unfinished basements. when the switch is off the lamp does not test that it has power according to my fluke. when i cut the switch on there is power to the ceramic lamp and the lamp its self has power. but when i screw in a light bulb the light bulb does not glow. i used three different bulbs. i changed the ceramic lamp out light bulbs still do not work. thats what i know. as far as wiring the nuetrals are with nuetrals , hot with hot and a pigtail form hot to switch and black wire from light connected to switch. but light bulb wont work and the breaker does not kick. house five year old. help please. bulbs are good tested in another lamp devise.

  19. My mothers house is 45 years old. When she plugs in electric heaters, the cords get very hot and she is afraid to use them because of the threat of fire. Is there some type of plug she can use in the wall socket and then plug the cord to the heater into to help the problem. I’m sure the wiring is not up to today’s codes in her house. Thanks

  20. I have a 3 phase 240v delta panel with a high leg and would like to install a 3 phase 120/208v panel out of it. What type of transformer do i need to install?

    • Do you mean a 3P/120V/240V/delta wound with high-leg of 208V transformer? If that is what you have intended to say, then you must use a panel rated for the same voltage or higher. Just look at the sticker on the panel door to see if it meets your needs. if you have 208V rated panel then the rating is lower than 2 legs on the transformer voltage so you are not allowed to use this panel.

  21. I want to disconnect the power line going into a light switch and use it to create a new outlet to power a TV. The light switch powers a light in a closet that isn’t used. Is there any reason why this wouldn’t work?

    • As long as it is properly wired, I do not see any reason why it would not accommodate the Television.

  22. The lights/electrical stop working when the the lights were turned off this morning in the top floor of our house. One light had been flickering the past few days in the bathroom. We have tried to flip the breaker throughout the day. What/where should we check for a problem. Electricity in the remainder of the house is still working.

  23. thank you for your response!
    If i could ask your opinion once more, it would be appreciated!
    As an alternative to the above mentioned senerio. If i where to install a subpanel in the pump house that had only 1 split beaker ( breaker divided as follows: 15amp(single pull)/30amp (double pull)/15 amp (single pull)) would my current #10 stranded awg httn wire be suffiecent to carry both circut loads back to service panel? Or would i need to upgrade service wire to larger gauge to carry both loads?
    As of now i’ve invested in all the wire except the 2 additional #12 lines that i would need for the 20amp (outlet/light) ciruit. I was informed the best senario might be to place disconnects as close to service as possible, i.e – in pump house rather than service panel 180′ away.
    My intentions where to install a GFI outlet in pump house and pull a single leg off it to feed the light. Would the GFI suffice for safety reasons to protect that curcuit as power disconnect in the event a short shoud occur rather than having only the breaker 180′ away on the service panel? are both senarios ok? Thanks agian for your help!!!

    • Because of the number of NEC code rules you will need to follow, I would get some professional advice from a licensed electrician.

  24. I’m running new power to a well 180′ from service panel. using #10 thhn awg wire for 30 amp service. I also would like to have an additional GFI outlet and 1 light inside the new pump house. sense i’m already pulling (4) #10 wires thru conduit (hot/hot/neutral/ground)for the well pump, can i pull 1 addional wire thru conduit (hot) #12 thhn for a total of (5) wires and use the (neutral/ground) of the 30 amp service for the neutral/ground for the additional outlet/light circuit. the outlet & light circuit will have its own 20 amp breaker in the service panel?

    • no, since you already are sharing the neutral for the well pump circuits (2-total), you need to have another neutral to go with the additional hot to be up to code. Using the same ground wire is fine.

  25. 9 times 60 is 540 watt plus 300 equals 840 watts. Your fan remote control module located in the fan housing needs to be looked at to see if the total wattage it is capable of handling IS 840 watts OR GREATER.

  26. Message:
    I have a a light that has 9-60 watt bulbs it is connected thru a fan
    remote control that is rated at 300 watts Is this a problem?

  27. Message:
    I have a rotary dimmer switch that stopped working after many years. I
    replaced it and it stopped working after about a week. I replaced it
    with another rotary dimmer and it stopped working after about an hour.
    A regular toggle switch seems to work fine. What could be the problem?

  28. My husband and I heard a pop behind the headboard and then all the electricity in the bedroom went out. We pulled the bed away from the wall and the outlet was warm. While the circuit breaker was off, I removed the outlet plate and outlet. It was charred inside. The outlet was black where one of the black wires should be connected and the black wire was scorched. We have not turned the electric back on. How do I determine what the problem is? Outlet? Wiring?

    please call an electrician to look at this!

  29. Message:
    I’m installing a new GE timer to control 3 outside lights. The old
    timer had a black wire connected to a black wire in the wall box and a
    white wire connected to two wall box wires, a red and a blue wire
    braided together. The red timer wire had a wire nut and not used. The
    same with the green ground wire. I tried to install the new GE timer
    the same way as the old one. But it doesn’t work. The GE timer calls
    for the red timer wire to be connected to a second black power wire
    from the wall box. But there is no second black wire. Only a red and
    blue wire along with the one black power wire. So my question is, what
    is the hookup? Do I connect red to red or red to blue? Do I connect
    white to red or white to blue? Do I connect red and white to braided
    red and blue?
    Thank you.

  30. Message:
    Hi I have a question, I need a little assistance answering, if someone
    could help me out it would be greatly appreciated…..

    A motor has a full-load current rating of 74.8 amperes. What is the
    minimum allowable ampacity of the branch-circuit conductors?

    if you are only connecting the motor to the branch circuit, the wire size can be #4 thhn copper, and you will need a starter and overloads sized to your motor at the nameplate.

  31. Message:
    can i splice the wires from my ceiling fan to add an outlet in the
    ceiling for a projector? If so, is there a diagram to show me how?

    Yes, but your neutral and line hot needs to be in your ceiling fan box if you do not want to switch the new plug. If you do not mind the plug being switched, just wire nut onto your 2 ceiling fan wires to connect to your new plug.

  32. Message:
    i have a 3 phase panel only 2 hots and ground from a to b i have 240v
    from a to ground i have 240v and from b to n i have 240v no 110v

    sounds like you have a bad transformer.

  33. Message:
    I have a 200 amp service in my house. 120 volt single phase. I have a
    100 amp panel in my shop ran off a generator. I want to go from the
    house panel to the shop panel. It is about 325 feet of run. Can I run
    2/o Al without losing to much? Shop has air compressor (15 amp) lights
    and occasional power tool running but thats it.

    It should be ok. you will have a voltage drop of 3-5% per one hundred feet.

  34. Message:
    can a 12VDC LED strip light be connected to a 12VAC transformer using
    a rectifier. if so, would it be dimmable on the primary side of the

    if not, why?

    I never heard of 12vac, maybe 120vac is what you meant. A rectifier can change your voltage type AC to DC, but without properly sizing everything you may burn a few up. Why not just use a 120v step down transformer to 12vdc?

  35. Message:
    with 3 wire 4/0 direct burial aluminum wire it says it is good for 200
    amps.Is each hot leg good for 200 amps or is that the total for both
    hot legs?I am trying to determine what sizes of wire i need to put in
    certain meter cans etc 100 amp 200 amp etc…

    each hot leg is good for 200amps

  36. Message:
    I have wires coming from the wall red,black, white, cooper the water
    heater has red and black what wires go where. Thanks

    If the existing wire is properly connected to a 220v breaker, then use the 2 hots (most likely red and black, but better use meter)

  37. Message:
    Is it ok to use a 60 amp breaker at the panel and run number 6 wire
    from that breaker to a 50 amp breaker in a subpanel and then to a hot
    tub? Just asking because we are hooking up our hot tub and have the 60
    amp breaker left over from something previous. Rather than spend $100
    on a new 50 amp breaker for the panel was hoping to be able to use the
    60 amp. As long as it is bigger and not smaller then it is ok, isn’t
    it? Greatly appreciate any help you can give. Thanks.

    sounds like it will be ok.

  38. Message:

    I have a set of 4 strip lights in a small office which keep going off
    for no obvious reason. Only 2 have starters in so 2 stay dormant. All
    connections are sound and I’ve tried swapping the starters around to
    no avail. There’s no scorch marks or signs of overheating. Any

    change light bulbs to the correct sizes. read ballast tag to get bulb info.

  39. Message:
    i recently purchased a home. attached to the bottom of the outdoor
    service panel is a triangle shaped device with wires going to the main
    breaker and no where else. can someone tell me what this is.

    sounds like a surge arrester.

  40. Message:
    kitchen light turn on, only if i turn on the range knob, if i turn off
    the knob the kitchen turn off as well.

    sounds like you have a couple of bad switches and a wiring problem. you need to call a licensed electrician.

  41. Message:
    Can I use a Square D QO type panel and breakers for a European
    230/400V 50hz system,

    As long as you do not go over the listed rating on the breaker and panel. It will be stamped on the components.

  42. Message:
    On a remodel, a dedicated kitchen circuit will have 4 receptacles
    (counter top). The first one downstream from the panel is GFCI, the
    next 2 are regular rec off the load side of the GFCI, and the last is
    an outdoor convenience rec also GFCI. Is this correct? The homeowner
    wants all GFCI. Also, do they have to be 24″ apart? Thanks, richard

    They are connected correctly. But you cannot move one outside. They all have to be dedicated to the kitchen counters. 24 inches is good.

  43. Message:
    My florescent light stopped working, there was no flickering. I
    figured the ballast went so I changed out the fixture with a standard
    light fixture. All the wiring is correct. The reading on my multimeter
    is 0 Volts with the breaker on or off. Could the breaker be bad even
    though it never tripped? The breaker is 16 yrs old

    check your light switch. There is no way you would have power if in off position if breaker is good. Change breaker too.

  44. Message:
    current generator under repair, i’m hooking a portable generator up
    and i have taken leads to generator and hooked up to portable
    generator. I used nuckles to splice together temp. and taped up very
    good. What does nec code say about a temp hook up?

    not enough info.

  45. Message:
    What exactly is a Street L?

    A conduit body used for quick corners. The inside can be accessed through cover plate. It is a pulling point for wire.

  46. Message:
    in an three phase line using 15 hp induction motor without no load the
    capacitor connected in the line taken large amount of current in
    no load it takes more than 5 ampere current per each line give me the

    Do you have the wire sized properly? no answer can be provided without more information.

  47. Message:
    Hi I just installed 4 fence post lights. They are hard wired from a 20
    amp fuse. One of the light bulbs keeps blowing out.Do I have a short

    most likely.

  48. Message:
    I recently bought a computer and UPS to protect the computer and
    peripherals from surges and allow to safely turn off the computer when
    there is a power outage. The UPS (APC brand) has a softare whic
    monitors the AC voltage turns off the computer if the voltage is low
    or higher than a range of voltage (92 – 139 V). In some evenings, the
    voltage where the APC is connected is more than 139 V and
    consequently, the computer is turned. At the same time, in another
    room, the light flickered.
    What could have caused the overvoltage?

    It most likely has a voltage setting. Try that if it has one. 130v would be a good voltage setting.

  49. Message:
    what is a transformer soak pit/transformer oil soak pit?

    This would be more an industrial question. A very high voltage transformer vault, underground transformer that holds non-conductive cooling oil.

  50. Message:
    Is it legal to mount a lighting panel above its transformer? Can i
    mount a 150A panel directly above a 35 kva transformer? All i see in
    the NEC is rules on working space and nothing about mounting. Pleas

    That working space rule follows invisible plane to floor. You must have clear working space approx six foot high to floor to be in compliance. This is a very common question. Thanks

    So can I mount a panel above a transformer?

    No, you have to leave the working clearance as stated.

  51. Message:
    I replaced two flourescent fittings in my kitchen a year ago 9 months
    later one of them stopped working so I got it replaced now that
    fitting has stopped working 3 weeks after I got it replaced. Do you
    have any suggestions why this is happening.

    without being there and taking a closer look, it would not be possible to answer.

  52. Message:
    A house has voltage in 230v, 6*100w lights, 2*2kw hobs and 1*9.8kw
    shower. 1) what is the total kw? 2) what is the total amp? 3) what
    size cable will be used for each circuit. (twin pvc/pvc). 4) what is
    the cpc size of the hob supply? 5) what is the current use of each
    circuit? 6) are there any allowances for deversity on the shower


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