Wires too short to reach new load center.

Discussion in 'Electrical Forum discussion & Blog' started by Mindz i, Dec 17, 2010.

  1. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    I live in a mobile home and have a Zinco load center that's going on the fritz. It's currently 100 amps. I figure I might as well put in a 200 amp box since our house is 100, our shed is 50 and our a.c. is 50. The new box I'm looking at is 28.7 in tall. This will put it too close to the ground since our old box is only 13 in tall and the bottom is 18 in from the ground (pictures below) and NEC 550.32(F) requires that the bottom of the load center be 24 inches from the ground. I'll have to mount it on the backside of the pedestal opposite the meter (example below).

    Currently, the load center powers a lug box in the house, lug box in the shed and an A.C. The shed has a washer, dryer, some outlets and lights. The lug center in the house has 2 awg aluminum wire running from it to the load center. None of the conductors will reach to the new load center. I really, want to avoid running new conductors for everything. It would get really expensive.

    So, my questions are, can I extend the conductors by splicing? And which is best for a 2 awg conductor, splice bolts or a butt splice kit? Can I gut the current load center and use it as a junction box? If so, what kind of modifications would I have to make to the old load center to make it code compliant?

    Current load center. (basicly a 100 amp lug box) It was installed in 1983.
    [​IMG]
    [​IMG]

    Lug in house.
    [​IMG]

    Example of what neighboring houses did when upgraded. Different owners now.
    [​IMG]
  2. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    So from connector to connector you need to add (29 + 24) - (13 + 18) = 22" of #2 aluminum?
    Last edited: Dec 17, 2010
  3. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
  4. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
    IMO upgrading to a 200 amp service would be a waste of money, especially for a manufactured home.

    Adding up the breakers like you did is not the proper way to size a service. A demand load calculation is the proper method.

    I have seen houses over 2k square foot that only needed a 30 amp 240 volt circuit for the A/C.
  5. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
  6. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    The home has three 2awg aluminum wire going into the current load center. Two of them connect into the top of the hot bus bar and one into the neutral bus bar. A forth aluminum conductor, which is the ground or common, goes into the neutral bus bar from the house, as well. I'm not certain yet, what gauge it is. The bottom of the new load center will be 5 inches higher than the current one. Add in the fact that the new box is twice as tall and the main breaker is much higher within the new box, I will need about 24 more inches of 2awg wire added to each wire to reach the new breakers. Plus, around two more feet for the common. And that's just for the home.

    The wires coming from the shed and are smaller. They are 6awg conductors. There are 4 of them. I would have to add about 24 inches to all four of them. And the wires from the A.C. are 6awg. There are 3 of them. Again, I would have to add about 24 inches to each of them.

    So, my question is, can I splice them to extend them? Or am I required to run new conductors? And, which method is best? Butt splice kit or splice bolts. Also, can I gut (take out the bus bar and breakers) the current load center and use it as a junction box?
  7. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    24" of #2 alum is ~0.5 milliohms of resistance. If you turn on enough appliances in your house to pull 50 A then the voltage drop across the wire + connectors should be less than about 25 millivolts if your finished connections of whatever type have integrity.
    A DVM should be able to confirm this.
  8. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    The A.C. does state a 30 amp minimum. But a 50 amp maximum. We were going with 50 amps to play it on the safe side. Currently, we have a 40 amp breaker for the A.C. Most of the homes around here are upgrading to 200 amps. The Chief Electrical Inspector, if I understood him correctly, suggests upgrading to 200 amps.
  9. Thatguy

    Thatguy Homeowner

    Messages:
    1,459
    Location:
    MD
    You can use your elec. meter and a clock as an ammeter. The formula is about 1/3 of the way into this link.
    http://en.wikipedia.org/wiki/Electricity_meter
    An oven, elec. dryer or water heater may each take 20 A or so. Elec. heat by itself might pull 100 A.
    But whatever current you draw the voltage drop across the connections should be less than 5% of so of the drop across the 24" of cable.

    Checking the neutral connection is a little more complicated.
    Last edited: Dec 17, 2010
  10. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    We couldn't now, given the condition of the current load center, use it to test how many amps we are pulling on average. We have tripped the 100 amp breaker several times over the years. If we run the washer, dryer, hotwater heater, dishwasher, A.C., 3 computers, Tv, fridge and several other items, we easily pull more than 100 amps. Our electric bill in the summer months is around $360 a month. Could you imagine the surprise when our recent bill was $45. I'm loving this for the time being. Kids are spending less time watching tv and on the computer. But, we will need to get this fixed before too long.
  11. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    The old meter socket probably need to be upgraded to 200A also.

    A meter/panel combo would be your best bet. I've not heard of a 24" minimum height rule. If it does exist in your area, you would have to take out the guts of the old panel and use the enclosure for a junction box.


    Meter/panel combo mounted on a wall (typical installation in the SW).


    [​IMG]
  12. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    We talked to the POCO and they said the meter is already 200 amps and putting in a 200 amp box was fine. They upgraded the meters, some years back, to the digital ones. The current load center is way too small to gut and upgrade.

    GE sells a 125 amp outdoor lug box. They have a conversion kit that adds a 100 amp main breaker that locks down, making it a code compliant load center. I was considering this as an alternative but I was concerned that if we trip the breaker too many times it might damage it. I think I read that a breaker shouldn't have more than 80 percent of what the breaker's rated for in continuous current.

    How would any of you handle the wires being too short? Would you avoid splices and run new wire or would you use splices? And can I gut the current box and use it as a junction box? The chef electrical inspector didn't really answer my question on if it's ok with him if I do this.

    This is what I asked him.
    I live in a mobile home and my load center is on a pedestal with the meter. I'm wanting to upgrade to a 200 amp load center from a 100 amp. If I do this, then I will have to mount the box on the back side of the pedestal opposite the meter. The conductors coming from mobile home, shed and AC are just long enough to make it into the current box but will not make it to the new one, due to the two foot rule. My question is can I gut the current load center (which is basically a lug box) and use it as a junction box? And if so, is there anything I would have to modify on the box to make it code compliant? Such as securing the hinged cover with screws. Also, the wires coming from the mobile home are 2 awg aluminum. Can I use a but splice kit or do I have to use splice bolts?

    And this was his response.
    I would suggest that you replace the existing panel at the service with service rated equipment for 200 amps and reefed the existing circuits out of that equipment. If you are not sure at this I suggest that you contact an electrical contractor for advice.

    By refeed, does he mean run new wire? I would ask him, but the last sentence seems like he's not wanting to give advise. I wasn't seeking advise from him on how to do this. Just wanting to know if it's ok with him to use wire splices and the old box as a junction box. I know some inspectors can have pet peeves and wanted avoid one by checking with him first.
  13. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689

    This is probably the best advice he gave you. This is a relatively simple 3/4 -1 day job for a person with the right experience and tools but, IMO, this is not a DIY project.

    If the meter socket is rated for 200A you could mount a new panel to the right, tie it to the old panel with conduit/nipples and make whatever splices you need in the old panel (with the guts removed.)
  14. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Check the max main breaker size. Perhaps you could go to 125 amps and survive with some use modification.

    I have a mobile that kept tripping the old 100 amp breaker, tripped enough at low loads that I thought that it was tired and defective.

    Changing to a new 125 amp breaker solved the issue quick and cheap. took some work
    [to find the breaker] The wire and box were rated for 125 amps.

    Notice the corrosion and rust on your outdoor terminals. This is why no-corrode paste is so important outdoors!

    Part of the issue might be poor connections. The bus bar should be treated too if you go that route when the meter is pulled.
  15. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    I've replaced the breakers about three years ago. They cost more than all the parts to install a new 200 amp load center. I didn't replace the bus bar or put on any paste. That was were I messed up.

    The current box was installed in 1983, along with the home. The breakers were replaced by my dad a few years after they moved in because they went bad. My guess is he and the original installers didn't use any paste for it to have gone bad so many times. It's a Zinsco box and breakers. Not worth trying to keep.

    I'm a DIYer and hate having to pay someone else to do work. I've always fixed just about anything myself. If I hire someone, this will be only the second time I've had to do it. But, it's looking like I might have to bite the bullet on this one. I want to do it. But if I do something the inspector doesn't approve of, then I will run up the cost and delay the power getting turned on, once it's turned off. The question is, is it worth it to learn something new. Ignorance is not bliss.

    Not to mention that, I've heard of enough times where licensed electricians didn't do things right ether. I've seen it in automotive repair as well. Heck, I've seen were they've made things worse. So, if I do something wrong, I can learn from it. Were as if I hire someone, they get paid and I find out years later that they screwed up and I'm stuck with another bill.
    Last edited: Dec 19, 2010
  16. Bobelectric

    Bobelectric Electrical Contractor

    Messages:
    39
    Location:
    Eighty Four,Pa. 15330
    You got a real mess going on there. I can't see a ecg wire to a ground system, and the black and red conductors on a twin breaker,same leg spells trouble!
  17. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,874
    Location:
    Cave Creek, Arizona
    It is a Zinsco breaker, and the placement of the internal connector to the bus determines whether they are on the same or opposite legs. This one has the handles pegged together so they are for a 240 load, NOT tandem 120 volts.
  18. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    There are four wires coming from the house (ground = black with green tape) and the shed (ground = green wire). Three from the A.C. I'm not sure what you mean by ecg?

    Are you talking about the ground to earth? As far as I can see, there is a ground wire going from the meter down the inside of the pole into the ground. Not sure how many grounding rods there are. I have to check with the POCO to see if they were the ones who installed it, since it does run from the meter.

    Three years ago, when I changed the breakers, the inspector only required that I lock down the main breaker to pass inspection. Everything else checked out ok. I had my dad machine a steel bracket to lock down the main and it passed. So, I'm guessing that the box is grounded to earth, or it wouldn't pass inspection.
    Last edited: Dec 19, 2010
  19. Mindz i

    Mindz i New Member

    Messages:
    11
    Location:
    Florida
    Here's an example on the net I found, that shows what I had happen to my main breaker the last time.
    [​IMG]
  20. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,874
    Location:
    Cave Creek, Arizona
    That brand of breaker was NOT one of the premium ones. IF the "horseshoe" got heated, (and it was sort of a self fulfilling prophecy when it did, because the connection with the bus would get loose, causing it to heat, and then the heat would make the connection looser as the metal lost its temper), it lost contact with the bus and arced causing the damage you see there. But the modern panel will have the main breaker integral with the power bus, so the main wires connect to the panel lugs, NOT the main breaker connectors.
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