Questions for the Electrical Guru

Discussion in 'Electrical Forum discussion & Blog' started by tvl, Nov 28, 2008.

  1. tvl

    tvl Member

    Messages:
    139
    Location:
    South Carolina
    On the outside of our home is an electrical circuit breaker panel used for our Heat Pump. The outside panel is located about 45 feet downstream from the main circuit breaker panel located inside of the home. The outside panel is fed with a 100 amp double pole circuit breaker using # 2 aluminum wire. Since the outside panel is being used to feed 220 volt service to the heat pump, only 2 conductor with a ground was used to complete the wiring.

    Click HERE to view the inside of the outside electrical panel.
    [​IMG]

    Now for my questions:

    During the summer we built a deck on the rear of our home. One edge of the deck is located just 5 feet from the outside electrical panel. And you guessed it, I want to run a single 15 amp breaker from this electrical panel to power some LED rope lights around the deck.

    Looking at the photo mentioned above, you can see that the outside panel has only one grounding bus. If I install a 15 amp - 120 volt circuit in this box, I will have to use the single ground bus for my ground wire AND neutral wire. This scenario will work, but:

    1- Is it acceptable?
    2- Would it be considerd a fire hazard?????
    3- The main box located inside the home shares the ground bus for BOTH the neutrasl AND ground wires. Why not outside also? What's the difference?

    And finally, because I believe this would not be considered NEC recommended, could I simply run a neutral wire from the main panel inside the home to the outside panel for the single 15 amp - 120 volt circuit?

    Thanks so much!
    Last edited by a moderator: Nov 29, 2008
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    At a sub-panel, the ground bus and the neutral bus are NOT connected together. The reason is, you do not want the ground wire to share the neutral current on its way back to the main panel. This would be unsafe. An earlier post today showed a news report about a child killed by this idea....current in the ground wire .

    I will leave it to the electrical pros to tell you how to fix this.
  3. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina

    Simple fix

    hire an electrician before you kill your self
  4. Johnny C

    Johnny C Electrician

    Messages:
    23
    Location:
    Mass. & now Virginia Beach, VA
    Question for Electrical Guru

    Based on 2005 NEC.
    Based on the photo provided, there are a few Code violations.
    1. Section 312.5 requires a connector or nipple with a bushing to proved protecion of the conductors feeding the panel.
    2. Since this is a sub-panel on the load-side of the service disconnect, the neutral terminal bar and equipment terminal bar must be isolated from each other. No equip. grnding conductors connected to the neutral. See Section 250.142(B).
    Last edited: Nov 28, 2008
  5. tvl

    tvl Member

    Messages:
    139
    Location:
    South Carolina
    With all due respect, and as mentioned by another poster, this box already has a couple of code violations which I will take care of AND it was installed by an licensed electrician. It appears an electrician is not always "THE" answer. Just look at the post titled "DIY Electrical".

    Our home is 30 years old ............... maybe the code was more lenient back then and this was considered appropriate???
  6. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina

    With all due respect as you mentioned in your original post you were asking about using the equipment grounding conductor as the return for a 120 volt circuit.

    What makes you think you have the knowledge to repair what is there now?
  7. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    That panel was not installed by an electrician. It was installed by a HACK!
    If he called himself an electrician then that is just false advertising.

    There are several grave violations. It's not that the connector needs a bushing. There is NO cable connector even there. There is also a double tap on the main lugs.
    That panel would be legal as a "240v only" panel. They used SEU cable which has a neutral, but no ground. This bare NEUTRAL can be used as a ground, but NOT both when feeding a sub-panel.
    The problem in this case is the white neutral on the bar. This is the neutral wire from that non-compliant double tap.

    I would seriously consider hiring a REAL electrician to fix all those violations and re-feed that panel with SER and install a separate ground bar to make that a proper 120/240v panel before you go any further.
  8. jar546

    jar546 In the Trades

    Messages:
    432
    Location:
    USA
    * Should have been fed with a 4 wire cable.
    * No strain relief bushing at feeder service.
    * Neutrals and grounds need to be separated.
    * Equipment grounding bar bonded to the panel needs to be added.
    * Neutrals need to be isolated from the panel frame and equipment grounds.
    * The main lugs are not rated for the taps that are there.

    This is a disaster waiting to happen. Get it fixed professionally.
  9. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    John C.
    Are you saying that 312.5(C) allows a nipple to enter the back of a disconnect for a cable that has totally nonmetallic sheathing to enter?

    Although the disconnect has no connector which is a violation of 312.5(C) is there a problem with the NM cables that are exiting the panel in what looks like LFNC?
  10. tvl

    tvl Member

    Messages:
    139
    Location:
    South Carolina
    First, I do thank all who have replied ............ the input is what I was looking for!

    Second, trust me, I do want to do what is correct, thus the reason for my questions. All of the work between the outside box and the main electrical panel inside the home was done at the time of construction (1977) by a local electrical contractor, as was most of the other homes in our subdivision.

    And last, the white wire on the ground bus, as well as the two black wires underneath the main lugs are from a Joslyn secondary surge protector (installed in the late 70's) similar to the one shown at the following link. Only difference is ours is an older model and has only 3 wires.

    http://s75.photobucket.com/albums/i316/n44491/?action=view&current=joslyn.jpg
    Last edited: Nov 29, 2008
  11. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    Yes, and if you could see the instructions you would see that they say to connect the two hots to a two pole breaker, NOT under the main lugs.
  12. tvl

    tvl Member

    Messages:
    139
    Location:
    South Carolina
    Thanks Speedy!

    Once again, I didn't do the work, but I will correct the issue.

    Therefore, if I understand your response, the two black wires will be placed underneath the lugs of the 30 amp breaker which feeds the heat pump compressor. There will be no protection for the heat strips using this method, but maybe not necessary?

    You did not mention the white wire coming from the surge protector. Therefore, I am assuming it was placed correctly!

    I have decided NOT to use the box for adding a single 120 volt circuit. However, I will correct these issues everyone has mentioned, I see no reason for me not to do the work as the solutions mentioned are very doable.
  13. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    Why do you say this???
    Those units are not directional, nor is there line or load. They just absorb a spike regardless of where they are.
    And putting the wires under the A/C breaker is also a violation, unless the breaker is designed to take two wires.
    Those things should be on their own breaker.

    The white carries no load or current, so it can be called a neutral or ground. I don't see a problem connecting it to a ground bar. The only restriction would be what the instructions say.
  14. tvl

    tvl Member

    Messages:
    139
    Location:
    South Carolina
    Sorry Speedy, I simply misunderstood your previous response. However, I was able to locate the Joslyn documentation for the unit I have. It is dated June 1973.

    Please click on the following link to see a photo of a commom installation at a service entrance:

    http://s75.photobucket.com/albums/i316/n44491/?action=view&current=JoslynSP.jpg

    I NOW understand that the NEC does not allow two terminals to be underneath the same lug as in my installation. However, based on the photo, I do not see any reason to wire this device to a dedicated breaker?????
  15. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    That device in your last link is MEANT to be spliced right to the service drop given that the splices are approved for it.
    The kind that go into a knockout in a panel should be on their own breaker.
  16. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,559
    Location:
    North Carolina
    They ain't worth a dime unless they are installed at the service with the grounded conductor connected to the grounding electrode conductor.
  17. TheElectricalGuru

    TheElectricalGuru National Electrical Code Expert/Speaker/Educator

    Messages:
    11
    Now see.....the BOLD underlined verbiage above worries me more than the DIYer itself.....
  18. jar546

    jar546 In the Trades

    Messages:
    432
    Location:
    USA
    Forgive me oh your Guruness for replying to a thread started for you. I held off until others broke the silence while waiting for you to reply. For that I am sorry.

    Now quiet please, for the Guru shall speaketh............

    ;)
  19. wallyworld

    wallyworld New Member

    Messages:
    21
    If its only feeding a 230 volt load why does it have to be a 4 wire cable?
  20. jar546

    jar546 In the Trades

    Messages:
    432
    Location:
    USA
    It is not just feeding a 230 load. Look at the white neutral wire and the illegal taps off of the lugs. It is feeding a 120 circuit somewhere.

    The whole thing needs to be redone.

    If it was a dedicated 240 panel then no, it would not need to be a 4 wire although that would cause some other bonding problems.
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