Electrical Wiring in the Home/100 amp panel box

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Question
QUESTION: I am installing a 100 amp panel box in a portable work trailor that will be fed by 2 sources. This box will only have 2- 20 amp breakers in it. One for 4 outlets and 1 for 3 lights. The feeds will be a 110 volt heavy duty extension cord and the other at rare times will be hard wired and another source. I want to make sure the wiring can handle both feeds at any given time. What wires will go in the 2 lugs on each side on the main breaker and which wire will go into the neutral lug. There will never be any need for 220 volts. Do I need a separate ground bar as well? Thanks in advance.. You may be saving my job!

David

ANSWER: Robert Wilber
Licensed Philadelphia Electrician
Philadelphia License # 3516 - 16765
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LIFE SAFETY WARNING! [disclaimer]
Electricity is dangerous!
You can be injured or killed!
Improper installations can cause fire, injury and death!
Are you qualified to do this work?
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National Electrical Code definition, NFPA 70 2008 Article 100: Qualified Person. "One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved."
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Electricity is fire in a box!
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Always check with the local “Authority Having Jurisdiction” for an official interpretation before making installation decisions.
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In Philadelphia, it is unlawful for anyone except an individual licensed by the City of Philadelphia to install electrical equipment and wiring.
Homeowners are not allowed to install wiring.
The owner of any property wherein any such installation is discovered shall be issued a violation by the Department of Licenses and Inspections.
The limited exceptions include replacing devices and fixtures at existing outlets.
Contact the Department of Licenses and Inspections for more information.
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You are more likely to be killed by 120 volts than any other voltage [120 volts creates the PERFECT fatal current through the human body's electrical resistance!]
TURN THE POWER OFF WHEN WORKING!
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LIFE SAFETY WARNING! [disclaimer]
This information is provided for the use of parties as they see fit!
I am not responsible for the application of this information by any party, including those lacking sufficient skill or knowledge to perform these steps safely and any hazard created is the SOLE responsibility of the user.
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What you are describing requires a transfer switch, which is basically a three-way switch on steroids.
This is a sub-panel - that means an isolated neutral bar. [that means no local direct connection to ground]
Check with your local AHJ!

---------- FOLLOW-UP ----------

QUESTION: Now I am just feeding with the 110 perm. line. 1 wire to the neutral, 1 to the ground bar and 1 to the main. Right?

Answer
Sounds more or less right, but I can't see what you are doing or how you are doing it.
Don't you have electricians on the site?
*
LIFE SAFETY WARNING! [disclaimer]
This information is provided for the use of parties as they see fit!
I am not responsible for the application of this information by any party, including those lacking sufficient skill or knowledge to perform these steps safely and any hazard created is the SOLE responsibility of the user.
About Electrical Wiring in the Home
This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

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Robert Wilber

Expertise

Licensed Philadelphia electrician serving Delaware, Chester, Montgomery and Philadelphia County in Pennsylvania. I install and repair residential, commercial and industrial wiring and lighting. Troubleshooting and repair of problems that stump other people is my favorite. I am willing to help people figure out why things don`t work. I understand motor controls, transformers and machine wiring. I do not teach basics to novices or do free design work.

Experience

Experience in the area I have 44 years experience in residential, commercial and industrial electrical construction and repair, 480 volts and below. This is not to be confused with one week repeated two thousand times.

Education/Credentials
44 years experience in residential, commercial and industrial electrical construction and repair

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