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Kevin
Kevin, Licensed Electrician
Category: Electrical
Satisfied Customers: 2951
Experience:  29 years as a Licensed Electrical Contractor in Illinois, 5 year college Electrical Instructor, Former Electrical Inspector, Diploma in Digital Electronics, Former Illinois Licensed Home Inspector
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I have A commercial building which has several old T 44 bulb

Customer Question

I have A commercial building which has several old T 44 bulb for us and fixtures. Many of them need ballast for repair the same decided to install complete retrofit prewired T8 four bulb fixtures. These are in a drop ceiling so installation of the fix is very easy. The old fixtures for Ted to Balis each and for Bob's had a conduit running to each with four wires one large black one small black one small white and green. New prewired T8 fixture as a quick disconnect which appears to maybe have a black and a white connection. What do I do with the second black wire if anything
Submitted: 1 year ago.
Category: Electrical
Expert:  Kevin replied 1 year ago.

Hello and welcome to Just Answer. My name is ***** ***** I will be happy to assist you with your electrical question.

1) Were both of the black wires spliced to the original ballast at each fixture or only 1 black wire spliced to the ballast hot wire?

2) Do all of the mentioned lighting fixtures reside on the same circuit breaker or 2 separate breakers?

3) Are the lights controlled by a circuit breaker or multiple wall switches?

Customer: replied 1 year ago.
1. Only 1 black wire to balast hot wire
2. 1 breaker
3 multi wall switches
Expert:  Kevin replied 1 year ago.

Thanks for the replies and confirmation.

1) A T8 ballast only requires 1 hot and 1 neutral connection. The T8 ballast also requires a ground connection.

2) Possibly, the 2nd black wire was installed as a switched loop conductor to control other downstream light fixtures? Another possibility is that the circuit was configured as a shared neutral circuit where a 2nd hot conductor is required if configured as such. Another possibility is that the 2nd black wire is an abandoned wire and is not in use.

3) Most likely, the circuit breaker will be a 20 amp. If a 20 amp breaker, the switched loop conductors will be sized as 12 AWG Copper unless the conduit run is lengthy and there were voltage drop issues that required a larger conductor. The switched loop wire that will splice to the new T8 ballast will be of the same wire size as that landing on the controlling circuit breaker.

4) Since you have a conduit system in place, gently tug on the 2nd black wire to determine where it extends to.

5) If the 2nd black wire just dead-ended and was not spliced to any other wires, then put a plastic wire nut on it as it won't be needed.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks.............Kevin:)

Expert:  Kevin replied 1 year ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks...............Kevin:)

Expert:  Kevin replied 1 year ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks...............Kevin:)

Expert:  Kevin replied 1 year ago.

If you have any additional questions, just let me know and I’ll be glad to answer them for you.

Otherwise, don’t forget to rate me before you log Off.

Thanks..............Kevin:)

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