1 Lamp Ballast Wiring

Old 06-10-20, 06:48 PM
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1 Lamp Ballast Wiring

Hello Everyone,

I changed the ballast of a (1) lamp (F42T6) fixture. The old ballast was a magnetic rapid start ballast meant to power (1) F42T6 lamp. The new ballast is an electronic instant start ballast that works with many different lamp configurations including a (1) F42T6 lamp configuration. The new ballast is a Fulham Workhorse WH1-120-L. The old ballast was an Advance.

I could see from the lamp wiring diagram for the old ballast and the new ballast that there would have to be a change in the configuration. Also, the old ballast had (1) blue wire in addition to hot and neutral wires while the new ballast has (2) red wires and (1) yellow wire in addition to the hot and neutral wires. I have attached pictures of the old and new wiring diagrams. I checked how the wires that connected to the ballast attached to each socket. One socket has (1) red wire and the other socket has (2) white wires. I followed the new diagram and connected the new ballast's (2) red wires together and used a jumper to connect to the red wire coming from one socket. I then connected the (1) yellow wire from the new ballast to the (2) white wires coming from the other socket. As for the white and black wires that receive the feed of 120VAC, I connected those to the power source's wires.

My question and confusion is coming from the (2) white wires coming from the one socket. I connected them to the (1) yellow wire coming from the ballast believing they are acting as the common. I am not completely sure I did the wiring correctly, because the (2) white wires make me wonder if one should be capped or has a different purpose in the new configuration. I read the notes in the new wiring diagram, and it states the red wires are the power wires. Did I correctly wire the red and yellow wires to the respective red and white wires coming from the lampholder sockets for the new wiring configuration?
<img src="https://cimg4.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1124/how_i_wired_it_b2209a1e0f391ef50ca6c142f2eb7e4dbd64a37d.png" width="1999" height="1124"/>
This is how I wired it.

<img src="https://cimg4.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1280x1251/old_wiring_diagram_6db95125582688887f1dccf22244f70baf764771.png" width="1280" height="1251"/>
Old/Original Wiring Diagram
<img src="https://cimg8.ibsrv.net/gimg/www.doityourselft.com-vbulletin/960x1710/new_wiring_diagram_d3efe1522a3843f4cca50fe5824030c75b3cf2a6.jpg" width="960" height="1710"/>
New Wiring Diagram
Old 06-10-20, 09:19 PM
PJmax's Avatar
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A very confusing ballast. Very rarely are the hot line (red) wires connected together.
However..... the mfg does indicate that as correct.
Your diagram is correct.

With an electronic ballast...... you can use one or two pins at each end. If you have two wires on a socket..... combine them into one. If you only have one wire.... just use that one. You could spend the time to bridge the pins on the socket if there is only one wire but it's not needed.

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