Electrical 101

How to Replace Ballasts

Ballast wire (top) is 18 AWG. Line voltage wire (bottom) is 12 AWG.

Strip wires about 3/8 to ½ inch in length.

Use orange, yellow, or tan wire connector.

Ballast wires are 18 AWG. Use a blue wire connector for up to four 18 AWG wire connections.

Use orange wire connector for more than four 18 AWG wire connections.

Wire connector for ballast to lamp holder connections

Light fixtures from the factory are wired with the ballast wires connected directly to the lampholders. When changing a ballast, it is not feasible to disconnect and reconnect the wires from each lampholder. When done this way, the lampholders need to be removed from the fixture. It is simpler and faster to do the following:

1. Shut off power to the light fixture at the circuit breaker.

2. Cut the wires close to the old ballast and remove the ballast.

3. The wires from the new ballast are trimmed of excess length.

4. The new ballast and lampholder wire ends are stripped.

5. The new ballast wires are connected to the lampholder wires with wire connectors.

Ballast Wire Nuts

Twist-on wire connectors are also known as wire nuts. Wire-Nut® is a registered trademark of Ideal Industries and is the name of their commonly used twist-on wire connectors. Wire nuts come in different sizes depending on wire gauges and number of wires that are to be connected together. See Wire Connector page for more info.

Wire connector for line voltage wires

Wire connector for ballast to lamp holder connections

How to Replace a Fluorescent Ballast Video

Replace

Ballasts

Replace 1 Lamp Rapid Start with 2 Lamp Instant Start

Replace 1 Lamp Rapid Start with 2 Lamp Rapid Start

Replace 2 Lamp Instant Start

Replace 2 Lamp Rapid Start with Instant Start

Replace Alternate 2 Lamp Rapid Start with Instant Start

Replace 2 Lamp Rapid Start

Replace 3 Lamp Instant Start

Replace 3 Lamp Two Instant Start with One Instant Start

Replace 3 Lamp Rapid Start with Instant Start

Replace 3 Lamp Two Rapid Start with One Instant Start

Replace 3 Lamp Programmed Start with Instant Start

Replace 3 Lamp Programmed Start with Rapid Start

Replace 4 Lamp Instant Start

Replace 4 Lamp Two Rapid Start with One Instant Start

Replace 4 Lamp Rapid Start with Instant Start

How to Replace a Fluorescent Ballast Video

Ballast Wire Colors

If a ballast is replaced with the exact same type of ballast, the wire colors usually match. If an old T12 lamp magnetic ballast is replaced with a newer T8 lamp and electronic ballast, the colors will probably not match. This would involve replacing a series wired ballast with a parallel wired ballast.

When replacing a ballast where the wires colors don’t match, it is important to understand the ballast wiring concept. Just matching colors could cause a problem.