How to Replace 1 Lamp Rapid Start Ballast with 2 Lamp Rapid Start

A 1 lamp rapid start (series) ballast can be hard to find, but it can be replaced with a 2 lamp rapid start ballast. Here is how a 2 lamp ballast is wired to a 1 lamp fixture.

1 Lamp Rapid Start Ballast Diagrams

Factory wiring

1 Lamp Rapid Start Ballast Replaced with 2 Lamp Rapid Start Ballast Diagram

1 Lamp Series Ballast Lampholder Diagram

The ballast blue wires connect to one end of the lamp, the red wires connect to the other side. The common yellow wires are capped with small wire connectors.

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