A complete defrost program timer composed of just three basic components: frame, drive motor, and program modules. The drive motor module slides on to the end of the frame and is securely locked by a single captive hex bolt. Individual program modules slip into the frame and are secured by a spring-loaded clip bar.
In the field any drive module or program module can be removed and replaced without disassembling the timer or disturbing program settings.
Each program module has a 24-hour dial with time-of-day indication for initiation programming and a 2-hour dial for defrost duration control. Up to 12 operations per day are possible. The duration of defrost or the duration of backup defrost termination is 6 to 106 minutes.
Integral solenoid termination permits termination of defrost upon closure of an external pilot device, such as a thermostat or pressure switch.

• Up to 24 program modules can be driven by one motor

• Used with A87999 or A88099 frame modules and A876, A877 circuit modules