Applies To
Intermatic T100 Series Mechanical Time Switches.
Question / Problem
Can I use an Intermatic mechanical time switch to control my pool pump, and which model should I use?
Answer
Yes. Intermatic T100 Series mechanical time switches are an excellent choice for controlling residential pool pump motors on a timed schedule. The timer turns the pump ON and OFF at set times each day using adjustable trippers on a 24-hour dial, which helps maintain water circulation and filtration while reducing energy costs by running the pump only when needed.
Selecting the Correct Model
The correct T100 Series model depends on the voltage and phase of your pool pump motor circuit:
| Pump Circuit | Switch Type | Recommended Model |
|---|---|---|
| 120 VAC single-phase | SPST | T101R, T101P, T101R3, T101P3 |
| 208-277 VAC single-phase | DPST | T104R, T104P, T104R3, T104P3 |
| 240 VAC single-phase | DPST | T104R, T104P, T104R3, T104P3 |
Each model is available with different enclosure options: R suffix for an outdoor Type 3R metal enclosure (gray), P suffix for an outdoor Type 3R plastic enclosure (gray), R3 suffix for an outdoor Type 3R metal enclosure (beige) and P3 suffix for an outdoor Type 3R plastic enclosure (beige). For pool and spa applications, use an R, P, R3 or P3 suffix model with the outdoor Type 3R enclosure appropriate for the installation.
How the Timer Controls the Pump
The T100 Series uses a motor-driven 24-hour dial with removable ON and OFF trippers. Each tripper pair defines a run period. When the dial reaches an ON tripper, the timer closes the internal switch contacts and energizes the pump motor. When the dial reaches an OFF tripper, the contacts open and the pump stops. This schedule repeats every 24 hours.
Tips / Additional Notes
- Most residential pool pumps should run eight to 12 hours per day, depending on pool volume, pump speed and local conditions. Set the trippers to run the pump during off-peak energy hours if your utility offers time-of-use rates.
- Verify that the pump motor does not exceed the timer contact rating. Refer to the technical data sheet for your model for specific load ratings. For motors larger than the timer rating, use the timer to control a motor contactor rated for the pump.
- For outdoor installations, use a Type 3R-rated enclosure (R or P suffix) to protect the timer mechanism from rain and moisture.
- For electronic scheduling with Astronomic and holiday features, consider Intermatic PE Series Wi-Fi Timers, which are specifically designed for pool and spa applications and provide app-based scheduling through the Intermatic Connect app.