Replace heater toggle switches with timer switches - brittag/maintenance GitHub Wiki

Aspect	Info
Context	Small commercial space
Date started	2024-11
Date finished	2024-12
Status	Complete
Summary of outcome	Success

Background

Small commercial space had overhead electric radiant heater panels controlled by standard toggle switches.

Problem

People sometimes accidentally left the heaters on while the space was unoccupied, which caused expensive electricity bills. Posting notes and reminding people was not effective. We wanted to create a reliable system instead of relying on memory: make the heaters turn off automatically.

Approach

We decided to replace the toggle switches with timer switches. A person much more knowledgeable than me looked at the specifics of the situation and determined:

The heaters are connected to 20a DPST (double pole, single throw) switches. This fancy switch ("double pole") is necessary, because to get 208v, you are using two legs of the building’s electrical service, which both have to be switched simultaneously.

Most residential-grade (cheap) wall timers would not work because they are designed for only 120v, which is a "single pole" of the electrical service. For example, all the cheap ones for bathroom fans, etc, would not work.

This means you need “heavy duty” / industrial timer switches, which are more expensive and harder to source locally.

We decided to use Intermatic Spring Wound Countdown Timer, Decorator Style, 125-277 VAC, 50/60 Hz, DPST, 6 Hour Max, Without Hold ($75 on Amazon). The person determined that the specs were compatible, including the voltage, wattage, and amperage requirements. You can install them into existing toggle-style switchplates.

It is appropriate to have a qualified person install them.

Outcome

This worked!

Next steps

None