Linear Dial Settings on Time Delay Relays

Issue:

Is the dial setting on your time delay relays linear? How do I find 10 seconds with a range of 1-30 seconds?

Solution/Resolution:

Since most time delay relays use a potentiometer to adjust the time delay, the actual dial setting is not linear. Any markings along the dial are normally for reference only. To find a 10 second delay within a 1-30 second range, you can approximate the position as one-third between “MIN” and “MAX”. But this is just a starting point. You must check the actual delay and then tweak it by adjusting the knob to finally end up with the 10 second delay you need.

If initial setting accuracy is desired, consider using a time delay relay with digital setting capability instead of analog-set, such as the TD-7, TD-8 or TAD Series products from Macromatic.