Electric Roller Blind Motors - Thermal Trip
We are occasionally contacted by customers who are programming their electric roller blinds and during the programming process their blind stop responding. I thought it would be useful to write an article explaining why this is likely to be.
Mains operated roller blinds have what is known as a "Thermal Trip" incorporated into them. Consider that once installed and configured, roller blinds motors are typically used only periodically in short burts (1 up or down cycle, lasting 1 minute, maybe).
During the programming process, the blinds can be used quite intensively for a prolonged period of time. Each the motor is used, it generates a small amount of heat. If it is used intensively for longer periods, then this heat can build up within the motor and the aluminium roller blind tube. You might notice that the motor itself is too hot to touch. Or if the motor is inserted within the roller blind tube, that the roller blind tube is also warm.
As a safety feature, the motor's thermal trip is designed to kick in conservatively to prevent the motor from overheating. Because the motor is housed in an aluminium tube, it can take a while to fully cool down.
As an example, if you use your blind intensively for say 30 minutes during programming, you may find that it stops working because of the thermal trip. You may come back to it 30 minutes later, use it for a few mins and it may trip again after another period of intense usage/programming. This is because the motor hasn't had chance to cool down adequately. If this is the case, then I'd probably come back to it later in the day to give it chance to cool.
This is how all brands of tubular motors are designed to operate. It is an essential and basic safety feature.
Typically as you become more experienced in programming roller blinds, you will find that the amount of time required to correctly configure your blind reduces massively and therefore the likihood of the motor heating up to the extent that it activates the thermal trip is less. And of course once the blind has been programmed fully, we'd not really expect that it would often be operated so intensively as to cause the thermal trip to be activated.
I hope this explains how thermal trips are used in roller blind motors.