Stuck relays controlling blinds

Martijn Hemeryck

I have a similar issue on my unipi neuron L203 when trying to control blinds.

The blinds operate with 2 relays: one for up and one for down.

The specs mention a rated current of 0.49 A, so I figured it would be fine to drive them with the built-in relays. Given I got the issue on 2 blinds shortly after each other, I'm not so sure anymore whether I can actually use them to directly drive the blinds.

Even after powering down, I can measure (with a multimeter) that the 4 relays are still given contact -- so I'm fearing the worst, that the contacts really got stuck.

Is there anything I can do in this situation?

Thanks in advance

Martijn Hemeryck

Replying to my own question here:

Later in the day, after some back of forth switching of the relays I was able to get 3 of the 4 relays functioning again (the other one seems lost).

My guess is that it's probably not ideal to use the simple built-in relays to drive the motors directly, so my current thinking is to have a look at a set of external relays to drive the motors.

Petr Helebrant

Hi,
I would really recommend not to use built-in relays for the final load as it's not designed for high current peaks typical for starting motors and switching power supplies. This often causes that relay remains stuck in closed position forever.

My solution for this is that I am using built-in relays just to bring 24V operation power to another appropriate relays to control final load.

I can recommend relay arrays from GEYA to controll almost any home-stuff load. Big advantage of this solution is that you can change faulty relays any time and this time will probably happen in far future because they are protected from welding contacts together by fuses.

For heating elements I am using high load 1 or 3 phase contactors with 24V control power.

Hopefully this helps.

Martijn Hemeryck

@Petr-Helebrant Thanks for your reply.

in the end, I did indeed end up putting in a separate series of relays to control the blinds. I did use relays from Eltako though, which were a lot more expensive than the solution you did provide. Thanks anyways for the tip, I can imagine it to come in handy for a future project.