Timeline for Protecting malfunctions in relays which operate roller shutters (motor, inductive load)
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Feb 7, 2019 at 13:55 | comment | added | thece | Ok, so there are two possible explanations for the "fusing". Either the relays are faulty and bad constructed (maybe serve as protection relays and not control, so they are designed for few triggers every year) or the overvoltage and arc fused them together. If it's the latter, try installing a MOV across the motor terminals and maybe try some other snubbers on the relay. Other than that, there is not any "dirty-cheap" solution. Hope you find a way | |
| Feb 5, 2019 at 17:43 | comment | added | thece | Forget the flywheel diode I mentioned (I forgot we are dealing with AC motors). I don't know if your schematic the same with the actual wiring, but consider you set Q1=HIGH -> shutters will do up. On the other hand, if you set Q2=HIGH (and Q1=LOW) nothing will happen, since there is not any closed loop for the current. Anyway, at the moment I cannot think of any reason for the relay contacts to fuse... If come up with something I will inform you | |
| Feb 5, 2019 at 16:46 | comment | added | MariusSiuram | @thece The box should should be motors similar to this other question. I have no idea of the insides of the motor, other than they are prepared to be 220VAC. I thought that flywheel diode are only for DC motors, am I wrong? I assume that there is the overvoltage you mention, and that is precisely what I was hoping to solve with the snubber. Q1 and Q2 are related to the digital control. I hope it is safe to ignore them, given that they are isolated from the power lines. | |
| Feb 5, 2019 at 16:32 | comment | added | thece | @MariusSiuram I don't understand what's inside the box. And who's the role of Q1 Q2? Q1 is on/off and Q2 up/down? Please explain. Other than that 16A are sufficient enough to drive the motors. But, do the motors have flywheel diode? or every time you stop them, there is an overvoltage due to the instantaneous interruption of the windings? | |
| Feb 5, 2019 at 10:03 | history | edited | MariusSiuram | CC BY-SA 4.0 |
fixed schematic (cover -> roller shutter motors)
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| Feb 5, 2019 at 9:49 | comment | added | MariusSiuram | @JRE thanks! I completely forgot the term (non native speaker here). Updated the answer with some additional information about the relays | |
| Feb 5, 2019 at 9:48 | history | edited | MariusSiuram | CC BY-SA 4.0 |
adding some info and correcting cover -> roller shutter
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| Feb 5, 2019 at 9:44 | comment | added | MariusSiuram | @thece they are 16A rated 5V relays. Why the relays cannot be connected in series? You mean that having them in series is the root of my problem, or there is some mistake that I am not seeing? The PCB is working, except the fused contacts problem. And note that "fused relay" is solved by "slight percussive maintenance", which means that it's not "very fused", if that makes sense... | |
| Feb 5, 2019 at 8:21 | comment | added | JRE | Those are "roller shutters." | |
| Feb 5, 2019 at 8:19 | comment | added | thece | Fused relay contacts is a sign of overcurrent. What is the rated current of the relays and the power of the motors? Also your schematic is wrong. Relays cannot be connected in series. What does the "cover" box represents? | |
| Feb 5, 2019 at 7:45 | review | First posts | |||
| Feb 5, 2019 at 7:51 | |||||
| Feb 5, 2019 at 7:44 | history | asked | MariusSiuram | CC BY-SA 4.0 |