Hi,
I experienced a serious issue with my 2M dome last night. As part of normal operation, the bad weather configuration closed the shutter. However, the shutter motor did not stop, even after the shutter was closed, causing really loud banging noises (waking up the neighbors!) as the motor tried to still move the shutter!
Last night I simply cut the power, but now I am trying to investigate what happened, and again, turning on power leads to the shutter motor trying to close an already closed shutter – even though it is already registered as closed (see screenshot).
Right now I have power on the dome, but have disconnected the plug for power to the motor itself, so that it cannot activate.
I would really appreciate some help on what might be happening here, and what can lead to the motor being activated even if the shutter is reported as „closed”
Please check the wires from the card to Limit Switch Close. It’s also worth manually checking the operation of the Close sensor itself a few times (although the uploaded screenshot shows that the sensor works).
If that doesn’t help, send the card along with the motor and the wires to the motor and limit switch to us for repair.
The sensor works, but seems to only work sporadically. I have manually tried to operate both the Close and the Open switch, and they feel very different.
The Open switch has a distinct clicking sound every time it is moved back or forth, and you can kind of „feel” the click through the switch.
The Close switch sometimes makes the same clicking sound, and in these cases feel like the Open switch. However, sometimes I can move the Close switch with no sound and nothing felt – and in these cases the software reports shutter state „Stopped” even if it is closed.
It seems plausible, that the close switch is defect.
How do I go about replacing it?
Also, can anything be done to avoid or detect this situation? The motors are so strong that neighbors on the next street woke up from the sound of the motor grinding against the shutter rail, and the entire dome was shaking.
You can buy it via our WWW shop:
Limit Switch ScopeDome
one more think, check small inbus screw on limit switch arm.
I’m not sure what the „inbus screw on limit switch arm” is?
In any case, I think I will replace the limit switch, but am still wondering about what additional safety can be put in place. I know there is a timer that stops the motor after 50s, but that does not help because the weather-safety mechanism will just keep activating the motor as long as weather is bad and it does not thing the shutter is closed.
Encoder limits
From what I read in the manual, it sounds like there is an encoder also on the shutter motor. If so, would it be possible to add a safety option, so that the motor cannot be activated to try and move the shutter beyond min/max encoder values?
Redundant limit switches
I am considering if one could add 2 limit switches in serial. Currently there is a LS on the right side of the shutter. If an additional was placed on the left, and cabled so that it was in serial with the other, then I am thinking that as long as just 1 LS activates the connection would be broken and the motor stopped. This way a failure would require both LS’es to be defect, which should be much less likely to ever happen. What do you think?
Thanks,
Christian
Look on this picture.
Encoder for shutter drive is optional, you do not have it.
An additional switch limit can be added. However, in my opinion, it is not necessary. Out of nearly 1000 domes we have produced, this is the second time I have seen any problem with this component. They do not break.
Thanks for the picture – I tried the inbus screw, but it does not move. It actually looks like it is rusted, so it may simply be rusted in place.
About the additional switch: I don’t doubt you feel they don’t break – but mine did fail, and the consequences when it fails are potentially big. If my neighbor had not waken me up, I’m pretty sure something would have been broken by morning – the whole dome was shaking from the power of the motor trying to move the already closed shutter. Since a switch only costs a few euro, and all it really takes to make it redundant is one additional switch and a little extra wire I think it would at least be a nice option to be able to purchase. It is less important for the Open switch. The problem here was that even if the motor stopped after 50 seconds, the weather safety mechanism contined to activate the motor again, since it was cloudy and the shutter did not report „closed” – this issue would not happen for the „open” position.
Finally about the encoders. Perhaps you’re right, but looking at the „shutter” tab there is a „Current clk” value for my shutter that shows 103 when fully open as in the first screenshot, and the second screenshot shows it half closed at clk value 48 – so something in the driver must have a counter indicating where the shutter is. Could this not be used to have a safety flag one might enable, that would disallow commands activating the motor to move beyond a min/max interval?
Thanks for you answers,
Christian
This is a software counter not a hardware (it works on time meashure) – it is only used to show the approximate position of the flap for the ASCOM platform. Cannot be used instead as limit switch. Its value depends on the performance of the windows system and can change.
if you want to add additional limit swich here you have diagram:
