Gate automation system - Motors open but do not close.

[profaz]

Hi everyone!
My gate automation system doesn't work properly. The gate has two motors, you can see one of them in the picture below and the automation system is a BFT, the motherboard is an ARIES and where I believe the problem is. The manual for the motherboard is this www.bft.cz/privat/navody/ridici_jedn/en/ARIES.pdf

• During the opening phase, the two motors work correctly and the gate opens.
  
• During the closing phase one motor keeps opening; the second doesn't do anything.

Everything else seems to work properly (photocells, etc... ). I switched the board connections of the two motors and the behavior switched too, so it is not a problem of the motors.

The problem seems to be very simple but I cannot figure out which component can cause this bad behavior.

What I did:

• I changed the 4 relays (k2, k5, k3 and k7) that seemed to be damaged with new ones...but the old ones were actually working correctly
• I changed the two big capacitor, but nothing changed.
• In Y1 (maybe it is more clear in the pictures below) there is a Microcontroller Philips P87C750EBPN (with a label on top "POLLUCE v.ersion 2.51) that I guess is the "brain" of the board, and probably it is not damaged. In fact, I found in my garage an old board that was substituted many years ago. So, I took from the old board the microcontroller and I put it in the installed board and the gate didn't open nor close (it only clicked when the button was pressed).
  Then I installed the old board WITH the microcontroller of the newer one and the gate opened and closed a couple of times...then stopped completely (I deduced that the old board had some additional issues, not only the broken microcontroller).

Can you understand from the pictures above and in the link below what component could cause this problematic behavior during the closure phase?


Thank you in advance for any suggestion.
In the link below, you can find a gallery with pictures of the board, I hope you can easily see how it works:
http://imgur.com/a/m8Mh2

Please let me know if you need more details/pictures to discover what is the issue.

 

[Tha fios agaibh]

Provided you know and understand the dangers involved with working around live energized circuits, I'd temporarily jumper pin 13 and 16 to eliminate possibility that the photo eye signal is bouncing during closing.
Could also be that there is mechanical bind causing motor torque to exceed its max settings.

 

[profaz]

Thank you very much for your suggestions, because of the bad weather I cannot try them. I'll ketch you up as soon as I test them. Thanks again!

 

[Alec_t]

If you've eliminated the relays as suspects, then my guess would be that the ULN2003A drives them but is faulty.

 

[profaz]

Provided you know and understand the dangers involved with working around live energized circuits, I'd temporarily jumper pin 13 and 16 to eliminate possibility that the photo eye signal is bouncing during closing.
Could also be that there is mechanical bind causing motor torque to exceed its max settings.

@Tha fios agaibh I did it: bridged the 13 and 16, but nothing changed. I also put the torque to the maximum (T4) and unlocked the motors from the doors so that they had no resistance at all. Nothing Changed.
I really think there is some issue at the electronics level.

@Alec_t Thanks for the suggestion, I changed all but two relays: the big one K6, since I couldn't find a 16A relay so far. But it had no visible signs of damage. Also, the GOOD SKY on the right (K1) is a relay, but I thought that going on blindly changing all the elements wouldn't be a promising strategy. What do you suggest? Probably the next week I can substitute the ULN2003A with a new one.

 

[Alec_t]

Relays may look ok, but if the contacts are burnt/welded you will have problems. Can you check that the contacts open/close as they should? My only suggestion would be to replace the ULN2003, but of course there's no guarantee that will fix things.

 

[Tha fios agaibh]

I don't follow the operation of this.
Do both motors operate to open the gate, and then both motors change rotation to close it?
What I'd do is remove the cover on the the two relays controlling the motors. Then wearing proper PPE, carefully actuate the relay manually to verify which relay controls which motor. Be careful not to actuate both at the same time, as it may cause a short circuit.
Once you know what relay should be actuated to close the gate, we can then determine why the relay is not energized or why its not passing power.

I'm with AlecT, that a relay contact may be welded together.
I see carbon marks blackening the plastic relay covers.

 

[Bluejets]

Seems there are 2 motors, one for each gate half.

I believe you were on the right track initially when you swapped over the controls to the opposite motors and the fault followed.
On a good day, most problems with electronics stem from the mechanical sections such as relays, switches, connections etc.

If you have a working half it makes life a bit easier as you can compare between the working and not working as stated above.

 

[profaz]

The gate has two electromechanical actuators (if I'm not wrong), yes one for each gate half.

@Tha fios agaibh Well, the gate opens (both the motors rotate correctly). During the closing phase, one gate doesn't close but open (so it works in the opposite way it should). The other one, stand still. It doesn't emit any sound, as it was in pause. Actually, the new relays are solid state, and I guess I cannot remove the cover. This technique actually scares me a bit.

My guess was that this inversion of the behavior of one of the two motors was the key to understand where the problem could be.
Do you know how the motors "know" the direction? Meaning: There are three wires starting from the board do you know were I can find references to which kind of "electricity" dives them? I read 230V on them,and I guess they are quite standard.

@Bluejets Yes, I should find which part is devoted to the closing of the gate and compare it with the one that opens and works correctly, but I cannot figure it out yet.

 

[Bluejets]

Think the best idea would be to get a drawing of the layout at least.
Can you provide a pic of the motors?

 

[profaz]

Pardon me, what do you mean with the layout?
Above, you can find the picture of just one of the two motors.

I dont have a picture of the other one.
The label on it is almost impossible to read because it is quite old. What I could grasp was 230V and PROTON the name of the model I guess.

 

[Bluejets]

Layout = circuit diagram.
Is the #11 pic all you can provide of the motor?

 

[Bluejets]

Just looked up a web site ....says motor is 120-24 VDC (for that particular operator at least)
This would assume just reversing connection would reverse the motor. The 120-24 has me a bit baffled though.
In most instances this usually means any voltage between 120 and 24 would work, BUT usually this is written the other way around AND not normally applicable to motors.
Having said that there is no reason why a 120V DC motor may not run (all-be-it rather reduced output)
So your 230v AC may be the supply to the main unit..???
It may also be that there are controls embedded in the motor(actuator) casings.

https://bftgateopeners.com/store/bft-phobos-bt-l-single-swing-gate-operator-kit-kr935245-00001p.html

Actuators are one of the mechanical things I referred to earlier and may be worth a look-see
Given that .......it's mechanical
it's usually open to the weather and ants and whatever to some degree
any rubber seals may have deteriorated over the years allowing one or more of the above

 

[Bluejets]

Power supply: 120V - 24 Vdc Motor

Think I miss read the specs..... one I linked to is apparently 120v mains suppy with a 24V DC motor

 

[profaz]

It seems to me that the phobos BT model works at 24V but the AC model works at 230V. Mine is way older, the board is called ARIES. On the manual http://manuals.easygates.co.uk/PDF/bft/AriesPEnglish02-02.pdf

Power supply: 230V±10% 50Hz
Absorption on empty:.................................................................0.5A max
Output power for accessories:..........................................24V~ 6VA max
Max relay current:................................................................................8A
Max power of motors:...............................................................300 W x 2
Torque limiter:.................................................Self-transformer with 4 pos
Limit switch:................................................................Adjustable run time
Panel dimensions:.........................................................................See fig.1
Cabinet protection:............................................................................IP55
Working temperature:...............................................................-20 +55°C

If the motors are considered accessories, it is 24V ... unofrtunately, the description of the pins doesn't report the voltage for the motors
7-8-9 Motor M1 connection - 8 common, 7-9 start.
10-11-12 Motor M2(r) connection - 11 common, 10-12 start.
Since pins from 5 to 12 are divided from those 13 - 23, and the blinker works at 230V I guess that motors work with 230V or at least at high voltages.

The motor closer I just found is this one
http://manuals.easygates.co.uk/wp-content/uploads/2013/02/PHOBOS.pdf

So I can invert the two pins to invert the motion.

 

[Tha fios agaibh]

Do you know how the motors "know" the direction? Meaning: There are three wires starting from the board do you know were I can find references to which kind of "electricity" dives them? I read 230V on them

Depending on motor type, rotation is determined by changing the start winding connections on AC or the DC supply polarity.

Take a voltage reading between common (8) and one of the start terms (7,9) make note of direction of motor.
In other words, I'm expecting 7 hot and 8 neutral (blue) for one direction. And 9 hot to turn it the other way with respect to the common 8.

BTW, what wire colors do you have from the motor? If its brown, blue,green w yellow stripe. This is not a reversing AC motor. Their is a possibility that the actuator works on a cam and the motor only has one direction.
The strange thing to me is that I don't see any limit switches for opened/closed.

 

[Tha fios agaibh]

Yes got your link, blue (8) and black (7 or 9) is one direction and blue and brown is the other.
Its 230v AC.
First thing I'd check is the capacitor.
The limit switches are internal

 

[profaz]

Capacitors have been replaced too. Actually, then I put back the old ones because with the new ones nothing changed (and the two new ones are too big and doesn't fit inside the box).
With Capacitors I mean the two big ones 6.3uF.

 

[Tha fios agaibh]

I'd look for a pattern like; open cycle powers 7 but not 9 with respect to 8 (common). Then see if it follows with the other side; power on 10 but not 12 with respect to 11. Make note of which terminal energizes with open/close cycle and which relay energizes.
If you have a loaded meter, that'd be better than a DVM for testing purposes.

 

[Bluejets]

Yes, seen motors like that before. Not all that common but the 3 wires you mentioned before threw me, should be 4 with the earth wire really.
Limited by what we can see in the pics.
Something definetly not switching properly by the looks and more than likely a relay.
One might think the motor may have a problem also but you ruled that out before when you did a "changeover".