Design Interlock for two operations (Manual Switch and Automatic Switch)

Thread Starter

maitrey

Joined Sep 4, 2014
75
Approach it this way:

Condition - - - - - - - - - - - - - - - - - - - Results
1) manual switch is on. Remote off - - 1) Lights are on
2) manual switch is off. Remote on - - 2) Lights are on
3) manual switch is off. Remote - off - 3) Lights are off.
4) manual switch is on. Remote - is on 4) Lights are off.
Yes, this is the aim of this task.
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Approach it this way:

Condition - - - - - - - - - - - - - - - - - - - Results
1) manual switch is on. Remote off - - 1) Lights are on
2) manual switch is off. Remote on - - 2) Lights are on
3) manual switch is off. Remote - off - 3) Lights are off.
4) manual switch is on. Remote - is on 4) Lights are off.
Am I missing sometihing? I made two more connections from the Manual switch part to lamp and it works partially. I know that I still have to make connections to RY2 but getting an error when I do the same.
1585767994885.png
 

Tonyr1084

Joined Sep 24, 2015
6,455
Note: In this configuration it's possible one or both relays may be on for a prolonged period of time. They need to be properly rated in order to not overheat and possibly fail. Also, the switch contacts must be rated to handle the load. [edit] Corrected errors. SW1 = Manual SW2 = Remote
1585768787829.png1585768968557.png
 

Attachments

Last edited:

vu2nan

Joined Sep 11, 2014
189
Hello,

I am in the process of designing an interlock for two operations.

1. Operated by Manual Switch
2. Remotely through an Automatic Switch (Can't be controlled Manually)

If user turns manual switch then operation should start. (In this case, if someone activates automatic switch it should do nothing!) May be add an Normally close block here?
And if automatic switch is active then this case manual switch interlock should be actived to avoid any malfunction in the overall circuit.

I tried to add some NO and NC blocks in the circuit but can not justify the overall design as the two wires (+2) and (+3) will be activated at some point. Can anyone please help me with this? Can I use specific relays or NO/NC contact blocks to design this?

Please see attached picture for circuit diagram. Unfortunately, I can not change the most of the wiring diagram as it's fixed at this point. Please advise.

Thank you in advance,
Maitrey Pandya
Hi Maitrey,

Here's the interlocking concept.

untitled5.JPG

Only one power supply is required.

'M' refers to Manual and 'A' to Auto.

S1 is a single pole, 3 way selector switch for 'Manual', 'Off' & 'Auto' functions.

Manual relay (M), Auto relay (A) and Control relay for one operation (K1) are shown and may be extended. Control logic required by you may be incorporated in the vertical dotted line area.

-Nandu.
 
Last edited:

Tonyr1084

Joined Sep 24, 2015
6,455
If that's the control you want - great. Glad to help. If not - oh well; I tried.

Stay healthy. ")

[edit] Looking at it - you can do away with the first (left side) relay and change the manual switch to a SPDT switch. IF your remote has the same capabilities you can do away with all the relays.
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Note: In this configuration it's possible one or both relays may be on for a prolonged period of time. They need to be properly rated in order to not overheat and possibly fail. Also, the switch contacts must be rated to handle the load. [edit] Corrected errors. SW1 = Manual SW2 = Remote
View attachment 203172View attachment 203173
There is an issue in the above circuit. It will work for (1) and (3) case but not for (2). The reason is when we turn ON the remote switch it is not getting any power as Manual switch is OFF. Also the power which is connected to (C) of first relay has to be coming from manual switch nad not for additional source.
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Can't you just use the power going to the manual switch for the source?
I can not because, that power is coming from E-Stop NC contact and always active. If I connect my (c) there then I can only turn ON operation not OFF because 24V is always present there which will energize the whole circuit and will continue to operate.
 

Reloadron

Joined Jan 15, 2015
6,206
Sorry, I napped out a little and Tony, thank you. Post #17 is close and would work but I don't see why one relay uses high side switching and the other low side switching?

Make it like this or whet Tony posted.

Auto Man Off 1.png

Ron
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Sorry, I napped out a little and Tony, thank you. Post #17 is close and would work but I don't see why one relay uses high side switching and the other low side switching?

Make it like this or whet Tony posted.

View attachment 203182

Ron
Ron,

I am stuck with the actual connections though. I get the logic behind it. Any canges I can make to the following circuit to make it work?

The tricky part here is to implement when both SW is ON at the same time --- LAMP must be OFF.
1585773945807.png
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Nice catch, but still an issue as
You were closer in post #23. Tie the NO of the second set of contacts on RLY2 to the same contact on RLY1. It should work as desired then.
Nice catch but still an issue, as there is no power from the first switch thus won't work.
 

djsfantasi

Joined Apr 11, 2010
7,919
Sorry, you’ve posted so many different circuits that work for one feature and don’t work for another, I missed that.

Go back, review the circuits you’ve posted and look for the one that switches power for the relays and performs the lockout action you desire.

DON’T CHANGE ANYTHING ON THE SECOND SET OF CONTACTS ON BOTH RELAYS.
 

djsfantasi

Joined Apr 11, 2010
7,919
Sorry, you’ve posted so many different circuits that work for one feature and don’t work for another, I missed that.

Go back, review the circuits you’ve posted and look for the one that switches power for the relays and performs the lockout action you desire.

DON’T CHANGE ANYTHING ON THE SECOND SET OF CONTACTS ON BOTH RELAYS.
I looked back like I asked you to. Post #17 had the first set of contacts wired to lockout the other switch when the opposite switch is activated.

Combine the wiring of the first set of contacts per post #17 with the wiring in posts #23 and #33.
 

Thread Starter

maitrey

Joined Sep 4, 2014
75
Sorry, you’ve posted so many different circuits that work for one feature and don’t work for another, I missed that.

Go back, review the circuits you’ve posted and look for the one that switches power for the relays and performs the lockout action you desire.

DON’T CHANGE ANYTHING ON THE SECOND SET OF CONTACTS ON BOTH RELAYS.
Thanks Ron,

The problem is to connect 24 VDC to Lamps as If I connect it from first relay, it won't work for second relay and vice versa. Spent too much time on this ;(
1585777881280.png
 

Reloadron

Joined Jan 15, 2015
6,206
Not sure what you are looking for with the lamps but if RY1 is about temp controller 1 place the lamp across the relay 1 coil, place the second lamp across RY2 coil. Then each lamp will illuminate when its respective relay is energized. I don't have the software you are making your schematics with or I would have used it. Not sure what CW inlet is about?

Ron
 
Top