Emergency stop circuit

Sillver

Member
Join Date
Feb 2010
Location
us
Posts
7
Hi,
My company uses Schmersal SRB-C.46 relays in an emergency stop circuit. The relay has 3 NO outputs and 1 NC output for monitoring. When the power is connected to the relay – will the NO contacts close and the NC open? Or is it the emergency input alone that triggers this? Cant really make sense of the NO / NC part of the drawings. The drawing shows the NO contacts as open – but when everything is running as normal these contacts will have to be closed or?

E-stop is connected to S12 – S11. When this signal changes state – K1 and K2 will also change state right?

http://www.schmersalusa.com/installation-details-pdfs/SRB-C_46.pdf

Thanks!
 
Hi,
My company uses Schmersal SRB-C.46 relays in an emergency stop circuit. The relay has 3 NO outputs and 1 NC output for monitoring. When the power is connected to the relay – will the NO contacts close and the NC open? Or is it the emergency input alone that triggers this? Cant really make sense of the NO / NC part of the drawings. The drawing shows the NO contacts as open – but when everything is running as normal these contacts will have to be closed or?

E-stop is connected to S12 – S11. When this signal changes state – K1 and K2 will also change state right?

http://www.schmersalusa.com/installation-details-pdfs/SRB-C_46.pdf

Thanks!

For the E-stop, the unactivated position is with the E-stop pushed in. This is the default, that is shown on the figure of the relay (this would also be the condition of the relay when there is no power to it).

-Brian
 
the relais will be off until reset input has been on.
depending what circuit is used NO (10)or NC (20)the relais will be switched off again when contact is changed.
 
Sillver,

Both of the two previous answers are correct, but I want to try to make it a bit more clear.

"N.O." and "N.C." refer to the state of the contact when de-engergized or, another way to think of it would be "as you take it out of the box". So, when no power is applied OR the E-stop circuit is not satisfied (E-stop condition detected or not reset), a N.O. contact will be open - not passing current - and a N.C. contact closed - passing current.

K1 and K2 are the coils inside the safety relay that drive these contacts. When the E-stop circuit is satisfied and the relay has been reset, these coils will energize and change the state of the contacts.

Hope this helps.

Steve
 
Steve Etter has it exactly. Wiring diagrams and documentation for relays will show the contacts in the de-energized or "shelf state".
 

Similar Topics

I'm working on a project that has e-stop pull cords around the full length of a conveyor system which is about 750 feet long and it has 16 e-stop...
Replies
16
Views
7,893
Hello everyone. This is my first time designing a system from scratch. The system is for a rubber injection molding press. I have the PLC all put...
Replies
35
Views
11,231
I have a project that I'm doing the automation for and wanted to throw my scenario out there to see if anyone could offer some advice/suggestions...
Replies
17
Views
7,443
Hello, I have plc Schneider TM241CE40T with the hmi HMIS5T. Do you have idea how to disable a button after an emergency stop to vijeo designer ...
Replies
5
Views
1,379
Dear colleagues I am learning to program siemens plc. I have a problem with how to solve the problem with a power outage and emergency STOP...
Replies
3
Views
1,674
Back
Top Bottom