e-stop master / slave circuit

Hi all

we have a production line that currently has 3 e-stop zones (very confusing for operators)we are changing it to 1 zone.

Each existing zone consists of 1 master(1 machine has a msr210P) and X ammount of slaves (in other machines). The e-stop buttons of all the machines in that zone are connected to the master and then a set of contacts from the master is connected to the slave.

what i propose to do is take 2 of the existing masters and make them slaves to the last remaining master, this would give me 1 overall master with 2 slaves, but these 2 slaves would be masters to all the other slaves, in effect givng me 3 levels of safety relays ie, 1 x master ( level 1), 2 x slaves/masters (level 2) and then X ammount of slaves (level 3).

could anyone tell me am i ok to do this, can you keep on repeating this or is there a maximumn number of levels you can have. I'm in dublin and would appreciate if anyone can point me in the right direction to the current regs etc.. I can't find any regulations that say i can't do this, but can't find any that say i can either.

cheers

sparky.

Hi sparky

I live and work in Ireland and I have done this and had no problems
getting it signed off.
The only thing is make sure it is dual channel and that all relays
master and slaves are reset from one blue push button in a central
location.The last time I did this we had about 14 different machines on the one line and we had to tie all them to one master relay.

Hope this helps

Donnchadh K.

Hi Donnchadh

thanks for the reply.

The system is dual channel, but i will have more than one reset, the worst case scenario is the production people will have to press 3 reset buttons, 1 for the overall master relay, 1 for the slave / master relay, and then 1 for the slave relay on the machine. I have all the messages including tag numbers on the relevant hmi's telling people where to go to press the reset buttons, as long as this is within the regulations i'll keep to the existing buttons, or do the regs say i have to 1 reset button??

do you have any links to documentation i can read through.

sparky

Hi Sparky

If the line has to be CE marked you can only have one BLUE reset button to reset a line e-stop.
The saftey regs allow a number of reset buttons.I will be in the office tomorrow after dinner and will have a look for something on paper.If you are in Dublin and need anything else just drop me a private mail and you can ring me if you are stuck for anything as I am in Dublin later in the week.

Talk soon

Donnchadh K.

Hi Donnchadh

If you've got something on paper regarding the CE marking i'd appreciate it, because we will be looking at doing the CE marking.

If i have to, i will change the system to one blue reset button instead of the 3 existing buttons.

sparky

Hi Sparky

I will get back to you tomorrow when I am in the office.

Donnchadh K