Re: why the relay chatters & gives the output to the PLC CPU input & whole machine st
If measured voltage from LA to N is 220Vac and measured voltage from J to N is > 220Vac - 5%
there is no problem at that time.
But if measured voltage from J to N is < 220Vac - 10% there is problem in some switch , some cable or some screw connector.
Then you must find out by measuring between which connector points the voltage drop occurs.
i.e. you must measure every point to point voltage.
Every closed switch and cable should have voltage drop very near 0 volts , if there is found some higher drop for ex. 5V , its clear failure.
This mean every switch and every wire between switches must be measured individually.
Another way to do that is measure LA-SB1a and SB1a-SB1b and SB1b-SB2a and SB2b-SB3a and so on, until to point J.
You gonna need one long wire for lenghten one measuring cable.
switches are closed means pressed ???
In circuit drawning serially connected switches to stop relay are normally closed type, i.e. switch is open when pushed.