Start, Stop, Jog !

[Bacon]

You could allways go for a 2 hand inch operation circuit with a timer,

Which upon release times out before inch circuit can be operated again

We used to do this on our forging presses which was for the prevention of an operator having a hand in the presse while inching it over.

 

[Evans Electric]

Not a bad idea Bacon ,  I made up a two handed jogging button for a printer's Folder/Stitcher M/c  .  Used an overhead crane pendant control station with each button at the furthest ends so two hands had to be used and as you say , no fingers in the machine . 

 

[Evans Electric]

Thanks for that Canoey , I don't do much industrial work these days and what knowledge I have was accrued , as you said, "in the old days" .   My first customers , Boulton, Watt and Murdock ,   along with Archdale & Alfred Herbert  were quite pleased with my services.   :innocent I bow to your superior knowledge :Salute

 

[Bacon]

We used to use pilz safety relays i think.

 

[steptoe]

Thanks for that Canoey , I don't do much industrial work these days and what knowledge I have was accrued , as you said, "in the old days" .   My first customers , Boulton, Watt and Murdock ,   along with Archdale & Alfred Herbert  were quite pleased with my services.   :innocent I bow to your superior knowledge :Salute

thast automated stable door you fitted for me still works fine Deke,

though I do find it tiresome having to shovel all the coal to get the steam up sort of negates the effect of just simply pushing the door myself.

 

[ProDave]

If you are really concerned about malfunction of the "model" start, stop, jog circuit, then why not design your own.

Rather than having two completely separate contactors, I would have one contactor and one relay.

the contactor would switch the motor, whichever button was pressed, and the relay would be used for the hold on function, independent of the contactor. and the relay would only get energised by the start button, not the jog button.

 

[Sidewinder]

You still have to comply with the current requirements for machine safety circuits, and, a single contactor control does not meet this any-more!

As the Boaty one says,

You are looking at dual channel safety relays (AKA Pilz, others are available) amongst other standards & requirements.

BS7671 is not even considered in such a scenario TBH,

 

[apprentice87]

Hi Paul, Are you saying that it would be the best plan to use to separate contactors for each function like i thought of doing in the first place?? I suppose then if i wanted an emergency stop, i could just wire this so it cut the feed to BOTH contactor coils..??

john