Which Type of Limit Switch

[Clive S]

Ray This is why I posted

Just a thought although all of the above is correct are we assuming that the sensor has a resistor built in of say about 10K If not would it be prudent to put a current limiting R in.. My sensors have 10K internal so not needed.

It truly is not that difficult just buy the switches and play with one of them not connected to the BOB and see it working. You need to mount them as has been said so that the target slides across the top and not head on so to speak. ..Clive

[EddyCurrent]

Ray,
I got these from your earlier threads;



It looks like your power supply is this one;
http://www.zappautomation.co.uk/elec...-supply-7.html

You are using the 36v to power the steppers and the 5v to power the breakout board, you also have a 24v supply in there for the Pilz ?
Because the 36v is used for the steppers I would suggest not using that for the proximity switches as it could contain a lot of electrical noise, instead I would use the 24v supply provided it is DC and not AC.

Also, off topic, have you cut any of those nuts yet ? what tooling do you intend to use for a 9 gauge string slot ?

[cropwell]

This is maybe a daft question, but do not see a 24v supply for the PILZ unless it is that box to the left of it on the DIN rail.
.
What do these safety relays do that makes them cost £360? I can see a 4 pole contactor, which is presumably 3 phases and aux and I also presume there is some sort of RCCB and E-stop interface. If you are not running 3-phase, then it seems an overkill ('scuse the ironic pun).
.
An RCCB a break switch and NVR switch in series, would seem all that is needed for a good level of safety on single phase 240v.

[Clive S]

This is maybe a daft question, but do not see a 24v supply for the PILZ unless it is that box to the left of it on the DIN rail.
.
What do these safety relays do that makes them cost £360? I can see a 4 pole contactor, which is presumably 3 phases and aux and I also presume there is some sort of RCCB and E-stop interface. If you are not running 3-phase, then it seems an overkill ('scuse the ironic pun).
.
An RCCB a break switch and NVR switch in series, would seem all that is needed for a good level of safety on single phase 240v.

I must be going blind as I don't see a 4 pole contactor the schematic is showing 240V I have picked up those pilz for less than £10 on ebay. ..Clive

[JAZZCNC]

What do these safety relays do that makes them cost £360?

They empty your wallet sharpish. .. Lol

The Narrow white box next to Pilz relay is a 24V Balluf PSU. There is no Contacter in there that I can see.?

[manofgresley]

Yes it is a 24 volt Transformer, i fitted the Pilz on good advice off this site, cost £36.00. Ray

This is maybe a daft question, but do not see a 24v supply for the PILZ unless it is that box to the left of it on the DIN rail.
.
What do these safety relays do that makes them cost £360? I can see a 4 pole contactor, which is presumably 3 phases and aux and I also presume there is some sort of RCCB and E-stop interface. If you are not running 3-phase, then it seems an overkill ('scuse the ironic pun).
.
An RCCB a break switch and NVR switch in series, would seem all that is needed for a good level of safety on single phase 240v.

[manofgresley]

Now sorted, Many thanks, once again to all who have helped me with there advice and wisdom.

Ray

[cropwell]

The contactor I was referring to seems to be built into the safety relay. Then there is also an e-stop input and presumably other safety measures built in. I looked at the PILZ website for some information, but just got boggled with detail. They quote £360 for the PNOZ. I'd want it in gold for that money !

[EddyCurrent]

The contactor I was referring to seems to be built into the safety relay. Then there is also an e-stop input and presumably other safety measures built in. I looked at the PILZ website for some information, but just got boggled with detail. They quote £360 for the PNOZ. I'd want it in gold for that money !

They are designed for industrial use, nobody like us pays full price, here's one for example £25;

http://www.ebay.co.uk/itm/PILZ-safet...item2ed3f7fc61

[cropwell]

I understand the pricing policy. If you are selling to a large industry customer you have to provide support and have product liability. They have to be at such a price that they can just swap out any problematic unit. Also the employer has to have employee liability and that would probably preclude buying from an 'unreliable ' source.

I wouldn't mind if anyone could tell me the modular functionality of such a unit, and what qualifies it to have the title 'safety relay'.

I'll probably include one in my next build.