DoL with pilz relay

[Cook_90]

Hey all, fairly new to this so bare with me,
i have an interview this week and Iam expecting a skills test does anyone have any idea what I could be facing? Or what you have experienced, the job is in a food processing factory.
ive heard rumours of having the wire a dol with pilz relay?
not worked with the pilz before so any help would be great

thanks

 

[Spoon]

Pilz are known for their Safety Relays, so could be used for guarding in the food factory. Don't know about using one for a DOL starter.

 

[Spoon]

Just found this. It might help you out.
http://www.electriciansforums.co.uk/electrical-forum-general-electrical-forum/92278-pilz.html

 

[Cook_90]

Thanks guys, so how would I intergrate this into a dol? And the benefits etc?

 

[Spoon]

Hi Cook, I'm not quite sure what you are after. Are you suggesting using a Pilz relay to detect a guard on a food mixer that switches off the DOL if the guard is open.... or something like this.
First of all you would have to do a Risk Assessment on the food mixer.

 

[Cook_90]

Hi Cook, I'm not quite sure what you are after. Are you suggesting using a Pilz relay to detect a guard on a food mixer that switches off the DOL if the guard is open.... or something like this.
First of all you would have to do a Risk Assessment on the food mixer.

Yeh something like that, a standard dol driving something like a conveyor belt with several emergency stops at different locations, using the pilz to monitor the e-stops?
would I just use the pilz as a series of n/c n/o contacts which would be switched via voltage onto the pilz coil? If that's how pilz are used?

 

[Darkwood]

Safety relays can operate in several ways and the one you pick or require is subject to the safety catagory of a risk assessment.

The very basic one can still be wired to operate a few different ways, you can commonly get 1 and 2 channel which means its monitoring 1 or 2 channels and the latter usually requires both to operate together, if there is any differential between channel 1 and 2 on opening of the monitoring circuit then the unit will not allow reset and may need to be powered down to reset it.. this has the advantage of having a higher level of fail safe on the monitoring circuit.

A simple example would be a 1 channel unit where the E-stops interupts the power supply to the unit, thus dropping out any circuits you run through the unit... fitting and removing links gives choices like manual reset (a requirement in most cases to have a seperate reset action). Most units are powered constant with some have internally powered monitoring circuits which have there pro's and cons others common voltage monitoring circuits, what I'm getting at is even the basic unit comes in many varieties and can get quite complex very quickly if you are new to them.

 

[shanky887614]

a very basic circuit would be relay powering the dol with n/c contact then any stop etc pushed will shut it down.

 

[Darkwood]

http://www.ibb-boehm.de/media/uploadpdf/935-PNOZ_X2P_GB.pdf

Look down the page and you get the options for E-stop, gates etc and the various connection arrangements and the required unit that will give these options, these will suffice for up to cat4 requirement depending which method you choose.

Note!.. this is one brand and other brands will differ, plus this is a basic wiring arrangement, like I said they can get very complex and very expensive to boot as you can assign different funtional outputs, time delayed etc etc to the more advanced units.