Machine safety - contactors

Hi,

I'm reading up on the ISO 13849-1 and have downloaded Sistema to evaluate the safety circuits and develop my skills. I have a question about the contactors.

In most machines I see they use regular non-safety contactors.

According to Sistema when I choose "typical components value" (good engineering practise method". They state that a contactor with nominal load is 1 300 000 B10D. When I choose a safety contactor from Rockwell it gives me 1 333 00.

However when I select a standard contactor from Rockwell in the Library I downloaded from them it says:

"This product is not specifically intended as a safety device and the given data represents reliability data. Any use of the terms MTTFd, B10d, T10d or PFHd does not relate to a failure to danger. The user assumes all costs and liability for any decision to use these products as part of a functional safety related system and on what represents a failure danger."


So, with that conclusion I would say that to use a normal contactor in safety circuits is not allowed (atleast from Rockwell but I suspect other brands to have the same condition). But in the standard it says that if I have no data of the component I can use 10 yeas as MTTFd. This is only allowed in Category B, hance PLa.

It is a little bit conflicting, but I suspect that the manufacturers instructions overrule the 10 year MTTFd so that I can't use a standard contactor in safety circuits anyway?

/Tim

google: schneider LC1D09 datasheet.


You'll see the B10d for this contactor.



Also the fact that is uses mirror-contact used in the feedback-circuit.

A normal contactor is allowed. The contactor must have force guided contacts (all typical contactors have that, all typical relays do not have that, except for safety relays).

I think that the text from Rockwell is legal-speak that tries to clear Rockwell from any liability. But I dont think that they can actually free themselves from any liability by just stating such a text. If they could, it would mean you cannot use Rockwell contactors in safety applications.

Question to US members:
Do you use Rockwell contactors as part of a safety system ?
If you do, what do you think about the statement that rQx posted ?

Rockwell contactors are some of the only ones unless safety rated, that do not have the required separation and linking of poles to meet criteria in the safety regulations.

A normal Siemens contactor, for an example would.

Any use of the terms MTTFd, B10d, T10d or PFHd does not relate to a failure to danger

Click to expand...

The "d" in all these terms means "danger". So they should simply not state any of these if the contactor is not to be used for a safety system.

Contactors

Rob... said:

Rockwell contactors are some of the only ones unless safety rated, that do not have the required separation and linking of poles to meet criteria in the safety regulations.

A normal Siemens contactor, for an example would.

Click to expand...

Rob, just asking for clarification: Rockwell (among some others) are NOT suitable unless safety rated, but Siemens (and many others) ARE suitable, even if not safety rated?

RoTaTech said:

Rob, just asking for clarification: Rockwell (among some others) are NOT suitable unless safety rated, but Siemens (and many others) ARE suitable, even if not safety rated?

Click to expand...

For an example, siemens 3RT range, already comply with all EN standards to be safety rated. They just don't sing and dance about it like Rockwell do.

After speaking to someone at rockwell the only reason their standard ones don't comply is due to a mistake at the design stage. However marketing swung it pretty nicely and generated a new product for them.

The contactors for use in safety circuits need to have the contacts linked mechanically, as IEC 60947-5-1 specifies.
Many of the standard Telemecanique contactors comply with that. I do not know about other brands.

The standard one ( 100-c for me ) is stated to comply with 60947-5-1.

The main thing is that in Sistema Rockwell state that it shouldnt be used, so what happens if we do and something goes wrong. Who is responsible? I guess that it will be me.

We use the standard ones and can ofcoarse change but the safety contactors dont match the standard ones in voltage and size, meaning a rebuild of our panels.

I have also noticed that when siemens make a safety funcion example they use for example a standard 3RT but Rockwell ues their safety contactors. I just thought that Rockwell wanted to sell me something overpriced and fancy

Tesys D contactors can be used in safety circuit since they have mirror contacts.

https://www.schneider-electric.co.uk/en/faqs/FA136111/

kallileo said:

Tesys D contactors can be used in safety circuit since they have mirror contacts.

https://www.schneider-electric.co.uk/en/faqs/FA136111/

Click to expand...

In that FAQ schneider stated that contactor used in safety should have mirror contacts in acc. to 60947-4-1. The Rockwell 100-c serier conform to both 60947-4-1 and 60947-5-1

What about the rockwell 700S-CF series?
They have force guided contacts.

bill4807 said:

What about the rockwell 700S-CF series?
They have force guided contacts.

Click to expand...

Yes, but we need the equivalent of the 100-c55ej00 contactor wich is a 55Amp contactor with electronic coil.

rQx,
This is the closest A-B gets:
100S-C55EJ22C

They don't have one without auxiliary contacts.
I've never used one this big, but the size on the smaller ones aren't much different than the standard contactors.

Picklemon said:

rQx,
This is the closest A-B gets:
100S-C55EJ22C

They don't have one without auxiliary contacts.
I've never used one this big, but the size on the smaller ones aren't much different than the standard contactors.

Click to expand...

Hi,
I can't find this one on ABs site. They only have up to c43. Are you sure they make this one?
/Tim