Electromechanical relay, 1000V 400A, aux contact rating

Support Q&A
1

------Question for AES400-CA Please Put your question below------

DigiKey PN: 2040-AES400-CA-ND

Question: regarding the aux contact.

  1. Is it configured as NO ie: same state as main contacts?
  2. This aux will be monitored by a PLC. Is it suitable as a reliable PLC input? The old electronic contact standard was DIN19240, not sure what that has been replace with.
2

The aux contacts are also NO and move along with the main contacts, both open or both closed depending on whether the coil is energized. But it’s not necessarily the same as the main contacts, they’re 1 Form X (double make switching action), while the auxiliary contacts are 1 Form A (typical single pole switching action).

As far as using it as a PLC input I don’t believe I could speak to that right off the bat, but it looks like one of our engineers is already in the thread, so I’ll let him say his piece on that front.

3

Form X is basically Form A on steroids for dealing with unfriendly use cases.

The ratings for the aux contact are 8V and 100ma minimum, suggesting that a small amount of arcing is required to clean off corrosion and assure continuity. Gold-plated contacts of the sort used for switching flea-powered logic signals that don’t draw an arc typically max out at about 0.4VA (gold doesn’t tarnish, but also doesn’t tolerate arcing…) so the character of the input in question would be relevant from that standpoint.

Beyond that, it’d be up to you to determine which (if any) standards apply to your particular use case and whether or not the device in question is in accordance therewith.

4

Many thanks.

Re: PLC input: to avoid any confusion, the only part of the standard that is relevant to this enquiry is the “low-energy, high-reliability” requirements. We don’t need to know about the mechanical integrity of the aux “positively guided”).

Google tells me that SIN 19240 was replaced with IEC 60947-5-1. I don’t have a copy of this.

For this product, can you advise what standard the NO aux contact complies with in terms of “low-energy, high-reliability” applications? I’d be surprised if this isn’t availabl - I don’t think I would be the only person interested in monitoring the NO aux of an electromagnetic relay via a PLC.

Thanks in advance.

5

Lacking ready access to the referenced standards myself, I’m not in a position to comment as to whether the device in question fulfills the prescriptions thereof.