Understanding a complicated looking relay

Question

When I think of a relay this is what I imagine

schematic

^{simulate this circuit – Schematic created using CircuitLab}

not this

Can someone please explain how this relay works and how it should be wired to produced the standard behavior of a relay. ie. send current through the coil and the switch closes.

Thanks

That thing looks like a module that belongs as part of a furnace or something. You will probably have to disclose where you found that thing. — jonk, Mar 09 '18 at 04:01
It's a standalone parts my work someone at my work bought from automation direct [link](https://www.automationdirect.com/adc/Shopping/Catalog/Safety/Safety_Relay_Modules/E-Stop_-z-_Safety_Gate_Relays_(1_-_Channel)/LG5924-02-61-24) Its being used as a part of a big electrical setup. — user2757771, Mar 09 '18 at 04:07
it looks like you connect A1, and A2 to a power source, and then connect Y1 to Y2 to activate the relay. — Jasen Слава Україні, Mar 09 '18 at 04:21
It's a safety relay. See my answer to [this question](https://electronics.stackexchange.com/questions/240280/symbol-or-marking-on-safety-relay/240352#240352) and [this one](https://electronics.stackexchange.com/questions/244088/self-checking-circuit/244111#244111) for an introduction. — Transistor, Mar 09 '18 at 07:43

score 6 · Answer 1 · answered Mar 09 '18 at 05:05

The link to the distributor's website had a spec sheet

In it is a diagram of how the relay is to be used.

A1 / A2 are 24Vdc power connections and Y1 / Y2 is a restart input (which can be jumpered). Normally, this input would be used to require a restart button to be pressed before engaging the relay.

K1 / K2 are monitored contacts in series. In safety applications, if one set of contacts were to weld closed when attempting to open, the other would still open. The relay would subsequently not close the contact again as it monitors the position of both sets of contacts. See force guided contacts for more.

score 0 · Answer 2 · answered Mar 09 '18 at 04:26

From a quick look at the timing diagram in your linked spec, it is intended for large machines where actuators put the operator at risk unless both hands are out of harm's way. The operator must used two hands to turn ON and both released to turn reverse. In Logic terms it means both high then both low activate the two relay states.

I remember seeing these types of controls for stamping machines with 10 ton presses where the operator replaces the sheet metal after each operation. circa '75

Understanding a complicated looking relay

2 Answers2