"First Up" Hard Wired Circuit

Have the C1 relais controlled by your 4 relais.
so one contact of the four in series. (this will stop the turbine)
every contact goes to one relais simple parallel.
now you can see which contact will fail as one relais will stop activated. the one relais that stops has three contacts to keep the power on the other ones.
It means 4 DT contacts (industry standard)

rootboy said:

I've gotta agree with Cheezy, when you lose Switch1 you lose all of your relays. Then it just becomes a relay race to see which one latches in first.

It's one thing to test it out on a sim, it's another to have to deal with the built-in latency of a mechanical relay.

Click to expand...

Wouldn't it be any switch that drops out for that matter. I mean it seems it should have the same affect.

inst_tech said:

Hello,

Was wondering if anyone could improve on my "first up" circuit. I'm sure there is a way but cant quite get it!

What I've got is 4 switches pulling in a contactor. I wish to find which switch drops out first. I've done a program in statment list but was trying to do it hard wired as well.

The attachment shows what I have. First cicuit is the original. The rest is the wiring I need to capture the switch dropping out.

Is it possible to do it with just 4 relays rather than 8? I must be missing something!


cheers

Click to expand...

Actually if you go strictly by your circuit, then all you have to do is see which of the 4 relays is no longer energized. That is the one that will be the culprit.

As an example, if relays 3 and 4 are off, then switch 3 is what went. If 2, 3, and 4 are off, then it was switch 2.

What I've done in the past is to use latching relays (like bce123 suggested) in place of R1, R2, R3, and R4. Arm the relays so they indicate latched. Then the first relay that is unlatched is the switch that caused the problem.


Now, if the circuit is not exactly like you shown and the entire circuit drops out if any of them open, then just looking at the energized relays won't work.