Hello,

Has anyone had any experience with click plc's? I got a small one to moniter some support equipment. If there is a problem it sets off a strobe. I am using relay outputs, so I understand they can stick after a while, but after installing everything I was testing the system and on the fourth or fifth time my strobe went off the output stuck on. I am using 120v for voltage, is there anything I can do to make this not happen? Or did I just buy a cheap PLC and I am getting what I paid for?

Thanks much,

plcdp

How much current did your output device draw and is it inductive? By 'stuck on' do you mean that the relay contact welded? Or did the logic just keep the output on?

It is not just the current, but the "inductiveness" of the load.
What do you mean by "strobe" ?
Is it some kind of flashing alarm beacon ?
If that is so, there is probably a small electronics unit with power supply, large capacitors and coils. And that makes an inductive load.

Use a contactor and/or combine with a surge suppressor.

The strobe draws .7 amps. As far as it being inductive, I don't know what you mean. I am using a Tomar microstrobe p/n 495s-120a. On the website it says: The power supply is a high efficiency solid state power supply, and it also states that it has a built in filter to protect against power spikes. If that tells you it is inductive or not I don't know.

And yes the contact welded, not a logic problem.

Thanks

Sorry, the amperage draw is .07 amps not .7

Their documentation shows .07 ams AVERAGE. The installation shows a 3 AMP fuse. I suspect there are some pretty good surges going on.

So even though they have a built in surge suppressor I need another one?

Or would it make more sense to use a relay of some sort? I think that is what JesperMP meant by a contactor?

use power relay or contactor to drive this load. this thing discharges 2.3J per flash. that means huge current - although for a short moment. due to very low duty cycle, average current is low (70mA) but the pulse current is way bigger.

It is a VERY inductive load.
The integral electronics has a PSU (=transformer coils and capacitors), and then it also has a filter (=even more coils and capacitors).
The PSU takes care of storing the energy for release in the strobe, so it is not the high current, it is the induction.

Use a contactor, and ALSO use a surge suppressor (varistor or RC) over the supply terminals to the strobe.

Thanks to everyone for the help. It is greatly appreciated.

plcdp

Edit: One last thing... I have some solid state relays in stock here that we don't use anymore. Could I use one of those?