Suggestions for easy-to-program time switch

We have a cooling system that has to be flushed on some as-yet-unknown schedule. Flushing consists of just opening a solenoid valve for two minutes. It could be several times a day, or just once a day, or maybe a few times per week--we won't have a better idea until we have the system in place. I'm looking for some type of digital time switch that would allow all of these different scenarios to be configured, and be easy to program since we don't know who will be doing it.

The problem is that all of the time switches I'm finding with this level of adjustability are very unintuitive and cryptic to set up... i.e. a small number of buttons where each button has multiple functions, holding in the button has yet another function, yada yada we've all been there. (Example is Omron H5L.)

Does anyone have any suggestions? I'm envisioning something with a large LCD screen that is either touch-controlled or has a decent number of buttons that make sense. Unfortunately I can't justify the time required to come up with a PLC+HMI solution for this--I'm hoping to find something off-the-shelf.

My thought is a Time Clock Buzzer control like this.

Can be programmed for multiple On's per day, set a weekly schedule.

If the buzzer time can not be set long enough have it trip a standard timer set to a OneShot pulse for the run time.

is Theben brand (TR612) sold there?

A programmable relay might be a good fit.

Ken Moore said:

A programmable relay might be a good fit.

Click to expand...

How do you figure? I know there are smart relays available with built-in clocks, but wouldn't you have to modify the program logic to change the on/off times? I'm not aware of any with an interface that a layperson could use.

I used a timing relay from Omega once for a similar situation except I need to operate 3 different valves each on their own time schedule. It was a pain to figure out how to initially set up the thing, but once I had that sorted out, the operator could adjust the time intervals relatively easily with buttons and LED readout.

I think it was this one:

https://www.omega.com/en-us/control...-and-timers/process-meters/ptc-15-16/p/PTC-16

After seeing the picture, I also recall not being a fan of the shoddy little screw terminals, but the little thing did the job in a spot where they didn't want or really need a full blown PLC/HMI. I seem to recall having to wire one output back to an input to re-trigger it...It has been quite a few years ago. It took me all day to get it to do what I wanted on the bench mainly because of the poorly written instructions.

kolyur said:

How do you figure? I know there are smart relays available with built-in clocks, but wouldn't you have to modify the program logic to change the on/off times? I'm not aware of any with an interface that a layperson could use.

Click to expand...

AB 810 w/lcd

You can also use the LCD on an old 1100/1400 Micrologix to change timer settings. It takes some programming upfront but it works pretty solid.