Made a sewage pump controller to alternate two ejection pumps

Looks like you found a good solution to a shitty deal (pun intended)

"Ignoramus13687" wrote in message news:YKOdnU5IxMcqqhLOnZ2dnUVZ snipped-for-privacy@giganews.com...

What does it do if a pump fails or the breaker trips anyway? jsw

It was very shitty and extremely frustrating.

If the breaker trips, everything stops. If a pump fails, depends on what pump fails. If The forward pump fails, the rear will run constantly. (as it would without this controller).

If the rear fails, the forward pump will work fine, but the system would not be useful.

I hasten to add, that the controller runs them according to a certain logic, made to ensure optimum pumping. Described on the above webpage.

I asked after trying to think of a cheap, simple and reliable way to indicate malfunctions using the float switches and motor current sensors. One would be to detect either float switch being closed for longer than perhaps 10 minutes, with a time delay relay powered from your breaker instead of the pumps'. jsw

This controller is located inside a sewage manhole away from everything, it is hard to make it signal anything.

The simplest approach is to use a current relay picked by the downstream pump running to prevent the upstream pump running (priority to downstream pump). I.e., the upstream pump can only run if the downstream pump is not running. The downstream pump can run whenever it needs to.

Your description of a relay for each pump implies that the downstream pump cannot start if the upstream one is running. What made you decide to do it like that?

Bob

This is exactly what I did.

And that is NOT what I id.

I have edited my description to be a little clearer, using terms upstream and downstream.

There are plenty of cheap wireless link modules available, even WiFi.

if you ever find a good one, let me know. I gave up on a low temp alarm for the greenhouse.

Karl

Why haven't you optimized it so a pump in your building pumps it into the city system, bypassing the dual septic system kludge? OK, a sludge kludge, guys, as long as we're punning here.

Because the city system is 300 yards away, behind two other properties and one railroad.

So what? It's getting there now, it's just kludged together. Why can't you bypass the two septic systems with pipe? Then you could use either pump to get yer shit together. Is there a limit to the head your pumps have to get the waste to higher ground, or something? And why is rainwater an issue? Something's broken in your system now, Ig. Can you pawn it off on other property owners or the City, or get their involvement to repair the system? Maybe if you do it, they'll pay for some of it.

"Ignoramus13687" wrote in message news:LK6dnY5olbYGVBLOnZ2dnUVZ snipped-for-privacy@giganews.com...

Please take this discussion as an interesting design exercise rather than a suggestion to rip out and redo what you have. It sounds like your consequences of failure aren't as bad as an overflow in someone's home.

I incorporated a 4-channel priority encoder into a dynamic RAM memory controller custom IC. It was more difficult to understand and fully specify the operation than to design the logic circuit to implement it. My boss forgot to ask for a buffer enable signal from the channel that had been granted priority so after all that work we couldn't use it. At least I could add ASIC design to my resume.

-jsw

Right.

What happens when the pumps fail, usually, is bad, but not catastrophic. Sewage somewhat rises in the system an I can see it rise in one of the floor drains, but it does not overflow into my building. Toilets become harder to flush. No sewage flood occurs, however.

This was nice.

From your description I could assume that the first, upstream pump runs independently and the second can start only if the first is off. Will the second pump shut off when the first one starts?

As an old ladder-logic designer I'm trying to see how few relays I could do this with. One mechanical relay controlled by the first pump's float switch would run the first pump through its NO contacts when energized and send power to the second pump through the NC contacts when off, but that doesn't work with SSRs and may not last long in 100% humidity plus ammonia from urine and cleaning compounds.

Of course a surplus dealer or hobbyist might modify the circuit to use whatever they already have instead of buying new parts for the most logically elegant solution.

-jsw