I think we need a refresher; some of the above information is incomplete.
Floats on rods? How quaint. The most common arrangement uses simple floats on cords, tied off to a pipe.
If there's but one pump, and one float, the float has a 'piggyback' plug, and your delay between 'on' and 'off' is built into the float.
The delay prevents short-cycling of the pump. Typically, the float will be pointing noticeably 'up' before the contacts inside close, and pointing noticeable 'down' before the contacts open again. This gives you perhaps a 4" difference between the 'on' and 'off' water levels.
For duplex pumps, you have a single circuit supplying the control panel. The control panel, in turn, feeds the pumps.
Your lowest float doesn't seem, at first glance, to do anything. Yet, if it doesn't close, neither pump will work. It serves to shut everything 'off' after the sump has been pumped down.
The next float turns on the first pump. An alternating relay in the panel will make the pumps take turns being 'lead' pump.
The third float - usually also the top float- will turn on the second pump and sound the alarm.
If there's a fourth float, it's the top float, and it only sounds the alarm. In this set-up, the third float only operates the second pump.
Now ... commercial plug time ... I've seen a variety of pump panels. One place seemed good, until I called them for a replacement part, and only silliness followed.
A surprising number of the panels I've seen, under various names, have come from SJE-Rhombus. You can buy direct, and their customer service is top-notch.
That is what they are Reno, cord floats. There is no schematic or info on control panel in first building. I think what you are saying makes sense. I checked voltage at T strip and two floats seem to work in tandem. So if I am interpreting you correctly, 1st float closes than second float starts pump, and they alternate with the alt relay. That seems correct. Third float should turn on alarm and make both pumps run simultaneously? Okay, I did not check third float because I was told it was for alarm and the alarm is broken. This sump is very large so I never was able to fill up with hose. Would of taken hours and also would have had to pull up second float to allow water level to get up high enough. I guess I could of lowered third float in hindsight to test. The head of maint. there ordered another panel (Dayton). When I go to install I am going to check on what you are saying. It makes sense. Four buildings and all sump panels are different. Also people who shouldn't be touching elec keep messing with these things. The co. who changed pumps in one building, installed two brand new 120v pumps, and hooked one up with both legs on the contactor(208) It ran, but was drawing 37amps!!! 1/4HP. Head of maint who keeps telling me he is a 'master electrician' swore up and down they had two 240v pumps, until I pulled them and showed him they were 115 1/4hp.
