Fruit Trader

Have the water tested before firing the new parts cannon. Our well water used for product cleaning is manganese rich and clogs resin softeners over time.

Britney Spears with "Oops I did it again!" would have fitted quite well in 1939. World war leader board :- Europe 2 – US 0

Not being a native of the UK, that needed a lookup. Beat the clock with Swan brand (Bulpitt & Sons Ltd) = Save time and get things done faster using Swan appliances. Andrew James, Russell Hobbs, Swan Brand = Made in China Your new kettle has travelled approx. 20,000 kilometers

Russell Hobbs, the king of kettles.

Thanks for not painting it corporate grey, a trend that’s thankfully fading away.

Unlike traditional house pumps a true constant pressure pump will not cycle on and off around a pressure switch differential but instead keep a constant pressure using a speed controlled pump motor. There are pumps that attempt constant pressure without speed control and do this by monitoring flow and pressure to keep the pump running. Compact versions of Hitachi and Mitsubishi house pumps attempt constant flow without inverter speed control. A showers electronic temperature control would be working harder to keep temperature if its supply pressure is rising and falling to the tune of an automatic pump with pressure switch control. Its not a big problem just an example of how constant pressure can be an advantage.

Last word. If its a 3 wire sub pump don't forget the capacitor start when sharing the pump between controllers.

Your diagram enhanced. The diagram works if wired correctly. Its a simple relay circuit that shares a pump between M521 pump controller and EPC4 pump controller. Relay off, M521 controller is connected to the pump and will power the pump via its own relay when required. Relay on called by EPC4, the M521 controller is disconnected and pump gets direct feed. This will work but as I already mentioned in this thread and back in Aug 2025 the EPC4 might not shut off if its supply is also filling the tank.

First test with tank ball valve closed. 220V on the EPC4 check EPC4 output is connected to the pump directly - check open the tap connected to outlet of EPC4 pumps runs - check close the tap connected to EPC4 pump stops - check Conclusion, EPC4 works ok now introduce the relay and tank ball valve.

The test is simple. When the tank ball valve is open is there enough pressure from the pump to satisfy the EPC4 pressure switch.

Then you simply replace the pump with a 220V relay which is exactly the setup in my photo but in this case the relay is there to take the load off the EPC4 contacts.

Here is a photo of an EPC4 type controller sitting on a shallow well pump. Its output connects to an irrigation valve and timer. When the irrigation valve closes the EPC4 sees not flow full pressure and cuts off after a small delay.

If the tank ball valve is open there will be a pressure drop at the feed to EPC4 which will likely prevent it from turning off its output when outlet is closed. The idea of having a irrigation timer valve on the EPC4 is good providing the EPC4 can get enough pressure from the pump to activate its pressure switch. Normally an EPC4 type controller turns on a pump that feeds it alone.

In this situation the EPC4 would not shut off if the tanks ball valve was open. Normally you would not need a mechanical ball valve where a tank auto fills electrically. The best way to handle this is to put a normally closed 220V solenoid valve on the tank feed. EPC4 wiring is simple, mains in pump feed out. The EPC4 will fault if the conditions are not correct to energise its pump relay.

The diagram appears to show a pump is shared between EPC4 and M521 using relay changeover contacts. This suggests the tank fills via an open ended feed and the EPC4 water inlet is sharing the same line. How can pressure ever rise to stop the EPC4 if the line is always open to the tank? The EPC4 detects both flow and pressure to achieve constant pressure operation. It requires no flow and a rise in pressure to cut off which is done by its control logic. Correct me if wrong but I see the EPC4 calling a pump that will start filling a tank unless you have some device in line to stop this.