Lift Pump Control Circuit

[mmaxwell]

I'm an ME looking for some EE help. In need of a motor starter control circuit for a lift pump. Pump motor is 400V 3 phase about 1 HP. Yes, 400V. Control circuit is 24VDC. Transformer required. Inductive 24V sensor detects fluid and the pump comes on and runs continuously until the sensor detects no fluid and an programmable timer expires. The timer starts when no fluid is detected and the pump continues to run until the time expires. The timer resets when fluid is detected and starts again when no fluid is detected. The pump can run dry, I just don't want it to run through downtime. There will also be a high level sensor that opens a set of contacts for connection to a machine e-stop circuit. Pump continues to run in this condition. Selector switch for HAND-OFF-AUTO. HAND turns pump on regardless of sensor input. GREEN ready light in AUTO, YELLOW light in HAND, RED light in OFF. A set of normally open contacts that closes when the pump is in HAND or AUTO. No disconnect required as there is a receptacle to plug into on the machine. Basic low cost solution sought as I need to produce 15 of these.

 

[itsmoked]

Classic use for a PLC. There are some pretty cheap ones. If you need a useful user interface you want a PLC that's a bit above the cheapest variety. The cheapest variety are often called 'smart' relays.

Keith Cress
kcress -

http://www.flaminsystems.com