Posted 6/26/2020 06:48 (#8336771 - in reply to #8336542) Subject: RE: Raven 450 monitor
Southern Minnesota Between Freeborn & Wells
There are various types of control valves. It sounds like you have the very common type that has a butterfly valve to control the product flow. Some other systems control the speed of the pump.
The control valve is controlled by a green and yellow wire. The controller sends +12V on one wire and ground on the other to run the motor in the direction that will open the valve. It sends ground and +12 volts to run the motor in the opposite direction to close the valve. A good share of the time there is neither power nor ground on these wires to the valve stays at its current position.
This type of valve has limit switches on a circuit board below the motor. There are two. Their purpose is to "limit" the travel of the butterfly so that is goes from closed to about 80 degrees open. Without these limit switches the motor could continue to run in circles and once past the limit point would start to affect the flow in the opposite direction.
There can be a problem with the circuit board and its limit switches. This is especially common if the seal on the motor output shaft has leaked (froze during winter because it wasn't drained) which allowed liquid into the circuit board and caused corrosion. A circuit board repair kit used to be available but it is often just better to replace the complete control valve.
Obviously a problem with the green and yellow wires will be something to check as well.
The operation of this type of control valve is easily checked. If you connect it to a 12V battery, the motor should start and turn the butterfly unless it is already fully open or closed.. Reversing the wires should cause the motor to run in the opposite direction and then stop when that limit is reached. Reverse the wires and the motor should turn the opposite direction again. Try this a few times. It should take 8 seconds to go from one extreme to the other. If this seems reliable than the problem is elsewhere.