matt_s
New Member
Hello,
A little background:
I inherited a situation here in NC in which the above-ground portion of pipe will freeze at the well head. With the goal of installing some heat cable and pipe insulation, I want to provide a constant source of power for the heat cable. Unfortunately, there's no simple way to get an extra set of wires out to the well head. The existing pump wires are not in conduit (direct burial), and there's a paved driveway between the building and the well head.
So yesterday I installed a power line carrier (PLC) transmitter and receiver.
In this new setup, the wires to the well head are now always energized, wired to both the heat cable and the small receiver in the well head. The receiver is basically just a remote-controlled relay, wired to kick on the pump when energized. The transmitter is mounted in the building next to the pressure switch. I have two wires going from the pressure switch to the transmitter's "trigger" terminals. The transmitter just needs to see a close across those two terminals and it will send a signal across the existing wires to energize the relay at the well head. Once the pressure switch is satisfied, it creates an open across the "trigger" terminals, and the transmitter kills the signal, de-energizing the receiver relay, and shutting off the pump.
Fairly simple. And it all works like a champ, except...
The "trigger" terminals are not seeing the pressure switch close. And this is the same pressure switch that worked fine when connected to 240V! I read zero ohms with the meter, but it's like something with the internal workings of those contacts isn't compatible with the transmitter's input circuitry. When I touch a jumper wire across the pressure switch terminals (which are still wired to the transmitter input), the transmitter's "transmit" light immediately turns on.
So it seems the solution is to either install an add'l relay (which adds more complication), OR, has anyone heard of a pressure switch with contacts better suited for this application? Any other thoughts?
Thank you!
A little background:
I inherited a situation here in NC in which the above-ground portion of pipe will freeze at the well head. With the goal of installing some heat cable and pipe insulation, I want to provide a constant source of power for the heat cable. Unfortunately, there's no simple way to get an extra set of wires out to the well head. The existing pump wires are not in conduit (direct burial), and there's a paved driveway between the building and the well head.
So yesterday I installed a power line carrier (PLC) transmitter and receiver.
In this new setup, the wires to the well head are now always energized, wired to both the heat cable and the small receiver in the well head. The receiver is basically just a remote-controlled relay, wired to kick on the pump when energized. The transmitter is mounted in the building next to the pressure switch. I have two wires going from the pressure switch to the transmitter's "trigger" terminals. The transmitter just needs to see a close across those two terminals and it will send a signal across the existing wires to energize the relay at the well head. Once the pressure switch is satisfied, it creates an open across the "trigger" terminals, and the transmitter kills the signal, de-energizing the receiver relay, and shutting off the pump.
Fairly simple. And it all works like a champ, except...
The "trigger" terminals are not seeing the pressure switch close. And this is the same pressure switch that worked fine when connected to 240V! I read zero ohms with the meter, but it's like something with the internal workings of those contacts isn't compatible with the transmitter's input circuitry. When I touch a jumper wire across the pressure switch terminals (which are still wired to the transmitter input), the transmitter's "transmit" light immediately turns on.
So it seems the solution is to either install an add'l relay (which adds more complication), OR, has anyone heard of a pressure switch with contacts better suited for this application? Any other thoughts?
Thank you!