ronan
New Member
I need to install a very long (2140ft distance one-way, X2) DC control circuit run through a float switch to control a 220 vac, 1.5 hp submersible water pump in a well pumping up to a gravity feed tank. Tentative planned installation is a wide angle float switch in the water tank, with a solid state relay of some kind at the well, a DC activated relay with a low input current for the long run. I was planning or hoping to use the solid-state relay to control the power relay/contactor to the pump.
I have conduit installed already with three pull boxes to break up the pull distance plus it's on a steep slope so gravity is working in my favor when I go to pull the wire. I was figuring on a 24 volt power supply and was thinking of using 4 wire telephone cable and twisting wires together into two pair..? Basically looking for some relatively inexpensive wire that will get the job done. Any recommendations..?
So far this is what I have put together from online advise from a few people more experienced in motor control circuits, one of which was a pump guy whom has wired up a couple systems similar to mine in length.
Because of the long run and induction with AC the recommended advise is to use a solid-state relay that uses "logic level" input and high power output. It is recommended to use the solid-state relay to control the power relay/contactor as SSR's (Solid State Relays) tend not to be as good for switching inductive loads, such as pumps and motors.
Possible relay for the job: Omron Corp. G3NA-210B-DC5-24, Info at:
http://industrial.omron.ca/en/produ..._state_relays/panel_mounted/g3na/default.html
I ran the wire run resistance on this calculator: http://www.cirris.com/learning-center/calculators/133-wire-resistance-calculator-table
And for 4300 ft (up and back) of 20 gauge AWG wire it is 44 ohms. 22 gauge wire is 69 ohms. I am just not sure of how to figure out exactly how little current is required to activate the relay? Any recommendations on the best wire to use for this?
I was planning on the system using a 24 volt transformer run off one leg of the pump power supply I figured. I haven’t gotten to that part yet but I figured that’s not to complicated. Any recommendations?
This set-up seems pretty simple to me. It is just a DC power supply, a Solid State Relay, and a contactor! Any similar or better options advise?
One other thing that was mentioned was using a transistor-driven relay..? that required only a few milliamperes of current to activate the relay. I haven’t looked into that route.
Any opinions on the differences regarding reliability and simplicity between using a solid state relay to control the pump motor contactor and using use a transistor-driven relay that required only a few milliamperes of current to activate the relay…? Is one system better over the other for a long switch circuit such as this using small wire? I’m just trying to nail down my best option? The transistor-driven relay route was mentioned to me while researching this. A recommended part number would be great if someone had one!
Much thanks and appreciation for any advise
I have conduit installed already with three pull boxes to break up the pull distance plus it's on a steep slope so gravity is working in my favor when I go to pull the wire. I was figuring on a 24 volt power supply and was thinking of using 4 wire telephone cable and twisting wires together into two pair..? Basically looking for some relatively inexpensive wire that will get the job done. Any recommendations..?
So far this is what I have put together from online advise from a few people more experienced in motor control circuits, one of which was a pump guy whom has wired up a couple systems similar to mine in length.
Because of the long run and induction with AC the recommended advise is to use a solid-state relay that uses "logic level" input and high power output. It is recommended to use the solid-state relay to control the power relay/contactor as SSR's (Solid State Relays) tend not to be as good for switching inductive loads, such as pumps and motors.
Possible relay for the job: Omron Corp. G3NA-210B-DC5-24, Info at:
http://industrial.omron.ca/en/produ..._state_relays/panel_mounted/g3na/default.html
I ran the wire run resistance on this calculator: http://www.cirris.com/learning-center/calculators/133-wire-resistance-calculator-table
And for 4300 ft (up and back) of 20 gauge AWG wire it is 44 ohms. 22 gauge wire is 69 ohms. I am just not sure of how to figure out exactly how little current is required to activate the relay? Any recommendations on the best wire to use for this?
I was planning on the system using a 24 volt transformer run off one leg of the pump power supply I figured. I haven’t gotten to that part yet but I figured that’s not to complicated. Any recommendations?
This set-up seems pretty simple to me. It is just a DC power supply, a Solid State Relay, and a contactor! Any similar or better options advise?
One other thing that was mentioned was using a transistor-driven relay..? that required only a few milliamperes of current to activate the relay. I haven’t looked into that route.
Any opinions on the differences regarding reliability and simplicity between using a solid state relay to control the pump motor contactor and using use a transistor-driven relay that required only a few milliamperes of current to activate the relay…? Is one system better over the other for a long switch circuit such as this using small wire? I’m just trying to nail down my best option? The transistor-driven relay route was mentioned to me while researching this. A recommended part number would be great if someone had one!
Much thanks and appreciation for any advise