Cat-5 cable for peristaltic control?

[kdx7214]

I've got a Maomer brand peristaltic pump I'm getting ready to connect for ATO purposes. It's only a 2 wire device and a Cat-5 cable has 8 wires. Since it's low voltage (and frequency) DC, would I be able to run 4 of these pumps off of this? This particular cable is not shielded, although I do have some of that around as well.

Thanks!

 

[HuduVudu]

I've got a Maomer brand peristaltic pump I'm getting ready to connect for ATO purposes. It's only a 2 wire device and a Cat-5 cable has 8 wires. Since it's low voltage (and frequency) DC, would I be able to run 4 of these pumps off of this? This particular cable is not shielded, although I do have some of that around as well.

Thanks!

You would need to know what the amperage across the wires are.

Check to see what the parameters are for POE and match to those.

 

[DaJMasta]

Current is likely the limiting factor, according to a quick google the standard solid core conductors used as the twisted pairs in Cat 5 cable is about half an amp, so you'd need to be sure your device uses less than that.

In the case of PoE, the voltage is probably quite a bit higher than the pump you're trying to use so that it can deliver more power over the relatively low current rated lines, and you should not put any kind of mains AC levels over Cat 5 - the insulation is not rated to a high enough breakdown voltage.

So maybe you could, and you could double up wires to get about twice the current handling or use a DC-DC converter on the pump end to reduce a higher voltage over the line to what it uses and get more current delivery after the converter on the far end... but it doesn't sound worth it to me unless you have something that already has the jack in it that you're using on either end. Higher current rated stranded wire isn't all that expensive and can be found in pairs pretty commonly, and that would have more clearance for your pumps (or have enough current capability for them at all) as well as more flexibility and resistance to breakage when flexed, plus you wouldn't have to chop off the ends, rip off the jacket, and remove any shielding foil to use them.

 

[kdx7214]

Sorry about that, I was already well aware of the current limitations. I was more concerned with cross talk between pairs causing false triggers of other pumps. That's what I get for writing posts when tired lol

 

[foxt]

No issues with using the four twisted pairs to power four dc motors, as long as you're sure that the conductors can handle the load. Cross talk for dc power supply isn't an issue with this application. How long will the conductors need to be?

 

[DaJMasta]

If you are powering the pump through the Cat 5, there should be no crosstalk issues. You will get significant spikes from starting the motor and the inductance of the run, but if it's not a control signal it's definitely not going to induce enough current in adjacent conductors to start another pump. If these are high impedance, logic level control lines, then you may want to use a fairly low slew rate switch to reduce the chance of it (something like an RC switch debouncer with a schmitt trigger would do on the receive end), but even then, picking your choice of lines to match the twisted pairs in the cable and any internal shielding would help reduce issues.

 

[kdx7214]

No issues with using the four twisted pairs to power four dc motors, as long as you're sure that the conductors can handle the load. Cross talk for dc power supply isn't an issue with this application. How long will the conductors need to be?

They'll be short - maybe 2 feet at max

 

[kdx7214]

If you are powering the pump through the Cat 5, there should be no crosstalk issues. You will get significant spikes from starting the motor and the inductance of the run, but if it's not a control signal it's definitely not going to induce enough current in adjacent conductors to start another pump. If these are high impedance, logic level control lines, then you may want to use a fairly low slew rate switch to reduce the chance of it (something like an RC switch debouncer with a schmitt trigger would do on the receive end), but even then, picking your choice of lines to match the twisted pairs in the cable and any internal shielding would help reduce issues.

Fortunately this pump is an extremely simple one. It's just a 2 conductor with voltage either present or not, and that determining whether the pump is running. I think I'm probably going to go with using two conductors for each line (one set of twisted pairs for each). That way I can still run two motors off of it, and that should be sufficient for now.

Thanks