Here is how it will always play out. The game has rules we need to follow. Wire, all wire has resistivity or resistance. There are formulas we can use to calculate the resistance of for example solid core copper wire. Here is an example of a chart. Using AWG 12 wire as an example the resistance would be 1.588 Ohms. That is One Way single conductor. Round trip we get a Resistance total of about 3.17 Ohms. Now here is the nice part of having the higher voltage. A 24 VDC 5 Amp rated supply has a primary side, just as an example 24 Volts at 5 Amps = 24 * 5 = 120 Watts. Let's call your loads a maximum of 3.0 Amps. So 24 * 3 = 72 Watts. That is the power and that 72 Watts at 120 Volts = 0.6 Amp. So now you have 21 stations let's say at 0.6 amp each or a total of 12.6 Amps. Even using AWG 10 wire the drop would be about 26 volts getting down around 94 volts but most SMPS power supplies run find down to 90 VAC in. Granted this assumes the load at the end of line. WE take the wire resistance times the current to get the voltage drop.

Yes, the shorter the run (distance) the lower the I*R drop of the wire. Matter of fact, in my example, with a 150 foot run, same load(s) the total drop would be about 3.9 Volts.

This is why higher voltages are chosen for long transmission runs.

Ron

Even better is to run 240VAC or 440VAC and use a transformer to get back to 120VAC. Then just plug and chug those power supplies.

 

Even better is to run 240VAC or 440VAC and use a transformer to get back to 120VAC. The just plug and chug those power supplies.

Yeah, agree. Just used 120 because it is what my mains was but actually in the plant we had plenty of 240 and 480 available. No clue what our thread starter has?

Ron

 

They probably don't wanna have any active electrical components in clean room!

?? But the devices are active if you're running a supply to them and they're working!

 

?? But the devices are active if you're running a supply to them and they're working!

I know it's the same thing but my guess is that once installed they may use NEMA 4X type cover to make it waterproof for washdown purpose. There are cGMP guidelines which they strictly follow.

 

Yeah, agree. Just used 120 because it is what my mains was but actually in the plant we had plenty of 240 and 480 available. No clue what our thread starter has?

Ron

I will need to look into this as I don't have any such information as of now.

The second solution might be install pneumatic actuator instead of electrical actuator and make it work from solenoid banks. Not sure what will happen if air has to travel this far in 6mm OD tubes!!!

 

The second solution might be install pneumatic actuator instead of electrical actuator and make it work from solenoid banks. Not sure what will happen if air has to travel this far in 6mm OD tubes!!!

Oh yeah, I have been to that Rodeo many times. Miles of copper tubing throughout a sprawling facility. Some for heating/cooling some for operating huge valves with giant bellows. Also plenty of I to P transducers where 4 to 40 mA becomes 3 to 15 PSI. The pneumatic was really cool and reliable.

Ron

 

install pneumatic actuator

 

install pneumatic actuator

That seems to be the only solution right now.

 

That seems to be the only solution right now.

Well with the distance involved pneumatic can be a new best friend. Only you know what is or is not acceptable at the site location.

Ron