bskeebers (Customer) asked a question.

December 9, 2021 at 11:34 PM
Power distribution to multiple 120 VAC modules?

Hello,

 

This may be a total n00b question, but I have 3 separate devices that all require AC input power:

-P301AC to power my Productivity3000 5-slot base

-PSE24-160 to provide 24 VDC to various field devices

-PSE12-230 to provide 12 VDC to various field devices

 

What is the best way to route the input power for these modules? I typically use power distribution blocks (i.e. busbars) for DC power but am not seeing any busbars that state that they are rated for AC.

 

I'm aware I should be running each live wire through a circuit breaker before feeding into the AC modules, but how do I split the power upstream from that? I have a single 120 VAC line coming into the control cabinet that I'd like to use to power these three (my current needs are minimal, I just need access to both 12 VDC and 24 VDC).

 

Any guidance would be greatly appreciated.

  • 5 answers
  • 2.09K views

  • AkaHammer (Customer)

    I do same as PouchesInc for the 120 VAC and 24 VDC to terminal blocks and jumpers to make several connections available, I try to keep it so only one wire per terminal so lots of connections available for like sensors, neutrals etc.. Heavier loads of 120 VAC power distribution blocks(rare thing). I like terminals that have the screw jumpers with strip, not plug in jumpers, had issues with those. And prefer spring terminals so they don't come loose with vibration where as screw terminal do just that, then occasionally tighten the screws on jumpers or if any weird things happen tighten all the jumpers again because with vibration and heating and cooling they have been known to work loose

    Last few years anything 480 VAC 3 phase I have been using Manual motor circuit protectors with line side busbar system, did not like this at first, but if done properly it is great.

     

    additionally I put barriers easily recognizable in terminal strips to separate the 120 from 24 volts, and color code for terminals.

    Again last few years started using fuse holders that can be bus bared together rather than power distribution blocks. Like Automation Direct fuse holder part # EHCC1DU-12 and busbar example part# EB1P100M15 and tap block to feed main power to busbar system part# EPWR1PLP-1

     

     

     

     

    Also use red wire for 120 vac control wires and blue wire for 24 vdc/ blue and white for 24 vdc com, and black for 480 vac 3 phase. Also green with yellow stripe for grounds and always put a lot of these.

     

    These things to me are good practice and make it easy to look at a panel and see what is going on quickly.

     

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  • PouchesInc (Customer)

    I use a group of terminal blocks connected with the proper jumpers. They are typically rated for 300v or 600v so you can distribute 120v or 240v power just fine in them. If you are doing any high current stuff, then don't do it in terminal blocks, but anything where the total load through all the blocks on that circuit are under 15A should be fine.

    https://www.automationdirect.com/adc/shopping/catalog/terminal_blocks#sort=undefined%20asc&start=0

     

    "barrier strip" type terminal blocks are also often used, especially in older machines. They are significantly cheaper than the typical terminal block you see nowadays, however, they do take up a lot more room. This is why most machines in the past 20 years or so switched to the now-standard terminal block. Control cabinet space is worth a premium.

    https://www.mcmaster.com/barrier-strips/terminal-blocks-11/

     

    I also do the same thing for breaking out my 24v power to a bunch of blocks I can pull my commons from since a power supply only has 1-2 output terminals.

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  • AkaHammer (Customer)

    I do same as PouchesInc for the 120 VAC and 24 VDC to terminal blocks and jumpers to make several connections available, I try to keep it so only one wire per terminal so lots of connections available for like sensors, neutrals etc.. Heavier loads of 120 VAC power distribution blocks(rare thing). I like terminals that have the screw jumpers with strip, not plug in jumpers, had issues with those. And prefer spring terminals so they don't come loose with vibration where as screw terminal do just that, then occasionally tighten the screws on jumpers or if any weird things happen tighten all the jumpers again because with vibration and heating and cooling they have been known to work loose

    Last few years anything 480 VAC 3 phase I have been using Manual motor circuit protectors with line side busbar system, did not like this at first, but if done properly it is great.

     

    additionally I put barriers easily recognizable in terminal strips to separate the 120 from 24 volts, and color code for terminals.

    Again last few years started using fuse holders that can be bus bared together rather than power distribution blocks. Like Automation Direct fuse holder part # EHCC1DU-12 and busbar example part# EB1P100M15 and tap block to feed main power to busbar system part# EPWR1PLP-1

     

     

     

     

    Also use red wire for 120 vac control wires and blue wire for 24 vdc/ blue and white for 24 vdc com, and black for 480 vac 3 phase. Also green with yellow stripe for grounds and always put a lot of these.

     

    These things to me are good practice and make it easy to look at a panel and see what is going on quickly.

     

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    Selected as Best

    • bskeebers (Customer)

      Awesome, great information. Thank you!

       

      I think I'll probably go with the fuse holders bus-barred together like you suggest. I'm looking at the product documentation for the comb-bus bar (link here), and have some questions based on the diagram on page 3:

       

      1. What are the differences between using the lower-mounted and upper-mounted direct-feed wiring lugs? Is there an advantage to using one or the other for power input, or is it simply a matter of convenience and wire organization?
      2. Is the comb-bus internally connected across all "comb" terminals? In the diagram there are red, black, and blue wires being fed into it the bus bar via the wiring lugs which is confusing. I would like to wire the busbar to my 120V hot wire via a single connection and have it feed into all connected circuit breakers. I do not want to find out that each "comb" is electrically isolated from the others.

       

      Thanks again for your help, I'm new to the forum and didn't expect quite such rapid and helpful feedback!

       

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  • Durallymax (Customer)

    You can buy a strip of copper bus bar for the Eaton breakers AD sells. Cut to length, incoming power goes to one of them.

    ​

    For common distributions of any type, Phoenix makes nice distribution blocks.

     

    20211212_140858

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    • 20211212_140858

    • PouchesInc (Customer)

      I went to look up that distribution terminal you have in the middle of your pic because it looked really nice. Also with the Dinnector D10X terminal blocks being out of stock AND going up in price by $50 I have started looking at alternate brands. That little block is WAY cheaper than Automation DIrect terminal blocks for common power distribution. Which is sad because even at the $50 price increase, Automation is still a small bit cheaper than competitor brands :( So unfortunate that terminal block pricing has gone up so much the past couple of years.

       

      Anyway, that 18 point distribution block is only $7.07 in a box of 8, or $6.70 for 3 boxes. Using 4 Dinnector D10X together to provide similar capability actually costs $13.28 now not including the jumpers needed, and takes up more din rail space, and technically provides 3 fewer spots for wires too.

       

      The smaller 6 point blocks cost $2.75, and the 12 point blocks cost $4.92

       

      Nice suggestion there Durallymax.

      Phoenix Contact # 3273110

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