AB PLC Tech Specification

Hi

I had a doubt in reading Tech Specification.

For all AB modules they mention that current drawn at 5.1V and current drawn at 24V what it exactly mean, as we are using 24V supply do i need to consider the current drawn at 5.1V for my power calculation.

Pls explain me.

If I understand you correctly and am guessing what you want, you want to put together a PLC rack. Like for CompactLogix. You must consider the current draw of both the 5 volt and the 24 volt.

You put in the 24volt power supply in the middle of the rack to distribute 5 volts and 24 volts on the backplane in both direction so it will not be overloaded. The modules use both 5 volt and 24 volt.

What I did was make an Excel spreadsheet and it helped me to "see" the current draw of the modules, both 5 volt and 24 volt, as I moved them from one side of the power supply to the other.

This is just me guessing at what you mean, hope it helped.

The PLC power supply input can be a variety of input voltages depending on which model you are using. 120/240vac and 24vdc are most common. Are you trying to size an external power supply for your DC powered PLC? As for the 5.1 volts, the power supply will provide both 24v and 5vdc to the backplane for the modules.

In most cases, the programming software can calculate the power budget for the backplane and tell you what size PLC power supply you need, so you don't have to manually add up the requirements for 5 and 24 volts for each modules. If you use certain 3rd party modules, you might need to supply that data. From there you can determine how to size the source you provide to it. The spec sheet of the chosen PLC power supply can tell you what size external supply you need to go with it.

Which PLC model are you working with?

Paul