Correct terminal block usage

Hello,

I purchased some Weidmuller ZQV 2.5 terminal block for a build that is in the design phase. As this is my first control system design/build i have a question on correct usage of terminal blocks.

In my system I plan for the plc to be sourcing for both inputs and outs. My plan was to use the terminal blocks to distribute the -24 DC to my outputs (a bank of relays) and to my inputs.

Currently my design has a -24 DC wire from a power supply going to a bank of terminal blocks which are jumped together with a jumper bar. The "top" terminals of the terminal blocks then distribute the -24 to the relays. This is where my question comes up. The "bottom" terminal of the terminal block bank is left empty. Is it proper to leave the bottom of the bank empty, or can i utilize these terminals to distribute the -24 DC to my inputs.

Thanks

Hi!

Welcome to the forum!

I cannot think of a reason why this should not be appropriate.
For relays, we usually daisy chain the negatives, but if you have got the space, terminals are a great way to do it.

There are relays that have bars to jumper the commons together.

This is one kind but there are others

http://www.mouser.com/images/microsites/PLC-PIT.JPG

That is the style of relay I am using, I was not aware there were jumpers available for them. That will be the rout I go.

Another question regarding this project. I have one motor that i need to turn on and off via the PLC. Motor is a 1PH 2HP 230V. I am trying to decided on a motor starter or contractor but am a bit confused. It is my understanding that if i go with the motor starter i do not need a breaker or fuse. But if i go with the contractor i would need to add a correctly sized breaker? Is this correct?

You need all 3. Breaker, Contactor, and Overload. Overload protects motor. Breaker protects entire circuit.

You could consider these in place of c/breaker & overload.
http://uk.rs-online.com/web/p/products/3515369/?cm_mmc=UK-PPC-_-google-_-3_UK_EN_M_A_and_C_Exact-_-allen_bradley%7Cmotor_protection_circuit_breakers&mkwid=scGcBqAdu_dc%7Cpcrid%7C78365102335%7Cpkw%7C140m+c2e+b40%7Cpmt%7Ce%7Cprd%7C&gclid=CKzQjrrnzs8CFc4V0wodcj0HkA

Steve

nehpets said:

You could consider these in place of c/breaker & overload.
http://uk.rs-online.com/web/p/produ...0|pmt|e|prd|&gclid=CKzQjrrnzs8CFc4V0wodcj0HkA

Steve

Click to expand...

Was thinking the same thing, but use a contactor to fire the motor. Single phase needs to be wired a bit differently with 3 pole stuff.