monkey77

Hello All, I will first state that I am very new to the world of PLC's. I do the control drawings where I work. I'm trying to figure out the 1734 Point IO, specifically the 1734-IA4. The manual states "Module power is supplied from the internal power bus". Does this mean I do not need to run ANY power wires to the modules? The installation manual shows points 4,5,6 and 7 as "L1" wires?? The system I am designing, from left to right has the following: 1794-PS13, 1734-AENT, 1734-FPD, Followed by Qty. 11 1734-IA4's. I'm bringing 120VAC and 24VDC to the 1794-PS13. From the 120VAC terminals, I run wires to the FPD. From the 24VDC terminals, I run wires to the 1734-AENT. On the first 1734-IA4, I would think I should bring any power there, because its already back plane fed...….correct? Or DO I run power wires there? Thanks in advance

Hi All, I am pretty new at electrical design for PLC control panels. We are a UL508A shop, so this is the code I refer to most. Something struck me as odd when I was trying to size wire for this control panel. UL508A 28.3.1 says this: The required size of the field wiring terminal shall not be less than 14 AWG (2.1 mm2) and shall be determined by: a) Calculating the required ampacity per 28.3.2 – 28.3.6; and b) Determining the minimum field wiring conductor size from Table 28.1 having a corresponding ampacity that is equal to or greater than the required ampacity from (a). How can the minimum wire size be #14 AWG? We use #16 AWG for wire to the PLC modules? Are we breaking code or is there something I am missing? Also, understanding code books can be difficult. Is there a website or place I can go to get a plain English translation? I feel like I will read a sentence over and over again to try to understand what they are saying, and feel like there's is a much easier way to say it than the way it is written. For example, "28.3.1 b" ……...what is it really saying?  

Thanks for your replay jimtech67

Ken, thanks for your reply. The selection guide really helps. Someone else created this system in the Integrated Architecture Builder utility, therefore I didn't have to figure out the calculations. I have one final question. In the image I have attached, it shows 12/24vdc coming into the ADN, points 4 and 6. The dark solid lines leaving ADN, points 5 and 7, I assume that I can hard wire from those points to the next expansion power supply EP24VDC? And I assume the dashed lines are the internally connected bus?   PLC_POINT IO_SELECTION GUIDE.pdf

I am definitely a newbie in the world of PLC's. So I hope this doesn't sound like a dumb question. I do the electrical design for PLC's and have only done this for a few short months. I am currently working with a Point IO PLC. This is the first one I've seen. Because of the qty. of input and output modules, we had to add 1734-FPD and 1734-EPAC to boost the power. Easy enough, I get that. I bring power to the 1734-AENTR.....then, do I hard wire to the next module, or are the next adjoining input/outs connected view the internal power bus? Same question goes for the 1734-FPD and 1734-EPAC. I understand to bring power to those devices, but do I hard wire to the first module or is it automatically connected via internal power bus? I have done my research before I posted on this site. I think some of the installation manuals for these devices are conflicting., I think that's why I'm so confused. Thoughts? Does anyone know of a good trusted manual for such a question. Thanks in advance

Thank you for your help

oK, makes sense. When you said "daisy Chaining" - did you mean hard wire daisy chain or internal bus wire daisy chain?

I am definitely a newbie in the world of PLC's. So I hope this doesn't sound like a dumb question. I do the electrical design for PLC's and have only done this for a few short months. I am currently working with a Point IO PLC. This is the first one I've seen. Because of the qty. of input and output modules, we had to add 1734-FPD and 1734-EPAC to boost the power. Easy enough, I get that. I bring power to the 1734-AENTR.....then, do I hard wire to the next module, or are the next adjoining input/outs connected view the internal power bus? Same question goes for the 1734-FPD and 1734-EPAC. I understand to bring power to those devices, but do I hard wire to the first module or is it automatically connected via internal power bus? I have done my research before I posted on this site. I think some of the installation manuals for these devices are conflicting., I think that's why I'm so confused. Thoughts? Does anyone know of a good trusted manual for such a question. Thanks in advance