Posted 9 Jan 2019 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 Share this post Link to post Share on other sites
Posted 9 Jan 2019 (edited) The 'internal power bus' refers to the 5v and 12v supplies across the backplane to all attached modules- this is for the control circuitry (module processors etc) and has nothing to do with external voltages such as input/ output cards. These voltages need to be supplied externally and fused as recommended in the necessary documentation. The internal bus voltage is stepped down accordingly from the Power Supply Module (ie the first fixed modult to the left). This power is required for all initial PLC operation. Regards Daniel Edited 9 Jan 2019 by collinsd70 Share this post Link to post Share on other sites
Posted 9 Jan 2019 See attached a wiring diagram for IA4 Auxilarry wiring. Share this post Link to post Share on other sites