DIN rail mounted modules - layout conventions?
I am designing a module which I want to mount in a control panel enclosure alongside other DIN rail mounted modules. What is the convention for terminal positions when designing for DIN rail mounting? I have seen power IN at the bottom and power OUT at the top; is this usual? Would it be ok to have all the terminals at the top of the unit? Are there any conventions regarding the order or position from left to right? It would be helpful to know the reasoning behind any conventions.
Thanks for your assistance.
Posted Aug 29, 2023, 6:29 AM UTC
15
Typically you'll want to keep the heavier components like Power Supplies, Inverters/Drives and other things closer to the bottom just due to weight distribution. Personally I have always had the high voltage separated from low voltage as well. Inputs/Outputs in one section (always leave spares I also would separate the 110V I/O from things like a 4 -20mA I/I) 24VDC power has typically been wired as Brown for positive and Blue for Negative, AC has typically always been wired with Red wiring. Safety Circuits having the highest priority in terms of short runs and for the most part, yellow wiring was the standard. I've worked for many different companies and there was typically just the way that particular company did things. Example would be for one company strictly using Hoffman enclosures, Siemens Control Systems and Yaskawa Motor Drives for instance. While another used strictly GE etc. For the most part, however, the panels were organized by component type and power.
I mean for design of the DIN rail mounted module itself, not the overall cabinet layout. I'm doing a PCB design for a "soft-start" inrush current limiting device which will be connected to a large toroidal transformer mounted inside the control box enclosure. I want to know how DIN rail modules are usually wired, such as with the wires coming down from the top or up from below, or both, and what conventions if any. It makes sense to me to have the AC input at the bottom and output at the top but I'm wondering if it's ok to have all the terminals at the top as it makes the PCB layout easier. Alternatively I could have them all at the bottom. I just don't know whether there's a convention of keeping input and output on separate sides for example.
There's a standard used which is UL508A which is for industrial enclosure layouts- for the most part AC is typically at the top basically due to most panels having a main disconnect.