K
KirkC
I like having DC+ and DC- distinguishable. DC+ is conventionally solid blue. Blue with white stripe is fine for DC-, but it's a special order. For a medium or large panel shop that's no problem.
I build some simple control panels in my garage, the others I send to a panel shop. It's not worth my while to buy a spool of blue/white, so I use gray for DC- in that case.
One glitch in wire coloring schemes arises with solar powered panels. You can chain two 12VDC solar panels together to make 24VDC, but one 12VDC solar panel with 12to24DC converter for analog loop power is simpler and less expensive. Control Microsystems has a niche market with 12VDC controller and an internal 12to24VDC converter to power analog loops. So you're left the problem of clearly identifying both 12VDC and 24DVC wires. There's no shortage of colors, but I'm not aware a convention to deal with that. To make matters worse, telecom equipment uses 48VDC with a positive ground as a standard.
I build some simple control panels in my garage, the others I send to a panel shop. It's not worth my while to buy a spool of blue/white, so I use gray for DC- in that case.
One glitch in wire coloring schemes arises with solar powered panels. You can chain two 12VDC solar panels together to make 24VDC, but one 12VDC solar panel with 12to24DC converter for analog loop power is simpler and less expensive. Control Microsystems has a niche market with 12VDC controller and an internal 12to24VDC converter to power analog loops. So you're left the problem of clearly identifying both 12VDC and 24DVC wires. There's no shortage of colors, but I'm not aware a convention to deal with that. To make matters worse, telecom equipment uses 48VDC with a positive ground as a standard.