Gray insulators, Din Rails HELP!

Dear Delphiers,

Do you know if we are required to put the gray insulator in between the black and red blocks on the Din Rails distribution system? The FIRST manual doesn’t specify, except that the grays must go at the ends of the blocks (understandably). I see no reason for the gray in the middle, as the red and black blocks are already insulated from each other. It seems superfluous. Do you know if we are required to put the gray in the middle to pass inspection? If so, do you know of any loopholes to get around this (an official manual from the actual manufacturer, etc.)?


wild guess as to why the gray blocks are there: mechanical protection. The grey blocks clamp onto the din rail with a screw, the red and black blocks just clip on, and can slide off if not retained by the gray blocks.

There are two grey parts that were provided for this terminal block. The three blocks with the screws are the devices that tie the blocks to the rail. I recommend you use all three, one at each end and one in the middle, to keep the terminals snug. The grey spacers (thin grey parts) are meant for insulation between adjacent blocks. Although there should be no chance of electrical problems if you don’t use the spacer, they will provide additional mechanical isolation betweent the adjacent blocks.