I would like to throw this one up for discussion:
In my first job, all the schematics where numbered sequentially with wire numbers and terminals numbered via %N.
I recently was involved with a project where the schematics were numbered based on groups (000-099, 100-199, etc) and the wires where generated as %S%N and terminals were based on wire numbers or PLC I/O addresses.
Now keep in mind that the schematic sheet numbers jumped around a lot with big gaps between groups. The grouping was created for function grouping; AC power, AC Control, DC Control, Safety Circuits, etc.
I have now been tasked with converting a company from JIC/NFPA to IEC Schematics.
I would like to maintain the drawing modularity that is provided by using drawing number grouping but I feel like I am stumbling over the terminal numbers. I realize I can create uniqueness by using the location code and each terminal's product code for the terminal number but this does not account for gaps in the numbers caused by grouping that using %S%N does. Using this format though ends up creating very large terminal numbers (100.12) for Sheet 100 terminal 12 which do not fit on the terminal tag.
How does the rest of the community's IEC users handle this?
Ace User since 1998
The terminal brand we use at our workshop have a terminal group marker carrier as part of their range.
This takes a label which can define the group and have the terminals just holding the terminal number. Using your example of terminal 100.12, The carrier would have a label reading 100 and the terminal would have a number 12.
However, we group terminals by function and not sheet or group. This means in a complete panel we have4 terminals groups. These are incoming CT wiring, incoming VT wiring, Bus wiring (between panels but still inside the board) and finally Customer/multicore wiring which leaves the panel for customer equipment. We can also add extra groups according to customer requirements, like a group for CT ratio selection/testing.
You may recognize me from the
hundreds of previous newsreader posts
I've made over the last 5 years
as Brad Coleman