I've been working with electrical schematics for quite some time, but I recently stumbled upon symbols representing loads that I'm not familiar with. Are these new additions or have they been around, and I've somehow missed them? Any insights would be greatly appreciated. Thanks!
Looks like a TPN isolator to me
Apologies, but that is NOT the symbol for an electrical disconnector (isolator, or isolating swich).
The "isolation" indicated with the box symbol in the OP is "separation" ("insulation") ... a very different concept.
A "single-line" or "schematic" version would be one of the symbols shown in J.3.2 of J.3.3 of IET Guidance Note 1, perhaps with "TPN" or "5P" (for 5-pole) next to it:
BS 7671 (Regulation 514.9.1) requires symbols on diagrams to conform to IEC 60617, so the use of the symbol in the OP for a disconnector type isolator (isolating switch) in a schematic or SLD is a non-conformity with BS 7671.
Not saying you are not correct, but I suspect the OPs drawing was not a schematic wiring diagram, but a stage 3 or 4 design LV schematic aligned with BSRIA BG6 levels of detail.
Please don't get me wrong, I'm not targetting criticism with the last post - it would be rare to come across diagrams that fully conformed because of "house standards" and the fact that to get access to the official IEC 60617 library is a huge cost.
In reality, doesn't matter whether it's wiring or schematic, the symbols in IEC 60617 are the same, as there are only two groups of symbols, one for architectural (positioning) drawings, and one set for schematic/wiring, although in reality they are for some symbols exactly the same.
Importantly, though, from a CDM perspective, if this is supposed to indicate an isolator (provided for safety), it's important to make sure someone working with this at the next stage is aware of that? Surely, this thread is a good example of why we need to adopt standards for drawings?
Incidentally, on the "slightly amusing" side, I think we mis-use the socket-outlet symbol on architectural (positioning) drawings, because the socket-outlet symbol is the single-line diagram symbol for a "socket contact" if you will, meaning the wiring goes in the back, and the "outlet" is the open side of the cup. We usually see these with the open side of the "cup" facing the wall (try and get your plug in there !):
If the cup is facing the wall, the symbol looks more like a plug with a stump of flex.
Just some context, this is schematically how a "plug contact" (bottom) in a "socket receptacle" (top) ought to be shown (ISO 7000 - 0354)
If the cup is facing the wall, the symbol looks more like a plug with a stump of flex.
Just some context, this is schematically how a "plug contact" (bottom) in a "socket receptacle" (top) ought to be shown (ISO 7000 - 0354)
