Relay Symbols

[rvim002]

Hi

I am dealing with a schematic that has old relay symbols. I have decoded all except one.

I have scribbled my understanding in the attachment.

Please advise if I am on the right track.

Cheers

 

[CAPS]

I can't find a protective function 23. The contact symbol appears to be a flow switch. Is there any cooling in you system?

 

[zog]

I can't find a protective function 23. The contact symbol appears to be a flow switch. Is there any cooling in you system?

23- TEMPERATURE CONTROL DEVICE is a device that functions to raise or lower the temperature of a machine or other apparatus, or of any medium, when its temperature falls below, or rises above, a predetermined value.

 

[Jraef]

I'm not aware of a different symbol used just because a relay has a flag on it or not, the flag is a visual indicator for when someone is physically looking at the relay, it makes no difference in the operation and I can't see a purpose for having a special symbol for it in a diagram. I've never run across that either.

That symbol, as mentioned above, is much closer to looking like a JIC Flow Switch contact, although usually they are not shown as Double Break like that. IEEE 23 is a temperature relay function, but the JIC wiring diagram symbol for that is different.

Common JIC standard wiring diagram symbols

 

[rvim002]

Thanks guys

 

[jim dungar]

Just be careful with the references sources you use.

Protective relaying symbols can be drastically different than the machine control symbols posted by Jraef.

The US power industry has quite a few "typical" symbols, however there is no single set of "standardized" ones. It is not uncommon to find each large company with their own symbols nomenclature. The US machine control and process industry is much better at standardization, and the Europeans are probably the 'gold standard'.

I would not be surprised to finds that your "flag" is really a time delay function instead.

 

[Jraef]

Just be careful with the references sources you use.

Protective relaying symbols can be drastically different than the machine control symbols posted by Jraef.

The US power industry has quite a few "typical" symbols, however there is no single set of "standardized" ones. It is not uncommon to find each large company with their own symbols nomenclature. The US machine control and process industry is much better at standardization, and the Europeans are probably the 'gold standard'.

I would not be surprised to finds that your "flag" is really a time delay function instead.

Good point. I jumped to "control" with relay, forgot about "protection"