Help a Newbie with Schematic Symbols ^_^"

This site: Schematic Symbols, Electronic Symbols, Circuit Symbols

Has a very comprehensive library of symbols. I am schematically illiterate, so I use it whenever I need a symbol fix.

Welcome to CR4.

These look to be someone's interpretation of a mixture of IEC and ANSI one-line diagram symbols.

1. I think its a terminal, but Im not that sure, since it is connected to a circuit-breaker (which is connected to a transformator)

Generally, LP here in the US means Lighting Panel, which would make sense in your description.

2. Just to clarify, is 250A the current rating of the circuit breaker?

Yes

3. What does this "M" stand for?

Motorized usually. As in a "Motor Operated Circuit Breaker" or a charging motor

4. What does this "C" stand for?

That one has me stumped, I have seen "C" used in IEC circuit breakers to denote a Shunt Trip, but I can't find a reference to that to point you to. Could also mean it is a hand "Crank" charging mechanism, especially if the reference is Air Circuit Breakers (ACBs)

5. What does this "12 of" stand for?

Looks to me as though they are saying this is typical of 12 units of 100A breakers. As in "12 of these"

6. "EG" ?

Usually Engine Generator.

1. no clue, maybe you could post an example image.

2. probably, but without seeing, no one can know for sure.

3. M can stand for many things, again, please show us what you are talking about.

4. See #3

5. "12 of" probably means there are 12 of something

6. could mean "Equal Gain", could mean "Egypt" Could mean any number of things.

I propose you take some time to study the field you are trying to interpret through the schematic. Schematics are extremely valuable, and reading them is correctly is extremely important.

post your schematic, study up, and get back to us.

"... maybe you could post an example image."

He did! All of them.

Maybe the images are blocked by your server, but I can see them in his post.

Interesting, I guess they were blocked, Tried looking at them through multiple browsers with no success. My apologies, wish I could see them.

This work?

Im kinda stucked here with these symbols. Does anyone have any idea?

1. I think its a terminal, but Im not that sure, since it is connected to a circuit-breaker (which is connected to a transformator)

No images for me.. I guess I'm just not privileged enough.

Ohh well.

"2,3 & 4 are disconnect switches , not breakers"

I was thinking they were IEC breaker symbols, maybe you're right though. It's hard to tell without the context of the entire drawing.

1. It looks like a Lighting Panel.

2. Yes u r correct, 250A is the rated current of the circuit breaker.

3.M stands for motorized breaker. Motor(AC or DC) is being used for spring charging.

4. Am not sure about this. Supporting JRaef's reply, I feel that this is for cranking, which means the breaker spring shall be charged by hand. Pls correct me if am wrong.

5.12 off means, there are 12 nos of typical feeders of the type shown in the picture.

6. EG stands for emergency generator (which could be a diesel generator set which is put on-line only during the failure of mains power supply.

Rgds,

I have often seen the "C" used in #4 to indicate that the switch or circuit breaker has a dry contact associated with it to inform a control system of the open or closed state of the device.

Talk to whomever issued this drawing, they should have published a symbol list. Ask them for it.

Item #3 is a circuit breaker motor operated, necessited quantity = 1 of rating 2000 Amps (2 kA), closing and/or opening seems to be from an electrical spring motor (your pictures are almost unreadable)_It seems a main breaker of a general low voltage panel_

Item #5 is a circuit breaker manually operated, necessited quantity = 12 of rating 100 Amps_They seem distribution breakers_

Item #4 is a circuit breaker manually closed, necessited quantity = 1 of rating 400 Amps, closing by an electric coil and mechanism_

Item #2 is a circuit breaker manually operated, necessited quantity = 1 of rating 250 Amps_

I don't know what is item #1, may be a failure signal lamp?

I don't know what is item #6, may be a diesel driven generator of 99 kilowatts, which could be used to change a network frequency, because voltage and frequency are indicated, which is unusual in that type of scheme...Rectangle with circles (4, it seems?) denotes indications and/or signalisations of the generator panel (this generator is very small for having a generator panel and RPM denotes a diesel engine driven speed? May be a civil-work site generator... )

General symbols are in conformity with ISO standards schematic diagrams, which are understood by all electrotechnicians throughout the world (except, may be, certain anglophone ones ???)

BRZK