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Electrical symbol on Asian ship

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What is that symbol? A temperature control manual reset switch?? I'm on an Asian ship and these schematics are throwing me off

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Did you look through all the sheets for a legend?
Every decent set of plans has a legend.

Don't hesitate to contact the person who signed the plans for information.
It's their job to communicate intent and they came up short if you can't interpret their work.
 

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@Mbit would know.
If I had to guess from the small part of the print you shared it is an emergency call button for a refrigerated area if someone get locked in. The lights come from the alarm and the unit is csc21, Call station in compartment 21.
 
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I searched on-line, because I've never seen this symbol... on one of the CAD sites, it calls it a change over switch or an intermediary change over switch..
Found it here

@Mbit would know.
If I had to guess from the small part of the print you shared it is an emergency call button for a refrigerated area if someone get locked in. The lights come from the alarm and the unit is csc21, Call station in compartment 21.
I agree with the call button.. "Help! let me out!"
 

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Discussion Starter · #9 ·
I thought it was a temperature switch because I was troubleshooting a frozen expansion valve and I had the door wide open. Looks like I probably just bumped the call button lol I had no sleep from doing cargo the night prier. But I just slept for 12 hours so this makes sense now lol thanks guys
 

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One more reason to hate IEC style of drawings:
No full description next to the symbol.

The description on drawings should match the description on the tag/label on the machine.
One good thing about IEC drawings is they're very standardized. Having seen european equipment from 40 years old to brand new, the newer stuff is extremely consistent in the way it is drawn. They do over abbreviate though and a lot of the symbols make no sense e.g. their flow, float and pressure are dumb. Another example is the timing relays. You just have to know the symbols wheras NEMA will tell you NOTO, NOTC etc.
 

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This is a comparison list for NEMA to IEC for symbols in prints.

For your shop space, in the corner of the machine room.
That's a great find.

Maybe @Dennis Alwon will add it to his Resources directory.

On the first entry, what they call NEMA capacitor symbol is what the electronics industry uses for Electrolytic Capacitor.
What they call IEC capacitor is what we use for Ceramic Chip Capacitor, so at times we see both symbols on a plan.
Specifically, Texas Instruments does it this way and it makes it easy to see an application design to know what's involved without digging up the part numbers and looking up the parts.

For me, I prefer to avoid the electrolytic caps due to their history of failure (think Dell computer motherboards in the 1990's and forward).

With today's modern buck converters we can buck 24VDC down to 3.3VDC with only ceramic chip caps and an inductor, with very low ripple and nearly 90% efficiency.
 

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That's a great find.

Maybe @Dennis Alwon will add it to his Resources directory.

On the first entry, what they call NEMA capacitor symbol is what the electronics industry uses for Electrolytic Capacitor.
What they call IEC capacitor is what we use for Ceramic Chip Capacitor, so at times we see both symbols on a plan.
Specifically, Texas Instruments does it this way and it makes it easy to see an application design to know what's involved without digging up the part numbers and looking up the parts.

For me, I prefer to avoid the electrolytic caps due to their history of failure (think Dell computer motherboards in the 1990's and forward).

With today's modern buck converters we can buck 24VDC down to 3.3VDC with only ceramic chip caps and an inductor, with very low ripple and nearly 90% efficiency.


Done.. Thanks
 
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Different countries and regions express different electrical symbols! It's a button that looks like a two-contact button normally open. If you come into contact with EPLAN, you will find different standards in different regions. Generally, everyone uses IEC standards.
 

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That's a great find.

Maybe @Dennis Alwon will add it to his Resources directory.

On the first entry, what they call NEMA capacitor symbol is what the electronics industry uses for Electrolytic Capacitor.
What they call IEC capacitor is what we use for Ceramic Chip Capacitor, so at times we see both symbols on a plan.
Specifically, Texas Instruments does it this way and it makes it easy to see an application design to know what's involved without digging up the part numbers and looking up the parts.

For me, I prefer to avoid the electrolytic caps due to their history of failure (think Dell computer motherboards in the 1990's and forward).

With today's modern buck converters we can buck 24VDC down to 3.3VDC with only ceramic chip caps and an inductor, with very low ripple and nearly 90% efficiency.
NEMA symbols are for electrical drawings, not electronics, so there would be no differentiation between types of capacitors, it’s just a capacitor, and in electrical drawings, usually Power Factor Correction caps or motor starting caps are the only ones we see.

The concept of a legend sheet is our standard here, because we don’t always adhere to any national standards for drawing symbols. But elsewhere in the world that uses IEC standards, they are rigidly specific, so they don’t use a legend sheet because they expect anyone qualified to work on it to be well versed in IEC symbology. Unfortunately they don’t care that people here are generally NOT trained on or even exposed to IEC symbology.
 

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I reviewed and quick studied the comparison between the symbolic nature of the two styles.
I do feel the NEMA presentation presented a more realistic depiction of what the desired application
was trying to do. In most cases it had more detail to the application and less of a "stick" drawing aspect.

I am also thankful to the expertise of long time readers and contributors that clarify most situations that
the average reader doesn't have to usually deal with. The wealth of knowledge has been great, Thank you.
 
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