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Drop flap relay - what is the definition (if translation correct) ?

Grossel

Well-Known Member
Hi.

During some minor upgrade of an old facility (from late 70's adn early 80's), I came over some electrical drawings describing something called "drop flap relay". That may or may not be a valid English name of the component, as that name is directly translated from the norwegian name "fallklaffrele".

From the drawings, I cannot tell if it is something special about this kind of relay, it is used as any other relay:
  • 110V DC voltage over coil.
  • On a 24V system, the relay contact just mirrors the state of the equivalent 110V line (usually a state of some mechanical component)
  • The relays are equipped with a visible marker, so it's possible to look at it and determine if the coil are energized or not.
The question remains: then what are a "drop fall relay", if it is not just the same as a common relay one can get everywhere ? And if someone know - what are the correct english term (if one exist) ?
 

rjenkinsgb

Well-Known Member
Most Helpful Member
I'd guess it is a trip relay, one that latches in once triggered and needs to be manually released or reset.

It may have a visual indicator flap or "flag" that shows once it is actuated.

If it is that, they appear to also be called "lock-out relays"
eg.
 

JimB

Super Moderator
Most Helpful Member
The expression "drop flap relay" does not make much sense in English.

As others have suggested as I am typing, could "flap" also mean "Flag", which is a word used for an indicator which goes up and down.

JimB
 

Grossel

Well-Known Member
Thank you for answering. I don't think it is a latcing relay (need to investigate that).

When I'm thinking about it, many of the functions are to relay error states. I'l have to look up the brand/name.

Can mention the obvious, that neither Google search nor google translate was able to provide any meaningful help.


[edit]
The full name of the relay in question: AEG RA32M

And the symbol used for it in electrical diagrams:
AEG RA32M symbol.png
 
Last edited:

dr pepper

Well-Known Member
Most Helpful Member
Do you mean a dolls eye indicator relay?
Dolls eye indicators were common at one time, and some had contacts to repeat the position of the eye.
Dolls eye refers to the indicator section, its a ball half black, and half red or other colour, when off its black, and when on t rotates to show red.
They were common where a bulb was not reliable enough, such as a missile ready indicator.
 

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