Relays

[Artisan]

The truck I speak of is an M916 but I am assuming this question is generic.

In TM 9-2320-273-20 it states that all the relays "are identical".

When I read the description for each relay I see #1 thru #6 relays are
"Normally Open Circuits", but then #7 and #8 relays are "Normally Closed Circuits"
Can someone clue me in here?

Is it they are just wired differently?

Trying to learn electrical...

 

[wheelspinner]

Yes. There are two power out options 87/87a maybe? One is NO one is NC

 

[Tow4]

Looking at the wiring diagram, the relays are wired differently. All of these relays in my M915A1 are the same if I'm not mistaken.

Terminal 30 is the input and terminal 87 is a Normally Open output when the relay is not energized, 87A is a Normally Closed output when the relay is not energized.

 

[papakb]

Relays can come in hundreds of different configurations as far as the numbers of contacts and the number pins but basically they are all similar. NO stands for a set of contacts that are Normally Open and NC means contacts that are Normally Closed with the relay in a de-energized situation (no power to the coil). The relays themselves can all physically be the same relay, however, the way the wires are connected to them determines if they are used in an NC or NO application.

Kurt
KG6KMJ

 

[Artisan]

I guess I need to look at the schematic and see if I can see
how #1 thru #6 are wired different then #7 and #8

Yes tow, I believe they are all identical relays.

 

[Artisan]

If anyone is interested, I have been interjecting copious
amounts of info regarding relays recently in the
Artisan's M916 thread. Pages 43 and 44 I believe.

Crazy but the thread have about 20,000 views to date.

Lots of GOOD info for the 20Ton / M915 Series Guys