Quote:
Originally Posted by N147JK
Hmmmm I'm not following you. A mechanical relay where? For what purpose?
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When you see the spec for the load rating 30 VAC/DC it implies that a mechanical relay is used to control the load.
In the picture below the solenoid uses a DC voltage to generate enough current in the coil to close the contacts (i.e. electromagnet). However, the load circuit can be completely independent of the solenoid control and can be higher or lower voltage and AC or DC. The mechanical contacts don't care.
I had found an HVAC website where someone was looking for recommendations for a thermostat. The locals were giving him a bit of a tough time. They told him to buy a relay with a mechanical relay (one that clicks). Well, this is not easy buying online and the thread went on and on with how to tell if the thermostat had a mechanical relay.
There are also solid state relays and this site does a comparison.
https://www.ia.omron.com/support/gui...roduction.html
Not wanting to make this a science project I just wanted to confirm that the van application was for a 12VDC load despite the thermostats being typically used for 24 VAC loads.
It sometimes confuses engineers when you specify a voltage but not if it is AC or DC (i.e. VAC or VDC)
You will notice in your table some of the use cases are for 24 volts and the one you pointed out is 12VDC. So what is the 24V? VAC or VDC? It is kind of a guessing game.