hi
what is the difference between in AC relay, and DC relay.

I am in impression that relay isolates the voltages between in and out,

so then in my view it does not matter whether i use AC, DC relay for ANY use.

i.e. i take 24 vdc relay where input is 24 vdc contact and output contact connected to 230 vac circuit. !!!!!

am i making some non-sense here ?

sorry i do not know , so need u guys help with some explanation

thanks

pandu

 

For each relay, there are 2 voltages and 2 currents to consider:
1. COIL voltage and current

2. CONTACT voltage and current

If you fail to heed the ratings of either you will either destroy the relay or it will fail to operate.

The COIL is what you energize using your driving (or source) contacts - for example, the field contacts or low energy contacts that you ultimately want to use to activate a higher energy device. So you connect these contacts in series with the coil and a compatible source voltage so that when these contacts close the relay coil energizes and moves its contacts. The coil is an inductive load, so if it is DC the field contacts have to be rated to interrupt the current drawn by an inductive load current equal to or greater than the current drawn by the relay coil. For an AC relay coil, inductive impact is less because the current through the relay coil passes through zero.

The CONTACTS carry the final load current and voltage, typically a higher voltage and current than the coil. They still have to be rated for whatever that voltage and current is, and if it is DC you must pay attention to whether or not the load is inductive.