Relay contacts connection

[ele.engineer]

My dears,
I'm wondering if it is possible to use two different contacts with two different power sources (24 and 120 VDC) for the same relay ?
I'm not sure that this situation is allowed by code.

 

[ScottyUK]

If the contacts are suitably rated and galvanically isolated then yes, no problem in principle. Obviously separate voltages can't be switched by the same contact pair, nor can two differing voltages readily drive one relay coil.

 

[waross]

It depends on the Authority Having Jurisdiction and your local codes.
At one time some applications needed a special relay with the operating coil/solenoid separated from the contacts by a barrier to meet code rules when the coil voltage or supply was different from the switched voltage or supply.
If this is allowed by your code then all the contacts should, and under many codes must, be rated for the highest voltage used.

I'm not sure that this situation is allowed by code

This is a world wide forum. Which code do you work under?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ele.engineer]

Thanks waroos and I mean ANSI code, is it allowed for ANSI code ?

 

[itsmoked]

Yes, you can use different CONTACT SETS in a relay for different voltages as long as the contacts are rated for at least the highest voltage involved.

Keith Cress
kcress -

http://www.flaminsystems.com