Relay sharing common "COM"

[gabrielsoudry]

Hi,

I have several questions concerning the use of these relays with a common "COM" pin (like RO2.4 / RO2.5).

What are the use cases of these relays? Is it dangerous to use these common relays with outputs having different power supplies?

Finally, is it recommended for safety reason to use a different power source between the unipi power supply and the dry contact equipment (in input) ?

Thank you in advance for your reply,
Gabriel

[AVsetula]

Hi Gabriel,

You can find most of the information in the articles on inputs and outputs in the products section on our KnowledgeBase.

Below you will find the answers to your questions:

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What are the use cases of these relays? Is it dangerous to use these common relays with outputs having different power supplies?

• It depends on the specific circuit connection, but in most cases such a connection is undesirable.

Finally, is it recommended for safety reason to use a different power source between the unipi power supply and the dry contact equipment (in input) ?

• Yes

[gabrielsoudry]

@AVsetula Ok perfect thanks you !