Honeywell DO card issues
Thread Content
I would like to ask the experts: can a DO card in the Honeywell system be used to connect two solenoids to one channel?
This can be done; it’s equivalent to using a DO output to drive two parallel relays. You just need to check where in the circuit modifications are required. It is generally not done, as this reduces reliability and does not meet the requirements. The normal approach is to have two DO points, each controlling its own output.
Is this related to the output voltage or something similar, or is it simply not capable of handling it?
It should be possible to use 2 relays directly; you can first try and see if the two relays will activate and deactivate at the same time. But it is recommended not to do so.
With 1 relay; the relay has 2 contacts and is equipped with 2 solenoid valves
The consequence of doing this is frequent unexpected malfunctions
Add a 24V relay; the DO card supplies power to the relay separately, while the on-site solenoids also receive their own power supply at a separate point connected to the relay. In this way, there is no issue with pressure drop, and generally, an electromagnetic valve is used for control with isolation in between as well