qwsoftware
Member
Hi guys,
I have 2 separate power supplies (240VAC mains to 24VDC - both 10A @24VDC). The fan draws 8A hence its own power supply and the other is for the PLC and its I/O.
The fan has 3 contacts, 0VDC, 24VDC (this is where the first power supply connects to.
The 3rd contact on the fan is control input (24VDC on this contact to start the fan) - The PLC switches this and the PLC and control is fed from the 2nd power supply.
All simple but the fan will not start as the voltage between the fan control input and 0VDC on the fan is not 24VDC as separate power supplies at different potential. I don't want to use a relay as space is limited but my question is can I just common up the power supplies 0VDC only so this fan will run as 0VDC on both PSU at the same potential?
I cant see any reason why not as I am not paralleling up the power supplies so no diodes etc required and the fan can only draw power from the fan PSU and the PLC/control from the control PSU?
I have 2 separate power supplies (240VAC mains to 24VDC - both 10A @24VDC). The fan draws 8A hence its own power supply and the other is for the PLC and its I/O.
The fan has 3 contacts, 0VDC, 24VDC (this is where the first power supply connects to.
The 3rd contact on the fan is control input (24VDC on this contact to start the fan) - The PLC switches this and the PLC and control is fed from the 2nd power supply.
All simple but the fan will not start as the voltage between the fan control input and 0VDC on the fan is not 24VDC as separate power supplies at different potential. I don't want to use a relay as space is limited but my question is can I just common up the power supplies 0VDC only so this fan will run as 0VDC on both PSU at the same potential?
I cant see any reason why not as I am not paralleling up the power supplies so no diodes etc required and the fan can only draw power from the fan PSU and the PLC/control from the control PSU?