The legacy bulk AC to 12 VDC and 24 VDC to 12 VDC power supplies provide 12 VDC power to the System Power Supply (Dual DC/DC) for one or more controllers and their associated I/O subsystems. However, if you are using the bulk power supply to provide power for more than one DeltaV system or for other equipment, refer to the I/O card specifications or use the simplified calculations in the installation worksheet to determine if there is sufficient capacity.