Worksheet for System Power Requirements

To calculate the number and type of system power supplies required to power the system based on the 12 VDC LocalBus power requirements calculated in the Worksheet for Products Using 12 V LocalBus Power and 24 VDC Bussed Field Power, use the following table for systems in which the system power supply is powered by a 24 VDC supply or use the Worksheet for System Power Requirements - 12 VDC for systems in which the system power supply is powered by a 12 VDC supply. Remember to not exceed 8 A on the horizontal carrier and 15 A on the vertical carrier and remember to include calculations for redundant system power. Add Subtotal 1 from Worksheet for Products Using 12 V LocalBus Power and 24 VDC Bussed Field Power and Subtotal 2 from the Worksheet for products Using Only 24 VDC Power to do the calculation

Table: System Power Requirements - 24 VDC Input
Product Type	Amps Required for Each Product		Total for Product Type
Product Type	12 VDC	24 VDC	12 VDC	24 VDC
System Power Supply (Dual DC/DC) 24 V input Provides 8.0 Amps @ 12 V (Subtotal 1 /8.0 A = Quantity)⁽¹⁾	N/A	7.5 max	N/A
Redundant system Power Supply (Dual DC/DC) 24 V input for either Simplex or Redundant controllers (if applicable)	NA	1.0 max⁽²⁾	N/A
Add for Subtotal 3		Subtotal 3	N/A
Add Subtotal 1 (24 VDC only) from Worksheet for Products Using 12 V LocalBus Power and 24 VDC Bussed Field Power.		Subtotal 1	N/A
Add Subtotal 2 from Worksheet for Products Using Only 24 VDC Power		Subtotal 2	N/A
Add Subtotals 1, 2, and 3 for total 24 VDC power required.		Grand Total	N/A

⁽¹⁾ Older models of the Dual DC/DC System Power Supply provided 4.5 A of +12 V power and required 4.0 A input from +24 V power.

⁽²⁾ If your system requires redundant system power, a redundant system power supply can be added to either a 2-wide horizontal carrier, (may require an additional 2-wide carrier) or to the 4-wide vertical carrier.

Example Calculation for 24 VDC Input

As an example, suppose your calculations from the Worksheet for Products Using 12 V LocalBus Power and 24 VDC Bussed Field Power showed that the total 12 VDC LocalBus power requires 6.1 A. Calculate the number of power supplies that you will need as follows:

6.1 A/8.0 A/supply = 0.76 or 1 system power supply for simplex power

If redundant power is required, an additional 2-wide carrier is necessary for a horizontally mounted DeltaV system. Use the Worksheet for Legacy Bulk Power Requirements to calculate the number of bulk supplies required to power the system for each type based on the 12 and 24 VDC power requirements calculated in the Worksheet for System Power Requirements - 24 VDC Power Input.