Allen-Bradley 1732ES-IB8XOB8 - Page 58

58 Rockwell Automation Publication 1791ES-UM001G-EN-P - November 2016
Chapter 3 Install the Module
I
OPDC
is the total output +24V DC power current through the female power
connector of the module (output +24V DC power current for the modules
that follow in the daisy chain).
I
OPM
can be approximated by dividing the number of watts for each type of
1732ES module by +24V DC as listed here:
• 1732ES-IB12XOBV2 - 1.56W
• 1732ES-IB12XOB4 - 1.08W
• 1732ES-IB8XOB8 - 1.56W
• 1732ES-IB8XOBV4 - 2.64 W
The table output +24V DC power calculation shows an example output
+24V DC power current calculation for a system of four modules. The output
+24V DC power voltage is 24V DC in this example. Module 1 is the first
module in the daisy chain. Modules 1 and 3 are 1732ES-IB12XOBV2 modules
and have bipolar safety outputs. Modules 2 and 4 are 1732ES-IB12XOB4
modules and have sourcing safety outputs. Fill out the table by starting with the
last module in the daisy chain, in this example Module 4. Once I
OP
is
calculated for module 4, it transfers as the I
OPDC
value for Module 3. This
process continues for all modules in the daisy chain.
As can be seen in the cell with value set in bold, the maximum output
+24V DC power current through the male power connectors in the daisy
chain is 9.02 A. This value is less than 10 A, so this system is adequate. The I
OP
value for a module in this system or any daisy chained system cannot exceed
10 A. If the value exceeds 10 A, the system fails to meet the maximum current
requirement for the module. The maximum current requirement is the
maximum current that any pin on the power connectors can carry, which is
10 A.
Table 15 - Output +24V DC Power Calculation
Value Module 1 Module 2 Module 3 Module 4
I
opdc
6.755 A 4.600 A 2.245 A 0.000 A
I
opm
0.065 A 0.045 A 0.065 A 0.045 A
I
so0
1.000 A 0.500 A 1.000 A 0.500 A
I
so1
– 0.500 A – 0.500 A
I
so2
1.000 A 0.500 A 1.000 A 0.500 A
I
so3
– 0.500 A – 0.500 A
I
so4
––––
I
so5
––––
I
so6
––––
I
so7
––––
I
SNSO
0.200 A 0.200 A 0.200 A 0.200 A
I
op
9.020 A 6.755 A 4.600 A 2.245 A