Emerson ControlWave User Manual

ControlWave Instruction Manual (CI-ControlWave)
Revised Nov-2010 Installation 2-11
Calculating the
Maximum Current
Required
Use the following formula to determine the maximum current required
for the +24 Vdc bulk power used with a particular ControlWave:
Max Bulk +24 Vdc Supply Current = CPU
max_current
+ Σ I/O Module
max_curren t
where
:
CPU
max_current
refers to the maximum current required by the CPU (with or
without an SCB), backplane and the PSSM. This is 1A.
Σ I/O Module
max_current
refers to the sum of the maximum current required by each
and every I/O module installed in the unit. The amount per
I/O module varies as follows:
16 AI Module 2A per module
8 AI Module 1A per module
8 AO Module 1A per module
16 DI Module 1A per module
32 DI Module 1A per module
16 DO Module See table (no surge current)
32 DO Module See table (no surge current)
6 UDI Module See table (no surge current)
4 RTD Module See table (no surge current)
6 LLAI Module See table (no surge current)
So, for example, if you have a ControlWave with a 16AI module, an
8AO module, and a 32DI module, the maximum current draw is 1A for
the CPU plus 2A for the 16AI module plus 1A for the 8AO module and
1A for the 32DI module, for a total of 5A.
Note: This calculation covers current draw during normal operation
(steady state) as well as the current draw during power-up in-
rush when the unit is first powered on. Power up in-rush current
can last up to 100 milliseconds and is higher than the current
draw required during normal operation.
Refer to Table 2-1 for ControlWave steady state and loop current
requirements for bulk power supplies.

Emerson ControlWave Specifications

General

Brand	Emerson
Model	ControlWave
Category	I/O Systems
Language	English