Rockwell Automation 284 ArmorStart User Manual - Manual (Page 441)

Appendix
F
24V DC Control Design Considerations
ArmorStart® DC Control Voltage
Application Information The maximum distance that an ArmorStart can be located from a
nominal 24V DC supply is determined by the inrush current
requirements (3.1A for 100 msec) of the 280, 281 and 283
ArmorStart Distributed Motor Controllers. The following table gives
the maximum distance from the power source that a single
ArmorStart can be placed.
Table F.1 Wire Gauge Sizes
In systems with multiple ArmorStarts (280,281 and 283) where more
than one unit will be commanded to start at the same time, provisions
must be made to account for maximum inrush current (710 mA for
100 msec for each unit). The dc power supply and distribution system
needs to be of sufficient capacity and the wire gauge of sufficient size
to handle the maximum current required. The total capacity of the
system also includes any additional loads connected to the
ArmorStart I/O outputs (max. 2 A for each ArmorStart).
The maximum distance can still be utilized if each of the ArmorStarts
that will be commanded to start simultaneously is wired directly back
to the dc power supply, or if a 100ms delay between consecutive starts
can be insured. When more than one ArmorStart is commanded to
pick up at the same time, the length of each wire segment in the
system should be multiplied by the number of units that can
simultaneously pick up through that section of wire. This calculation
represents the equivalent starting distance. The sum of the equivalent
starting distances should be less than the maximum distance allowed
for the selected gauge.
Example 1 – Conveyor Line Configuration
We want to wire up five sections of Conveyor (See Figure F.1). Each
section of conveyor has a conveyor motor and a diverter motor. Let’s
assume that they are 50 feet apart. The conveyor motors may be
started in sequence, but it is possible that all 5 of the diverter motors
could start simultaneously. All controllers are 280 ArmorStart units
with the HOA keypad. Let us assume that the conveyor motors are
sequenced on and are running before the diverters start.
Wire Gauge mm 2 Meters Feet
#16 1.31 38 125
#14 2.08 62 205
#12 3.31 100 325
#10 5.26 158 520