Manual

30 Rockwell Automation Publication DRIVES-IN001M-EN-P - March 2014
Chapter 2 Power Distribution
These recommendations are advisory and do not address all situations. Site
specific conditions must be considered to assure a quality installation.
Table 4 - AC Line Impedance Recommendations for Bulletin 160 Drives
EXAMPLE
The drive is rated 1 Hp, 480V, 2.7A input.
The supply transformer is rated 50,000 VA (50 kVA), 5% impedance.
Note that the percent (%) impedance has to be in per unit (5% becomes 0.05)
for the formula.
0.22% is less than 0.5%. Therefore, this transformer is too big for the drive.
Consider adding a line reactor.
IMPORTANT
Grouping multiple drives on one reactor is acceptable; however, the reactor
percent impedance must be large enough when evaluated for each drive
separately, not evaluated for all loads connected at once.
Bulletin
Number
Drive Catalog
Number
(1)
(1) Shaded rows identify drive ratings without built-in inductors.
Volts kW (Hp) Max Supply
kVA
(2)
(2) Maximum suggested KVA supply without consideration for additional inductance.
3% Line Reactor
Open Style 1321-
Reactor Inductance
(mH)
Reactor Current
Rating (amps)
160
-AA02 240 0.37(0.5) 15 3R4-B 6.5 4
-AA03 240 0.55 (0.75) 20 3R4-A 3 4
-AA04 240 0.75 (1) 30 3R4-A 3 4
-AA08 240 1.5 (2) 50 3R8-A 1.5 8
-AA12 240 2.2 (3) 75 3R12-A 1.25 12
-AA18 240 3.7 (5) 100 3R18-A 0.8 18
-BA01 480 0.37(0.5) 15 3R2-B 20 2
-BA02 480 0.55 (0.75) 20 3R2-A 12 2
-BA03 480 0.75 (1) 30 3R2-A 12 2
-BA04 480 1.5 (2) 50 3R4-B 6.5 4
-BA06 480 2.2 (3) 75 3R8-B 3 8
-BA10 480 3.7 (5) 100 3R18-B 1.5 18
Z
drive
=
V
line-line
3 * I
input-rating
480V
3 * 2.7
= = 102.6 Ohms
Z
xfmr
=
(V
line-line
)
2
VA
480
2
50,000
* % Impedance =
* 0.05 = 0.2304 Ohms
Z
xfmr
Z
drive
0.2304
102.6
= 0.00224 = 0.22%=