Rockwell Automation 1336T Wiring and Grounding Guide, (PWM) AC Drives User Manual
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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%
=