Two-speed motors with primary current transformer, Primary circuit, Separately ventilated motors – Rockwell Automation 825 Smart Motor Manager User Manual User Manual
Page 149: Figure 9.9

Applications/Wiring 9-8
Publication 825-UM001B-EN-P January 2001
Two-Speed Motors with Primary Current Transformer
When a primary current transformer is used, two-speed motors of any rating can be
protected.
Primary Circuit
Figure 9.9 Two-Speed Application Utilizing Primary Current Transformer
Separately Ventilated Motors
Because they are cooled constantly, separately ventilated motors exhibit the same thermal
behavior when stationary as when running. Consequently, the cooling ratio must be set to 1.
LCD:
For setting the cooling ratio, refer to
Chapter 5
825-MCM
2 (20)
825-M
L1
L2
L3
L1
L2
L3
K2
K1
N
(-)
R
L
(+)
825-MST
Y41
Y42
24 V AC/DC
8 mA
100-M05
100-M05
(I)
(II)
K1
K2
... A / 1 (5) A
(I)
(II)
... A / 1 (5) A
M
3 ~
220...230V AC/DC: R = 27k
Ω
/ 5W
110...120V AC/DC: R = 12k
Ω
/ 4W
24V AC/DC R = 0
Ω
For setting the second rated current (speed II)
refer to
Chapter 5
Secondary circuit
COOL-CONST RATIO
1.00