User Manual User Manual

Wiring 3-39
SMC-Flex Controller as a Bypass to
an AC Drive
By using the controller as shown in Figure 3.37, a soft start
characteristic can be provided in the event that an AC drive is non-
operational.
Note: A controlled acceleration can be achieved with this scheme,
but speed control is not available in the bypass mode.
Figure 3.37 Typical Application Diagram of a Bypass Contactor for an AC
Drive
M
3
-Phas
e
In
p
ut Powe
r
VFD Br
a
n
c
h
Prot
ec
tio
n
VFD
L1
/1
L
3/5
L2
/3
T1
/2
T
3/6
T2
/4
S
M
C
-Flex
C
ontrolle
r
AF
AF
I
C
I
C
O
.L
.
➀➀
➁
➁
➁
➁
➃
➁
➁
➂
➀ Mechanical interlock required
➁ Customer supplied
➂ Many VF drives are rated 150% FLA. Because the SMC-Flex controller can be used for 600% FLA startin
g
,
separate branch circuit protection may be required.
➃ Overload protection is included as a standard feature of the SMC-Flex controller.