6
Power Supply
The SMC20 is available in two AC
power input versions. One version
operates from standard 115 VAC, single
phase, 50 or 60 Hz, fused at 2 amperes.
The other operates from 230 VAC,
single phase, 50 or 60 Hz, fused at 2
amperes. The SMC20 is also available
with one DC power input version. It
operates from +24 VDC, +5% and is
fused at 1 ampere.
Power supply input voltages are model
code selectable.
Table 2–1 shows the three versions.
Figure 2–2 locates the power supply
connection on the SMC20 front panel.
Version
Input Voltage
Fuse
SMC20 –
115
90 to 125 VAC
2 amperes
SMC20 –
230
200 to 240 VAC
2 amperes
SMC20 –
24
24 VDC
"
5%
2 amperes
Table 2-1. Three SMC20 Versions
Figure 2-2. Power Supply Connections
CAUTION
DO
NOT
TURN
POWER
`ON'
until
you
have
completed
all
connections
to
the
SMC20.
To connect power, use the power supply
screw–type terminal on the upper left
corner of the SMC20 front panel.
Recommendation: Use 14 to 16 AWG
wire. Figure 2–3 shows the connection.
Figure 2-3. Power Wiring for the SMC20
NOTE: ‘GND’ refers to earth ground. It
is important for safety reasons and for
proper operation of the controller that the
external GND connection is made as
described.
The two ground wires tie to each other
internally. Connect one ground wire to
the machine frame, the other to the
power company ground.
When you complete the power supply
connection, go on to the common
system connections.
Common System Connections
Common system connections provide
for signals that affect the controller, but
are not axis specific. For example, the
V+ connection provides a voltage supply
for optically isolated DC input/output
signals. You can connect V+ to one of
two power supplies:
D
A 10 to 30 VDC, user provided power
supply.
D
The 24 VDC from the isolated DC
supply on the SMC20.
Table 2–2 lists the common system
connections and the signals they carry.
Figure 2–4 locates the common system
and the isolated DC supply connections
on the SMC20 front panel.
Signal
Function
ENBL
Enable
optically
isolated
input
. Must
be
'On'
for
servo
output
command
voltage
or
current
to
operate.
V+
(T wo
terminals
internally
conĆ
nected)
Provides
a
voltage
supply
for
optically
isolated
DC
I/O. You
can
connect
it
to
a
user-supplied
powĆ
er
source
(15
to
30
VDC)
or
to
the
24
VDC
isolated
DC
supply
on
the
SMC20.
Note:
The
isolated
supply
means
isolated
from
all
other
controller
grounds.
CPU
CPU
fault
optically
isolated
output
. A
HIGH
level
indicates
that
one
or
both
proĆ
cessors
are
not
runĆ
ning.
Normal
state
is
open
circuit.
COM
Common
for
V+
isolated
power
supply
.
Table 2-2. Common System
Connections
Figure 2-4. Common System
Connections
