ABB MD21 User Manual

03 . INSTALLATION AND WIRING 11
Digital inputs for various
functions
Digital inputs for various
functions
CT inputs
(lead-through)
CT inputs
(lead-through)
Thermistor
input
Thermistor
input
Interface for MDx
Interface for MDx
Communication ports
Communication ports
RCT inputs
RCT inputs
Relay output
Relay output
Ground safety
and surge
Ground safety
and surge
Voltage input
Voltage input
Power supply
Power supply
1 2 3 4 5 6 7 8 9 10 11 1
1 2 3 4 5 6 7 8 9 10 11 1
2
2
1 2 3 4 5 6 7 8 9 10 11 12 1
1 2 3 4 5 6 7 8 9 10 11 12 1
3
3
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1
6
6
X2
X2
X1
X1
X3
X3
X4
X4
L
L
T
T
Interfaces
Terminal blocks of M10x are located on the top of
the main unit for easy access. There are 3 sets of
I/O terminal blocks and 1 set of RJ11 connectors
as shown.
—
03 Top view terminal layout (24VDC)
—
04 Top view terminal layout (110VAC or 240VAC)

ABB MD21 Specifications

General

Brand	ABB
Model	MD21
Category	Control Unit
Language	English