4
FLEX I/O Terminal Base Units
Publication 1794-IN092E-EN-P - November 2009
Typical Wiring Guidelines
Terminal base units are rated at 10 A.
For Spring-clamp Terminal Base Units: 1794-TB3S, -TB3TS, -TB3GS, -TB32S,
-TB3SK, -TB3TSK, -TB3GSK
″
Insert a 2.54…3.05 mm (0.10…0.12 in.) wide-bladed screwdriver into the slot and lift up.
Insert wire, and remove screwdriver.
For Cage-clamp Terminal Base Units: 1794-TB2,
-TB3, -TB3K, -TB3T,-TB3TK, -TB3G, -TB3GK, -TB32
″
Tighten screws to 0.8 Nm (7 lb-in).
For Knifeswitch Cage-clamp Terminal Base Unit: 1794-TBKD
″
Tighten screws to 0.53 Nm (6 lb-in).
For NEMA Screw-clamp Terminal Base Units: 1794-TBN, -TBNK, -TBNF,
-TBNFK
″
Tighten screws to 1.02 Nm (9 lb-in).
Install or Change a Fuse in the 1794-TBNF or 1794-TBNFK Terminal Base
Unit
This terminal base unit has fuse holders for 5x20 mm fuses on each of the eight
even-numbered I/O terminals (0 through 14 - row B). To install or change a fuse:
1.
Press the fuse holder down toward the terminal strip.
2.
Remove the fuse from the fuse holder.
3.
Insert a known good 5x20 mm fuse into the fuse holder.
4.
Rotate the fuse holder back to vertical until it snaps into the locked
position.
The 1794-TBNF and 1794-TBNFK terminal base units are shipped with eight 5x20
mm, 1.6 A, 250V AC slow-blow fuses, one for each even-numbered terminal (0
through 14 on row B). These fuses are suitable for use with the 1794-OA8 AC
output module. Refer to the specific installation instructions for fusing
recommendations for your particular module.
Use the Knifeswitch Terminal Base
The knifeswitch terminal base has 16 individual mechanical-knifeswitch circuit
breakers (two for each channel). Each switch opens or closes one side (input/output
and return) for a channel.
1.
Place a small-bladed screwdriver into the slot of the knifeswitch of the I/O
point circuit that you wish to break.
2.
Rotate downward to open the circuit.
This opens the path of an individual circuit.
3.
To reestablish the circuit, rotate the knifeswitch back into the terminal base
unit until it snaps into place.
16
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
51
33
34
+V
COM
+V
COM
B
C
Even Numbered I/O Terminals 0 to 14
Odd Numbered I/O Terminals 1 to 15
(1794-TBN shown)
+V = Terminals C-34, C-51
COM (-V) = Terminals B-16, B-33
Wiring Connections for the 1794-TBN, 1794-TBNK, 1794-TBNF, 1794-TBNFK
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
16
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
34
Wiring Connections for the 1794-TB3T, -TB3TS
Inputs/Outputs
(1794-TB3T shown)
+V = Supply Out - Terminals C-50, C-51
Supply
In
Supply
Out
A
B
C
C
N3
CJC
+V
C
C
C
C
C
C
C
C
C
N2
N1
N0
N7
N6
N5
N4
+V
CJC
Chassis Ground
+V) = 24V dc Supply In - Terminals C-34, C-35
Channel Channel Channel Channel Channel Channel Channel Channel
0
1
2
3
4
5
6
7
+
--
+
--
+
--
+
--
+
--
+
--
+
--
+
--
C = -V dc common
-V = 24V dc Common Terminal B-16
-V = Terminal B-33
Wiring Connections for the 1794-TB3T, - TB3TK, -TB3TS, -TB3TSK
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
16
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
34
Inputs/Outputs
Common
-V (Common) = Terminals B-16, B-33, C-35 through C-50
+V (Voltage In) = Terminals C-34, C-51
-V
Voltage
In +V
Voltage
Out +V
B
C
Common
-V
Common
Wiring Connections for the 1794-TBKD
For daisy-chaining: Supply in - C-34 (+), B-16 (-)
Supply out - C-51 (+), B-33 (-)
CH0
CH2
CH3
CH4
CH5
CH6
CH7
CH1
CH0
RET
CH2
RET
CH3
RET
CH4
RET
CH5
RET
CH6
RET
CH7
RET
CH1
RET
Wiring Connections for the 1794-TBKD
Wiring when total current draw through base is less than 10 A.
Wiring when total current draw through base is greater than 10 A.
Modules in this configuration must be all analog or all digital.
Total current draw through any base must not be greater than 10 A.
Wiring when there is a mix of analog and digital modules.
24V dc
24V dc
24V dc
Digital Module
Digital Module
Digital Module
Thermocouple
or Analog Module
Use separate power supplies for analog and digital modules.
Press down to open.
