KMC Controls
Revision E
Installing the controller
Connecting outputs
8
4–20 mA inputs
To use a 4–20 current loop input, connect a 250 ohm resistor from an input to
ground. The resistor will convert the current input to a voltage which can be read by
the controller analog-to-digital converter. Set the pull-up switch to the
Off
position.
Ground terminals
Input ground terminals are located next to the input terminals. Up to two wires, size
14
–
22 AWG, can be clamped into each ground terminal. If more than two wires must
be joined at a common point, use an external terminal strip to accommodate the
additional wires.
Pulse inputs
Connect pulse inputs under the following conditions:
◆
If the pulse input is a passive input such as switch contacts, then place the
input pull-up in the
On
position.
◆
If the pulse is an active voltage (up to a maximum of +5 volts DC ), then place
the input pull-up jumper in the
Off
position.
Connecting
outputs
The BAC-7401 outputs are single-stage triacs designed to directly switch 24-volt ac
circuits.
Caution
When connecting loads to triacs, use only the terminal marked RTN associated
with each triac for the 24-volt ciruit.
Illustration 2-2 Output terminals
T4 R
TN T3
T2 R
TN T1
1
T4 R
TN T3
T2 R
TN T1
Triac 3 and 4
output and
return
Triac 1 and 2
output and
return
