Watlow MLS-PM, User Manual

Page: 54 / 144

Installation
MLS User’s Guide 41
Current Inputs
To install current (milliamp) inputs, place resistors in the input section
which convert the milliamp input into a voltage. (You can get different
current input ranges if you select different resistor values.) The input
connections for these inputs are the same as the input connections for
voltage inputs.
Voltage Inputs
Connect the + side of the voltage input to the A+ terminal. Connect the -
side of the input to the A- terminal. The voltage input range is -10 to 60
mV. Scale signals larger than 60 mV with a scaling resistor which makes
full scale input 60 mV.
The next figure shows two resistors. RA and RB are not loaded. RC is
the voltage reducing or current limiting resistor, and RD is the 60 mV
full scale dropping resistor. RD is normally less than 500 ohms, and it
should never exceed 1000 ohms.
Unused Inputs
Set the input type for unused inputs to "SKIP" to avoid the default T/C
break alarms.
Red
Black
100 Ohm RTD
IN +
IN
–
Analog Common
Black
Rear Terminal Block
Connections
RD
IN +
IN
–
To
RC
Circuitry