Monarch Instrument DC 2000 - Manual (Page 25)

Page 2-7
Chapter 2 Installation and Wiring
The Recorder accepts up to six direct inputs. Input connection is via plug in screw terminal connectors on the
rear panel. Inputs can be mixed in any combination of thermocouple, RTD, milliamps, millivolts, volts or contact
inputs. There is a common ground lug marked with a
for connection of signal cable shields or screens.
Read the following procedures prior to connecting inputs to the terminals.
WARNING: Ensure the power is off before connecting signal inputs to the unit.
The plug in screw terminal connectors are of the clamping screw variety, putting even pressure on the signal
wire. It is therefore not necessary to terminate the wires with lugs, however you may do so if you wish. The
maximum gauge wire that can be accommodated is 14 AWG or 2.5 mm². You will need a small screwdriver and
a pair of wire cutters and strippers. The use of shielded twisted lead wire is recommended to minimize electro-
magnetically induced noise.
WARNING: All unused inputs must have all contacts commoned togther.
CAUTION: Never run signal and power or control wiring together in the same conduit. This is to
prevent possible recording error due to induced signals between lines. Route signal
wires away from power wires at the rear panel.
NOTE: Ground cable shields at one end only to eliminate the possibility of interference due to
ground loop currents. When grounded transducers are used, the shield should be grounded
at the sensor end only.
Figure 2-7 Thermocouple, RTD and Linear Inputs
2.3.3.1 Thermocouple Inputs
Thermocouple input connections are made as shown in Figure 2-7 T/Cs. Note that a link must be installed
between the “-” terminal and “C” terminal.
2.3.3.2 Resistance Temperature Detector (RTD) Inputs
Two, three or four wire RTDs may be used for connection with cable compensation of ±50 ohms. Refer to
Figure 2-7 and manufacturing specifications.
2.3.3.3 Linear Inputs
Current inputs: 4-20 milliamps, 0-20 milliamps and 10-50 milliamps, using an external 50 ohm shunt.
Voltage inputs: ±150 millivolts, ±1.25 volts, ±2.5 volts, ±12.5 volts, ±25 volts and normally open/closed
contact inputs. Note that a link must be installed between the “-” terminal and “C” terminal. Refer to Figure
2-7 for details.