Wiring The Chillgard Rt Unit; Analog Signal Output Wiring (Figure 2-5); Vdc - MSA Chillgard RT Instruction Manual

Wiring the Chillgard RT Unit

4. Route power wiring through one of the entries in the side of
the unit.
NOTE: Power wiring should be separated from relay wiring.
5. For single fuse 100/120 Volts AC power connection, connect the:
• power wire to L1
• neutral wire to ACN
• ground wire to
6. For double fuse 220/240 Volts AC power connection, connect
power wires to L1 and L2 and ground wire to

Analog Signal Output Wiring (FIGURE 2-5)

The Chillgard RT unit has two available analog outputs. Each analog
output is software-selectable between 10% or 100% of full scale:
• 4-20 mA, isolated, current sourcing
•

0-10 VDC

These voltage and current outputs are proportional to the displayed
refrigerant concentration. Connections are made to terminal strip J17
located on the lower left side of the main circuit board (FIGURE 2-5).
Analog output wiring should enter the unit through the hole provided on
the left side of the unit. The terminal portion of the connector can be
removed from the circuit board for easier connection. The maximum
wire size that these connectors can accept is Listed #12 AWG; the
maximum cable length is 500 feet (152 m).
It is suggested that Listed #18 AWG, twisted-pair wire be used. If
shielded wire is necessary, ground the shields of all cables at the
receiving end of the signal. Do not ground or connect the shields at the
Chillgard RT Monitor.
4-20 mA
The 4-20 mA output sources current to a separate return. Connections
are made to terminals 2 (I+) and 3 (RTN) on terminal strip J17.
1-10 VDC
The 0-10 VDC output sources voltage to 2 K ohms maximum load.
Connections are made to terminals 4 (V+) and 5 (COM) on terminal
strip J17.
terminal
terminal.
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