Micromod Micro-DCI: 53IT5100A Indicator/Totalizer User Manual
Page 24
2.4.2.1 POWER INPUT (AS SPECIFIED)
2.4.2.1.1 DC Power
Reference Figure 2-4 and connect the remote 24 V dc power supply to the instrument as follows:
1.
Connect (+) input line, via remote SPST switch, to terminal L1.
2.
Connect (-) input line to the system bus bar. The bus bar should be connected to a
good earth ground (#8 AWG wire is recommended). Individual wires should be run
from the controller Power Common (PC ) and Signal Common (SC ) terminals to the
bus bar. The chassis should be grounded by connecting terminal G to earth ground.
NOTE
Use of a common bus bar is recommended to minimize potential voltage
differences that may occur as the result of ground current loops, e.g.,
potential difference between separate signal grounds, power grounds,
etc.
2.4.2.1.2 AC Power
Reference Figure 2-4 and connect the specified line service (110-120, 220-240 V ac, 50 or 60 Hz)
to the instrument as follows:
1.
Connect the phase or hot line L, via a remote power disconnect switch or circuit
breaker, to terminal L1.
2.
Connect the neutral line N to terminal L2 for 110-120 V ac. Connect the neutral line N
to terminal L3 for 220-240 V ac.
3.
Connect Power Common to a good earth ground (#12 AWG wire is recommended).
4.
The instrument case should be grounded by connecting terminal G to earth ground at
the source of supply (green/green-yellow ground).
All supply connections include surge protection rated at 275 V ac normal mode.
NOTE
To minimize possible interference, ac power wiring should be routed
away from signal wiring.
2.4.2.2 CURRENT/VOLTAGE INPUT TO ANI0 THROUGH ANI3
When the input signal is from a 4-20 mA current transmitter, a precision 250 ohms (+/-0.1%) resis-
tor is required. (The resistor tolerance is critical, as the resistor is used to accurately convert the
current signal from the transmitter, which is typically 4-20 mA, to a specified analog input voltage
of 1 to 5 V dc). The back of the rear terminal board has the appropriate resistors (R1 and R2, re-
spectively ) for ANI0 and ANI1. Resistor for ANI2 and ANI3 are not supplied and must be installed
as shown in the upper left corner of Figure 2-4. If the input signal is already a voltage signal, its
corresponding resistor should be removed.
53IT5100 Indicator/Totalizer
2-6