Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 31)

<2. WIRING AND INSTALLATION>
2-4
IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
CAUTION
When installing cable glands, hold cable glands and tighten cable gland nuts to a torque of 6
N•m. If cable glands, not gland nuts, are tightened, O-rings may be come out from the proper
positions.
l Adapter for conduit work
When protecting the cable with a conduit, use an adapter (option codes: /CB4, /CD4, or /CF4).
Set the adapter as shown in figure 2.5, instead of using the cable gland as shown in figure 2.4.
Adapter
49
(1.93")
G1/2 screw (/CB4), 1/2 NPT screw (/CD4)
M20x1.5 screw (/CF4)
Approx.
55(2.2")
Packing
Unit: mm(inch) Nut
F0204.ai
Figure2.5 Adapter for conduit work (option)
CAUTION
When using a cable conduit, use a flexible conduit to avoid stress on the conduit adapter.
The stress on the conduit adapter may damage the housing.
2.4 Wiring the power supply
First make sure that the power supply is in accordance with the given specifications.
Power Supply: Nominal 24 V DC loop powered system
One (1) Sensor module (1 input): 16 to 40V DC (for pH/ORP, SC and DO),
17 to 40V DC (for ISC), 21 to 40V DC (for SENCOM)
Two (2) Sensor modules (2 inputs): 22.8 to 40V DC (for pH/ORP, SC and DO)
Note: When the FLXA21 is used in the multi-drop mode of HART communication, the output signal is changed from 12.5 mA DC to
4 mA DC just after the power is turned on. Enough power supply for the instruments is to be provided.
250
600
1000
0 24.7 18
V - 11.5
0.022
R =
1295
1617 22.8 40 40
Voltage (V)
2-sensor measurement
Load resistance (Ω)
Digital Communication
Range (HART)
250
304
600
516
1000
0 24.7 18
V - 11.5
0.022
R =
1295
17 40 22.86 40
Except SENCOM
Voltage (V)
Load resistance (Ω)
Digital Communication
Range (HART)
18.2 21
Figure2.6 Supply Voltage and Load Resistance
Open the front panel and remove the wiring covers to make the terminal block accessible.