Wiring Installation - YOKOGAWA Dpharp vigilantplant EJA Series Manual

5.3.1 Loop Configuration
Since the DPharp uses a two-wire transmission system,
signal wiring is also used as power wiring.
DC power is required for the transmitter loop. The
transmitter and distributor are connected as shown below.
For details of the power supply voltage and load
resistance, see Section 5.6.
(1) General-use Type and Flameproof Type
Hazardous Location
Transmitter terminal box
Figure 5.3 Connection between Transmitter and
Distributor
(2) Intrinsically Safe Type
For intrinsically safe type, a safety barrier must be
included in the loop.
Hazardous Location
Transmitter terminal box
+
–
Safety barrier
Figure 5.4 Connection between Transmitter and
Distributor

5.3.2 Wiring Installation

(1) General-use Type and Intrinsically Safe
Type
Make cable wiring using metallic conduit or waterproof
glands.
• Apply a non-hardening sealant to the terminal box
connection port and to the threads on the flexible
metal conduit for waterproofing.
Non-hazardous Location
Distributor
(Power supply unit)
Receiver
instrument
+
–
F0504.ai
Non-hazardous Location
Distributor
(Power supply unit)
Receiver
instrument
F0505.ai
<5. Wiring>
Flexible metal conduit
Wiring metal
conduit
Tee
Drain plug
Figure 5.5 Typical Wiring Using Flexible Metal
Conduit
(2) Flameproof Type
Wire cables through a flameproof packing adapter, or
using a flameproof metal conduit.
 Wiring cable through flameproof packing adapter.
• Apply a non-hardening sealant to the terminal box
connection port and to the threads on the flameproof
packing adapter for waterproofing.
Flameproof packing
adapter
Flexible metal conduit
Wiring metal
conduit
Tee
Drain plug
Figure 5.6 Typical Cable Wiring Using Flameproof
Packing Adapter
• Measure the cable outer diameter in two directions to
within 1 mm.
• Calculate the average of the two diameters, and use
packing with an internal diameter nearest to this value
(see Table 5.1).
Table 5.1 Flameproof Packings and Applicable
Cable Outer Diameters
Wiring Port Applicable
Optional
Thread Cable OD
Code
Diameter (mm)
G11
8 to 10
G 1/2
10.1 to 12
G12
• Mounting flameproof packing adapter body to conduit
connection (see Figure 5.7)
1) Screw the flameproof packing adapter into the
terminal box until the O-ring touches the wiring port
(at least 6 full turns), and firmly tighten the lock nut.
24
Apply a non-hardening
sealant to the threads for
waterproofing.
F0506.ai
Apply a non-hardening
sealant to the threads for
waterproofing.
F0507.ai
Identifying Part
Mark Number
16 8-10
G9601AM
16 10-12
IM 01C22A01-01E