Yokogawa DO202 2-Wire Dissolved Oxygen Analyzer - Manual (Page 36)

IM 12J05C01-01E
3-5 Installation and Wiring
Extension cable may be purchased in bulk quanti-
ties, cut to length. Then it is necessary to terminate
the cable as shown below.
Termination procedure for WF10 cable.
1. Slide 3 cm of heat shrink tube (9 x 1.5) over the
cable end to be terminated.
2. Strip 9 cm of the outer (black) insulating material,
taking care not to cut or damage internal cores.
Figure 3-9a.
3. Remove loose copper screening, and cut off the
cotton packing threads as short as possible.
4. Strip insulation from the last 3 cm of the brown,
and the white coaxial cores.
Figure 3-9b.
5. Extract the coaxial cores from the braid, and trim
off the black (low-noise) screening material as
short as possible.
6. Insulate the overall screen and drain wire (14) and
the 2 coaxial screens with suitable plastic tubing.
7. Strip and terminate all ends with suitable (crimp)
terminals and identify with numbers as shown.
Figure 3-9c.
8. Finally shrink the overall heat shrink tube into
position.
3 cm
heat shrink
9 cm
remove insulation
3 cm
cotton threads
11
12
14
15
16
13
Red
Black
Blue
White
Brown
3-3-6. Additional precautions for installations in
hazardous areas
Make sure that the total of capacitance and induct-
ances connected to the input terminals of the EXA
DO202S do not exceed the limits given in the certifi-
cate.
This sets a limit to the cable and extensions used.
– The intrinsic safe version of the DO202S
instrument can be mounted in Zone 1 (DO202S-B,
-N, -D).
– The sensors can be installed in Zone 0 or Zone 1
if a safety barrier according to the limits given in
the system certificate is used.
– Ensure that the total of capacitance and
inductances connected to the terminals of the
EXA DO202S do not exceed the limits given in the
certificate of the safety barrier or distributor.
– The cable used should preferably have a BLUE
colour or marking on the outside.
– Installation for (sensors in Zone 0 or 1):
Generally, the distributor with input/output isolation
has no external earth connection. If there is
an earth connection on the distributor and the
external connection of the transmitter is connected
to “protective” earth, the shield of the 2-wire cable
may NOT be connected to “protective” earth at the
distributor too.
3-3-7. Installation in:
Hazardous Area-Non-Incendive
The EXA DO202S-B, -N, -D may be installed in a
Category 3, Zone 2, Div.2 area without the use of
safety barriers. Maximum permissible supply voltage
31.5V.