Yokogawa EXA SC202 2-Wire Conductivity Transmitter/Analyzer - Manual (Page 38)

IM 12D08B02-01E
Installation and wiring 3-5
3-3-3. Installation in: Hazardous Area-Non-Incendive
The SC202S-N may be installed in a Category 3/ Zone 2/ Div.2 area without the use of safety barriers.
Maximum permissible supply voltage 31.5V.
3-4. Wiring of power supply
3-4-1. General precautions
Do not activate the power supply yet. First make sure that the DC-power supply is according to the spec-
ifications given.
DO NOT USE ALTERNATING CURRENT OR MAINS POWER SUPPLY! !
The cable leading to the distributor (power supply) or safety barrier transports power to and output sig-
nal from the transmitter. Use a two conductor shielded cable with a size of at least 1.25 mm 2 and an
outside diameter of 6 to 12 mm. The cable gland supplied with the instrument accepts these diameters.
The maximum length of the cable is 2000 metre, or 1500 metres when using the communications. This
ensures the minimum operating voltage for the instrument.
Grounding:
• If the transmitter is mounted on a grounded surface (e.g. a metal frame fixed in the soil) the shield of
the 2-wire cable may NOT be connected to ground at the distributor.
• If the transmitter is mounted on a non-conducting surface (e.g. a brick wall) it is recommended to
ground the shield of the 2-wire cable at the distributor end.
3-4-2. Connection of the power supply
The terminal strip is accessed as was described in section 3-2-1. Use the left-hand gland to insert the
supply/
output cable to the transmitter. Connect the supply to the terminals marked +, - and G as is indicated in
figures 3-11.
3-4-3. Switching the instrument on
After all connections are made and checked, the power can be switched on from the distributor. Observe
the correct activation of the instrument at the display. If for any reason the display does not indicate a
value, consult the trouble shooting section.
WARNING
mA
11
12
13
14
15
16 1 2
3
5
6
4
white
brown
green
yellow
grey
pink
Fig. 3-7. Connection diagrams