Hach-Lange EVITA OXY User Manual - Manual (Page 19)

17
The USC 7000 is able to communicate with up to
15 EVITA
® OXY transmitters using HART ® multidrop
protocol on only two wires.
Each transmitter should be connected in parallel
outside the USC connection box and only two wires
with shield mounted on the terminals in the USC
7000.
Digital input
Relay 1
Relay 2
Relay 3
Relay 4
Relay 5
I out 1
I out 2
I out 3
I out 4
USC 7000 and OXY 4100/4150 multidrop
Fig. 27
Shield
Black
Red
Important: The below mentioned warnings concern
both USC 5000, USC 6000 and USC 7000.
The HART communication terminals (84/85)
and the Digital Input terminals (77/78) of
the Universal Signal Converter must not be
connected to external voltage level above 30
V d.c.
The Relay terminals (40-49) of the Universal
Signal Converter must not be connected to
external voltage level exceeding 48 V d.c., 30
V rms or 42 V peak.
Protective conductor terminal. Required cable
min. AWG16 or 1.5 mm
2 Cu.
Field wiring installation of the Universal Signal
Converter must be in accordance with the
National Electrical Code.
Mains supply 100 to 240 V a.c. from building
installation (Overvoltage category II). A switch
or circuit-breaker (max. 15 A) shall be included
in the building installation. The switch/circuit-
breaker shall comply with relevant require-
ments of IEC 947-1 and 947-3. It must be in
close proximity to the equipment and within
easy reach of the operator, and it shall be
marked as the disconnecting device for the
equipment.
Note: Components like motors, pumps and
computers may cause high voltage potential
differences between the protective earth/
ground wire and the water in the tank, that
results in unstable readings. If this problem
occurs, mount an earthing electrode in the
tank to equalise the electrical potential of the
water to PE.
If the fl ow velocity in the tank is high, it may
cause a static potential locally. Is this the
case, mount the earthing electrode close to
the transmitter.