Fig. 27 – Hach-Lange EVITA OXY User Manual User 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.
