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Connection to the EP network (grounding).
Electrostatic discharge (E.S.D.)
A screw-mounted grounding cable connection with max. 4 mm²
(AWG 11) cross-section through EP terminals is available on the
side of the housing.
The housing of the MicroTREK must be grounded.
Grounding resistance R < 1
Ω
The shielding of the signal cable should be grounded at the
control room.
The shielding doesn’t prevent a possible occurrence of
electromagnetic noises, therefore route the signal cable away
from power cables.
MicroTREK 2-wire non-Ex and Ex gauge
electronics are shielded up to 4 kV against E.S.D.
Note: E.S.D. cannot be solved by MicroTREK 2-wire
E.S.D. protection.
It is the customer’s responsibility to avoid E.S.D. by
grounding the tank, medium and probe installation.
D
ANGER OF INJURY
!
1.
The probe may receive an electrostatic discharge
during operation; ground the probe by pushing it
against the wall of the tank with an adequately
isolated tool before touching it to avoid any potential
risks electric shock.
2.
Ground the entry pipe and medium.
Non-hazardous-duty version
Power supply
Nominal voltage
24 V DC
Maximum voltage (U
input
):
35 V DC
Minimum voltage (U
input
):
Depending on the load impedance, see graph below.
Load impedance R
A
Loop resistance, R
loop
R
HART
+ R
cable
+ R
ammeter
Ohm
Minimum load impedance R
A
0 Ohm
Maximum load impedance R
A
750 Ohm
R
HART
resistance for HART
®
communication
250
Ohm (recommended)