Electrical Connection Values; Electrical Data Without Built-In Transmitter Or Digital Display - WIKA TR25 Mode D'emploi

5. Commissioning, operation
The assembly of the thermowells or measuring instruments to the vessel/pipeline
■
should be carried out so that it is permanently technically sealed.
Electrostatic discharges of the thermowells or measuring instruments when grounding
■
the vessel or pipeline should be eliminated.

5.2 Electrical connection values

5.2.1 Electrical data without built-in transmitter or digital display

For group II instruments (potentially explosive gas atmospheres)
connection values apply:
U = DC 30 V
i
I = 550 mA
i
P (at the sensor ) = 1.5 W
1)
i
For group II instruments (potentially explosive dust atmospheres), the following maximum
connection values apply:
U
= DC 30 V
i
I = 550 mA
i
P (at the sensor ) = For values, see "Table 2" (column 2), chapter 3.7 "Ex marking"
2)
i
The internal inductance (L
Sensor circuit in Ex ia or ib, IIC intrinsic safety ignition protection
Only for connection to intrinsically safe circuits with the following maximum output values
for group II instruments (potentially explosive gas atmospheres):
U = DC 30 V
o
I = 550 mA
o
P = 1.5 W
o
For group II instruments (potentially explosive dust atmospheres), the following maximum
output values apply to their connection to intrinsically safe circuits:
U = DC 30 V
o
I = 550 mA
o
P = For values, see "Table 2" (column 2), chapter 3.7 "Ex marking"
o
1) The permissible power to the sensor depends on the temperature of the medium T
and the thermal resistance R
Calculation examples see chapter 8 "Calculation examples for self-heating of the pipe body at the sensor
mounting point".
2) The permissible power to the sensor depends on the temperature of the medium T
permissible surface temperature and the thermal resistance R
from "Table 2" (column 2), see chapter 3.7 "Ex marking".
3) Use in methane atmospheres
Owing to the higher minimum ignition energy of methane, the instruments can also be used where
methane causes a potentially explosive gas atmosphere. The instrument can optionally be marked with IIC
+ CH .
4
WIKA operating instructions model TR25 (Ex i)
) and capacitance (C
i
, but shall not be more than 1.5 W.
th
, the following maximum
3)
) of the TR25 are negligibly small.
i
, but shall not be more than the values
th
, the temperature class
M
, the maximum
M
17
EN