WIKA TR30 - Handbuch (Seite 22)

14016442.01 06/2011 GB/D
22 WIKA operating instructions model TR30 per ATEX
GB
Version with output signal Pt100, model TR30-P
■ Sensor current loop
Voltage Ui DC 30 V
Current Ii 550 mA
Power Pi see table 2
Effective internal capacitance negligibly small
Effective internal inductance negligibly small
Ambient temperature: depending on the temperature class, either table 2 (for gas
ignition source) or table 3 (for dust ignition source) applies.
Table 2, model TR30-P-A (for gas)
Temperature
class
Power Pi Max. permissible temperature
at the sensor tip
Ambient temperature T
amb
T1 1500 mW 450 °C -20 °C ≤ T
amb
≤ 80 °C
T2 1500 mW 300 °C -20 °C ≤ T
amb
≤ 80 °C
T3 500 mW 200 °C -20 °C ≤ T
amb
≤ 80 °C
T4 250 mW 135 °C -20 °C ≤ T
amb
≤ 80 °C
T5 50 mW 100 °C -20 °C ≤ T
amb
≤ 75 °C
T6 50 mW 85 °C -20 °C ≤ T
amb
≤ 60 °C
When using a duplex measuring resistor (or two single measuring resistors), and operating
them simultaneously, the sum of the individual power values must not exceed the value of
the max. permissible power specified in table 2 or table 3.
Table 3, model TR30-P-B (for gas and dust)
Power Pi Ambient temperature T
a
Max. surface temperature T
750 mW -20 ... +40 °C T
a
max. + self-heating
650 mW -20 ... +70 °C T
a
max. + self-heating
550 mW -20 ... +100 °C T
a
max. + self-heating
The supplied power, Pi, is only realised at the sensor tip. The self-heating can, depending
on the design, be calculated with the following table:
Table 4
Installation type Thermal resistance Rth
For thermowell Ø 3 mm For thermowell Ø 6 mm
Without additional thermowell 110 K/W 75 K/W
Installed in a blind bore
(minimum wall thickness 5 mm)
22 K/W 16 K/W
Specific conditions for safe use: none
9. Safety-related instructions for Ex operation