Commissioning, Operation - Wika Tr31-3 Betriebsanleitung

6. Commissioning, operation

6. Commissioning, operation
EN
6.1 Mounting
These resistance thermometers are designed for screw-fitting directly
into the process. The insertion length, along with the flow velocity and
viscosity of the process media, may reduce the max. loading on the
thermowell.
The case must be grounded against electromagnetic fields and
electrostatic discharge. It is not necessary to connect the case
separately to the equipotential bonding system, provided that it has a
fixed and secure contact to the metallic vessel, its components or pipes,
and that these are connected to the equipotential bonding system.
When there is a non-metallic contact with the vessel, or with its structural
components or piping, all projecting, electrically conducting thermometer
components in the hazardous area must be provided with equipotential
bonding.
22
WARNING!
Avoid putting any mechanical loading on the electrical
connections and on the cases. Connections must only be
opened once the instrument has been depressurised and
has cooled down.
Maximum permissible temperatures:
At case with transmitter: 85 °C (185 °F)
■
With directly connected cable: -20 ... +80 °C (-4 ... +176 °F)
■
Class A:
■
Without neck tube -30 ... +150 °C (-22 ... +302 °F)
With neck tube -30 ... +250 °C (-22 ... +482 °F)
Class B:
■
Without neck tube -50 ... +150 °C (-58 ... +302 °F)
With neck tube -50 ... +250 °C (-58 ... +482 °F)
1) Version with mineral-insulated sheathed cable can be used up to 300 °C (572 °F).
WIKA operating instructions models TR31-3, TR31-K (Ex i)
1)