NORD Drivesystems B2050 - Manual (Page 31)

4. Commissioning
www.nord.com B2050-GB-0613 -31-
4.6 Temperature measurement
The details of the ATEX temperature class or the maximum surface temperature are based on
normal installation conditions (see Section 3.7). Even small changes to the installation conditions
can have a significant effect on the temperature of the gear unit.
Danger!
On commissioning, a surface temperature measurement of the gear unit must be made
under maximum load.
(This does not apply to gear units which are labelled as temperature class T1 – T3 or a
maximum surface temperature of 200°C in the last line of the name plate.)
For the measurement, a normal temperature measuring device is required, with a measurement
range from 0°C to 130°C and a precision of at least ± 4°C and which enables the measurement
of the surface temperature and the temperature of the air. Temperature measurement
procedure:
1. Allow the gear unit to run at maximum speed under maximum load for approx. 4 hours.
2. After warming up, the temperature of surface of the gear unit housing Tgm must be
measured at several points in the area of the drive unit bearings, close to the temperature
label (see Section 3.16).
3. Measure the temperature of the air Tum in the immediate vicinity of the gear unit.
Danger!
The gear unit must be shut down and Getriebebau NORD must be consulted if any of
the following criteria do not apply:
 The measured air temperature Tum is within the permissible range stated on the name plate.
 The maximum measured temperature of the gear unit housing surface Tgm is below 121 C
and the temperature-resistant adhesive label has not turned black. (See Figure 4-3)
 The measured temperature of the surface of the gear unit housing plus the difference
between the highest permissible air temperature Tu stated on the name plate and the
measured air temperature must be at least 15°C lower than the maximum permissible
surface temperature, i.e.:
ATEX labelling: II 2G c T4 / II 3G T4 : Tgm + Tu – Tum < 135°C – 15°C
ATEX labelling: II 2D c Tmax / II 3D Tmax: Tgm + Tu – Tum < Tmax – 15°C
Tgm: measured temperature of the surface of the gear unit housing in °C
Tum: measured air temperature in °C
Tmax: maximum surface temperature according to gear unit name plate (ATEX labelling) in °C
Tu:
upper value of the permissible ambient temperature range according to the name plate in °C