19
Measurement of impeller rotary speed
Measurement of manual rotary speed
A calibrated rev counter is required for the manual measurement of the rotary
speed of the impeller or the transmission shaft (with a mobile instrument).
Check that the detected value of the number of revs (rpm) does not differ by more
or less than 5% of the nominal speed for which the fan was designed.
3000 hours - (30 mins.) - Measurement of the rotary speed with a mobile
instrument
Continuous measurement of the rotary speed
The fan must be equipped with a rotation sensor (provided with certain mod-
els) for the continuous measurement of the rotary speed of the impeller or the
transmission shaft.
For the details concerning the operation and wiring of the sensor, refer to the
manual of the sensor.
The user must verify the reading of the shaft rotary signal when the fan starts in
normal operating conditions so as to define the operating threshold.
A deviation of +/- 5% from the determined threshold value must therefore be
considered abnormal.
The user must consider an appropriate transient (brief pulse) when the motor is
started/stopped for the deviation from the nominal number of revs.
In the case of use with an inverter, the number of revs of the impeller or the shaft
must be verified in relation to the number of revs of the motor each time it is used.
24 hours continuous - (0) - Measurement of the rotary speed with in-
stalled probe
Measurement of earth resistance
The measurement of the earth resistance of the fan must be carried out by meas-
uring the resistance between the reference earth point of the user with the various
metal parts of the fan, after making sure that the earth connection was made.
Take the measurements on the chair, on the motor, on the auger, on the impel-
ler and any other metal parts of the fan according to its construction, such as:
shutters, transmission shaft and protection nets.
Pay attention to reading problems in the case of a direct measurement on painted
parts - check the electrical continuity on the screws connected to it.
Applying a tension of at least
12 Volt
you must measure a resistance lower than
or equal to
100 Ohm
.
3000 hours - (30 mins.) - Measurement of the earth resistance
Visual inspection
1000 hours - (30 mins.) - Visual inspection with the fan stationary and
running
M
aintenance
3,000 h
1,000 h
3,000 h
24 h
Summary of Contents for CH Series
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