Pfeiffer Vacuum OKTA 2000 ATEX, Руководство по эксплуатации

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Evaluation of the vibration measurement
Regular vibration measurements ensure reliable evaluation of the condition of the pump, motor, and
bearing.
1. After commissioning, conduct vibration measurements every 2 weeks and evaluate the results.
– Keep to this interval for a period of at least 3 months until the vacuum pump has been "run
in."
2. Shorten the interval to weekly and daily measurements if there are anomalies in the trend.
3. Extend the vibration measurement interval to the periods stated in the applicable standards, or de-
fine suitable intervals that reflect the operating conditions.
Carrying out a bearing replacement
1. Carry out a bearing replacement in accordance with Maintenance Level 3 if significant changes
occur in the trend (significant rise or drop) in accordance with the guidelines VDI 3836 or
VDI 3832 during condition monitoring of the vacuum pump or the pump bearing.
2. Using your own experience of condition monitoring, define limit values that will initiate Mainte-
nance Level 3 for the vacuum pump in the event of changes in trend.
Carrying out an motor replacement
1. Carry out a motor replacement if significant changes occur in the trend for vibrations (significant
rise or drop) in accordance with standards DIN ISO 10816-1 or DIN ISO 10816-3 during condition
monitoring of the motor.
2. In accordance with your own experience of condition monitoring, define limit values that result in a
motor replacement in the event of a change in trend.
6.6.1 Monitor the operating condition
You must evaluate the vibrations in two relevant frequency ranges in accordance with the broadband
method:
● Frequency range A incorporates the significant mechanical and aerodynamic vibration stimula-
tions of the roots pump.
● Frequency range B takes into account the vibration stimulations through imbalance of the rotating
components.
Procedure
► Generate and evaluate a broadband root-mean-square-value for the sound velocity (v
eff
) when
evaluating the respective frequency ranges.
Frequency Frequency limits (ro-
tation speed)
Description
Frequency
range A
10 Hz – 1000 Hz Due to the permissible rotation speeds, only the range
between 10 and 1000 Hz is relevant
Frequency
range B
10 Hz – (2 × n) Hz Deviating from VDI 3836, the upper limit is derived
from twice the rotation frequency.
Tbl. 11: Evaluated frequency ranges
6.6.2 Monitoring the bearing condition
Evaluation of the pump bearing oscillations is based on the frequency-selective method (narrow band
method).
● A performance spectrum or envelope curve spectrum extracts the anti-friction bearing-specific or
characteristic frequencies (rollover frequencies, bearing damage frequencies).
● Evaluation of the amplitudes as characteristic values.
● Concentrating multiple lines of a characteristic frequency to a narrow band.
● Assessment of the root-mean-square-value of the vibration acceleration and / or the maximum
value amount of the vibration acceleration in a band.
Operation
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