Vibrations; Measurement Procedures And Operational Conditions - ABB AMA Manual

7.4.3 Vibrations

7.4.3.1 Measurement procedures and operational conditions

3BFP 000 063 R0101 REV D
• Loose fastenings or anchor bolts, see Chapter 3 Installation and Alignment
• Rotor imbalance
• Coupling.
The following instructions are part of the following two ISO standards: ISO 10816-3:1998
Mechanical vibration - Evaluation of machine vibration by measurements on non-rotating parts:
Part 3: Industrial machines with nominal power above 15 kW and nominal speeds between 120
r/min and 15 000 r/min when measured in situ and ISO 8528-9:1995 Reciprocating internal
combustion engine driven alternating current generating sets: Part 9: Measurement and
evaluation of mechanical vibrations.
Measurement equipment
The measurement equipment shall be capable of measuring broad-band r.m.s. vibration with flat
response over a frequency range of at least 10 Hz to 1 000 Hz, in accordance with the
requirements of ISO 2954. Depending on the vibration criteria, this may require measurements
of displacement or velocity or combinations of these (see ISO 10816-1). However, for machines
with speeds approaching or below 600 r/min, the lower limit of the flat response frequency
range shall not be greater than 2 Hz.
Measurement locations
Measurements will usually be taken on exposed parts of the machine that are normally
accessible. Care shall be taken to ensure that measurements reasonably represent the vibration
of the bearing housing and do not include any local resonances or amplification. The locations
and directions of vibration measurements shall be such that they provide adequate sensitivity to
the machine dynamic forces. Typically, this will require two orthogonal radial measurement
locations on each bearing cap or pedestal, as shown in Figure 7-1 Measuring points. The
transducers may be placed at any angular position on the bearing housings or pedestals. Vertical
and horizontal directions are usually preferred for horizontally mounted machines. For vertical
or inclined machines, the location that gives the maximum vibration reading, usually in the
direction of the elastic axis, shall be one of those used. In some cases it may be recommended to
measure also in the axial direction. The specific locations and directions shall be recorded with
the measurement.
Manual for High Voltage Process Performance Motors
Maintenance - 53