ISO8529-9 Medir Vibraciones en Motores de Combustion Interna Generadores

7/29/2019 ISO8529-9 Medir Vibraciones en Motores de Combustion Interna Generadores

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BRITISH STANDARD BS 7698-9:1996

ISO 8528-9:1995

Reciprocating internalcombustion engine

driven alternating

current generating

sets

Part 9: Measurement and evaluation ofmechanical vibrations

ICS 29.160.40

opyright British Standards Institutionovided by IHS under license with BSI

Not for Resaleo reproduction or networking permitted without license from IHS

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BS 7698-9:1996

This British Standard, havingbeen prepared under thedirection of the EngineeringSector Board, was publishedunder the authority of theStandards Board and comesinto effect on15 July 1996

BSI 11-1998

The following BSI referencesrelate to the work on this

standard:Committee reference MCE/14Draft for comment 93/707619 DC

ISBN 0 580 25999 4

Committees responsible for thisBritish Standard

The preparation of this British Standard was entrusted to Technical

Committee MCE/14, Reciprocating internal combustion engines, upon whichthe following bodies were represented:

Agricultural Engineers Association

British Industrial Truck Association

Health and Safety Executive

Society of Motor Manufacturers and Traders

Co-opted members

Amendments issued since publication

Amd. No. Date Comments



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Contents

Page

Committees responsible Inside front cover

National foreword ii1 Scope 1

2 Normative references 1

3 Definitions 1

4 Symbols and abbreviations 1

5 Regulations and additional requirements 1

6 Measured values 2

7 Measuring devices 2

8 Location of measuring points and direction of measurements 2

9 Operating conditions during measurement 3

10 Evaluation of results 4

11 Test report 4Annex A (informative) Typical generating set configurations 5

Annex B (informative) Remarks on the assessment of vibrationsof the generating set 6

Annex C (informative) Vibration values 7

Annex D (informative) Measuring report 9

Annex E (informative) Bibliography 12

Figure 1 Arrangement of measuring points 3

Figure A.1 Engine and generator rigidly mounted 5

Figure A.2 Engine resiliently mounted, generator rigidlymounted, flexible coupling 5

Figure A.3 Engine and generator rigidly mounted on resilientlymounted base frame 5

Figure A.4 Engine resiliently mounted, generator rigidly mounted onresiliently mounted base frame, flexible coupling 5

Figure A.5 Assembly with flange housing and resilient mountingon the engine and generator 5

Figure A.6 Assembly with flange housing and resilient mountingof the engine 5

Figure C.1 Relationship between vibration velocity and vibrationfrequency 8

Table C.1 Rms values for vibration velocity, displacement andacceleration of RIC engine driven AC generating sets 7

List of references Inside back cover



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ii BSI 11-1998

National foreword

This Part of BS 7698 has been prepared by Technical Committee MCE/14 and isidentical with ISO 8528-9:1994 Reciprocating internal combustion engine driven

alternating current generating sets Part 9: Measurement and evaluation ofmechanical vibrations published by the International Organization forStandardization (ISO). ISO 8528-9 was prepared by ISO/TC 70, Internalcombustion engines.

A British Standard does not purport to include all the necessary provisions of acontract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunityfrom legal obligations.

Cross-references

International standard Corresponding British Standard

ISO 2041:1990 BS 3015:1991 Glossary of terms relating to mechanical

vibration and shock

(Identical)

ISO 5348:1987 BS 7129:1989 Recommendations for mechanical

mounting of accelerometers for measuring mechanical

vibration and shock

(Identical)

ISO 8528-5:1993 BS 7698 Reciprocating internal combustion engine

driven alternating current generating sets

Part 5:1993 Specification for generating sets

(Identical)

IEC 34-7:1992 BS EN 60034 Rotating electrical machines

Part 7:1993 Classification of types of constructions and

mounting arrangements (IM code)

(Identical)

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii,

pages 1 to 12, an inside back cover and a back cover.

This standard has been updated (see copyright date) and may have hadamendments incorporated. This will be indicated in the amendment table onthe inside front cover.



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1 Scope

This part of ISO 8528 describes a procedure for

measuring and evaluating the external mechanicalvibration behaviour of generating sets at themeasuring points stated in that InternationalStandard.

It applies to RIC engine driven AC generating setsfor fixed and mobile installations with rigid and/orresilient mountings. It is applicable for land andmarine use, excluding generating sets used onaircraft or those used to propel land vehicles andlocomotives.

For some specific applications (essential hospitalsupplies, high rise buildings, etc.) supplementary

requirements may be necessary. The provisions ofthis part of ISO 8528 should be regarded as a basis.

For generating sets driven by otherreciprocating-type prime movers (e.g. sewage gasengines, steam engines), the provisions of this partof ISO 8528 should be regarded as a basis.

2 Normative references

The following standards contain provisions which,through reference in this text, constitute provisionsof this part of ISO 8528. At the time of publication,the editions indicated were valid. All standards are

subject to revision, and parties to agreements basedon this part of ISO 8528 are encouraged toinvestigate the possibility of applying the mostrecent editions of the standards indicated below.Members of IEC and ISO maintain registers ofcurrently valid International Standards.

ISO 2041:1990, Vibration and shock Vocabulary.

ISO 5348:1987, Mechanical vibration and shock Mechanical mounting of accelerometers.

ISO 8528-5:1993, Reciprocating internal combustionengine driven alternating current generating sets Part 5: Generating sets.

IEC 34-7:1992, Rotating electrical machines Part 7: Classification of types of constructions andmounting arrangements (IM Code).

3 Definitions

For the purposes of this part of ISO 8528, thedefinitions given in ISO 2041 and the followingdefinition apply.

3.1vibration severity

a generic term that designates a value or set ofvalues, such as a maximum value, average value or

rms value, or other parameter that is descriptive ofthe vibration

NOTE 1 It may refer to instantaneous values or average values.

NOTE 2 ISO 2041 includes two notes in the definition. Thesenotes do not apply in this part of ISO 8528.

4 Symbols and abbreviations

For the purposes of this part of ISO 8528 thefollowing symbols apply.

The following subscripts are used in conjunctionwith the vibration quantities v, s and a.

The following abbreviation is used.

5 Regulations and additionalrequirements

5.1 For a.c. generating sets used on board ships andoffshore installations which have to comply withrules of a classification society, the additionalrequirements of the classification society shall beobserved. The classification society shall be statedby the customer prior to placing the order.

For a.c. generating sets in unclassed equipment,such additional requirements are in each case

subject to agreement between the manufacturer andcustomer.

a Acceleration

Peak value of acceleration

f Frequency

s Displacement

Peak value of displacement

t Time

v Velocity

Peak value of velocity

x Axial co-ordinate

y Transverse co-ordinate

z Vertical co-ordinate

v Angular velocity

rms Value of vibration quantity

x Measured value of vibration quantity

in the axial direction

y Measured value of vibration quantity

in the transverse direction

z Measured value of vibration quantity

in the vertical direction

1, 2 ...n Progressive values

IMB Type or construction and mounting

arrangement of generators according

to IEC 34-7

s

v



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5.2 If special requirements from regulations of anyother authority, e.g. inspecting and/or legislative

authorities, have to be met, the authority shall bestated by the customer prior to placing the order.

Any further additional requirements shall besubject to agreement between the manufacturer andcustomer.

6 Measured values

Acceleration, velocity and displacement aremeasured variables for the vibrations(see clause 10).

In the general case of any vibration over timeinterval t1 to t2, the rms velocity is given by

In the particular case of sinusoidal vibration therms velocity is given by

If the vibration characteristics are analysed and if

for angular frequencies v1, v2, ..., vn, the vibrationvelocities , , ......, , are available, then thefollowing relationships can be used to determine therms velocity:

NOTE 3 For acceleration and displacement rms values arecalculated in the same manner.

7 Measuring devices

The measuring system shall provide the rms values

of displacement, velocity and acceleration with anaccuracy of 10 % over the range 10 Hz to 1 000 Hzand an accuracy of % over the range 2 Hz to10 Hz. These values may be obtained from a singlesensor whose signal is either integrated ordifferentiated, depending on the outcome of themeasuring device, to derive the quantities notdirectly measured, provided the accuracy of themeasuring system is not adversely affected.

NOTE 4 The accuracy of measurement is also affected by themethod of connection between the transducer and the objectbeing measured. Both the frequency response and the measuredvibration are affected by the method of attaching the transducer.

It is especially important to maintain good attachment betweenthe transducer and the point on the generating set beingmeasured when vibration levels are high.

Refer to ISO 5348 for guidance on the mounting ofaccelerometers.

8 Location of measuring points anddirection of measurements

Figure 1 shows the recommended points of vibrationmeasurement in generating sets. The specificationsapply as appropriate for other types of design. Ifpossible, measurements shall be taken at thesepoints in the three main directions, defined by x,y

and z.Figure 1 shows the approximate positions of themeasuring points which have to be located on thesolid engine block and on solid areas of thegenerator frame in order to avoid measuring localstructural vibrations.

If experience with similar generating sets hasshown at which points the maximum vibrationseverity is to be expected, not all the points givenin Figure 1 need necessarily be measured.

9 Operating conditions during

measurementThe measurements shall be taken with thegenerating set at its operating temperature andrated frequency, at both zero power and ratedpower. If the rated power of the generating set is notattainable, it should be tested at the maximumpower that can be attained.

...(1)

...(2)

...(3)

...(4)

vrms

v2

dtt1

t2

t2 t1

---------------------=

vrmssv

2-------

v

2-------

a

v---

1

2-------= = =

v1 v2 vn

vrmsv1

2 v22 ... vn

2+ + +

2-------------------------------------------------=

vrms v rms12 v rms2

2 ... vrmsn2+ + +=

+ 10 20



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Figure 1 Arrangement of measuring points



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10 Evaluation of results

The main excitation frequencies of the RIC engine

itself are found in the range 2 Hz to 300 Hz.However, when considering the overall generatingset structure and components, a range of 2 Hz to1 000 Hz is required to evaluate the vibration.

Additional testing may be necessary to ensure thatno local structural resonances contribute to themeasurement result.

Assessment of the potential effects of vibration aremade by reference to Table C.1 which gives rmsvalues of vibration displacement, velocity andacceleration. These values can be used as guidelinesfor evaluating the measured vibration levels.

Experience has shown that with a standard designof generating set structure and components,damage would not be expected if vibration levelsremain below value 1.

If the vibration levels fall between values 1 and 2,assessment of the generating set structure and

components may be required along with anagreement between the generating setmanufacturer and the component supplier in orderto ensure reliable operation.

In some cases vibration levels can be above value 2but only if individual special designs of generatingset structure and components are applied.

In all cases the generating set manufacturerremains responsible for the compatibility with eachother of the generating set components(see ISO 8528-5:1993, 15.10).

11 Test report

The indicated measurement results shall includethe main data of the generating set and themeasuring equipment used. These data are to berecorded using annex D.



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Annex A (informative)Typical generating set configurations

There are a number of possibilities for the assemblyof a reciprocating internal combustion engine and agenerator. Figure A.1 to Figure A.6 show examplesof typical configurations.

Figure A.1 Engine and generator rigidlymounted

Figure A.2 Engine resiliently mounted,generator rigidly mounted, flexible coupling

Figure A.3 Engine and generator rigidlymounted on resiliently mounted base frame

Figure A.4 Engine resiliently mounted,generator rigidly mounted on resiliently

mounted base frame, flexible coupling

Figure A.5 Assembly with flange housingand resilient mounting on the engine and

generator

Figure A.6 Assembly with flange housingand resilient mounting of the engine



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Annex B (informative)Remarks on the assessment of

vibrations of the generating set

It has been found that generators operating ingenerating sets suffer higher values of vibrationseverity compared with those runningindependently.

Typical features of RIC engines are the oscillatingmasses, torque fluctuation and pulsating forces inthe associated pipe-work. All these features exertconsiderable alternating forces on the mainsupports and give rise to high vibration amplitudeson the main frame. The vibration amplitudes aregenerally higher than those for rotating machinery,

but since they are largely influenced by the designfeatures of the generating sets, they tend to remainmore constant over the life of the RIC engine thanthey do for rotating machinery.

The vibration values determined by using this partof ISO 8528 allow us to make a general statement onthe vibrational behaviour of the generating set anda general assessment of the running behaviour andthe vibration interactions of the total set. However,the determined vibration values do not allow us tomake a statement on the mechanical stresses offixed or moving parts of the generating sets.

Neither do the determined values of vibrationseverity allow us to make a statement of the

torsional and linear vibrational behaviour of theshaft system.

Even if accurate assessment of mechanical stressesin the generating set by using vibrationmeasurement is not possible, experience has shownthat the vibration level above which important partsof the generating set are mechanically damaged byundue vibration stress is usually significantlyhigher than the level which is accepted as usualfrom experience with similar generating sets.

However, if the above usual ranges are exceeded,damage to additional attachments and connectingparts of the generating set, as well as to governing

and monitoring devices, etc., may occur.

The sensitivity of these components depends ontheir design and how they are mounted. Thus, insome individual cases, it may be difficult to avoidproblems even when the assessment value lies inthe usual range. Such problems have to berectified by specific local measures on thegenerating set (e.g. by elimination of mountedcomponent resonances).



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7

Annex C (informative)Vibration values

Table C.1 Rms values for vibration velocity, displacement and acceleration of RIC engine driven AC generating sets(see clause 10)

Declared

engine speed

Rated power output of the

generating setVibration displacement

a, srms

Vibration velocity,vrms Vibration accelerationa

, arms

(cos w = 0,8)RIC engine

bc

Generatorb

RIC enginebc

Generatorb

RIC engineb

c

Generatorb

value 1 value 2 value 1 value 2 value 1 value 2

min1 kVA kW mm mm mm mm/s mm/s mm/s m/s2 m/s2 m/s2

> 2 000 but

< 3 600

< 15

(1-cylinderengine)

< 12

(1-cylinderengine)

1,11 1,27 70 80 44 50

< 50 < 40 0,8 0,95 50 60 31 38

>50 > 40 0,64d 0,8d 40d 50d 25d 31d

> 1 300 but

< 2 000

< 10 < 8

> 10 but

< 50

> 8 but

< 40 0,64 40 25

> 50 but

< 125

> 40 but

< 100 0,4 0,48 25 30 16 19

> 125 but

< 250

> 100 but

< 2000,72 0,4 0,48 45 25 30 28 16 19

> 250 > 200 0,72 0,32 0,45 45 20 28 28 13 18

> 720 but

< 1 300

> 250 but

< 1 250

> 200 but

< 1 000 0,720,32 0,39

4520 24

28

13 15

> 1 250 > 1 000 0,29 0,35 18 22 11 14

< 720 > 1 250 > 1 000 0,720,24

(0,16)e

0,32

(0,24)e45

15

(10)e

20

(15)e28

9,5

(6,5)e

13

(9,5)eNOTE The relationship between vibration velocity and vibration frequency is shown in Figure C.1.

aThe values ofsrms and arms are determined from the following equations by using the values given in the table for vrms.

srms = 0,0159 vrms

arms = 0,628 vrms

bIn the case of flange housing coupled generating sets the values measured at point 5 [see Figure 1 a)] shall meet the values for generators.

cThe stated values for RIC engines are applicable for engines with power outputs of more than 100 kW. For smaller engines with power outputs below 100 kW, no typical values

exist.d

These values are subject to agreement between the manufacturer and customer.e

The values given in parentheses are applied to generators mounted on solid concrete foundations. In these cases the axial measurement for points 7 and 8 in Figure 1 a) and b)shall be 50 % of the values given in parentheses.

right British Standards Institution

ded by IHS under license with BSINot for Resaleproduction or networking permitted without license from IHS

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Figure C.1 Relationship between vibration velocity and vibration frequency



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Annex D (informative)Measuring report

D.1 General data

Data of the RIC engine and generator to be measured

D.2 Data of configuration

Foundation drawing

No.: ......................................................

Company responsible: .............................Types of configuration

Company responsible for the measurement: Customer/User:

Report No.: Place of measurement:

Date: Operator:

RIC engine Generator

Manufacturer

Type

Manufacturing No.

Declared or rated power ..... kW ....kVA cos w = .......

Declared or rated speed

Declared or rated frequency ...... min1 ......min1 ... Hz

Construction design In-line engine IMB 20a IMB 520

V-engine IMB 16 Others: ......

IMB 3 ............

Number of Cylinders: ...... Bearings: ......

Operating system Two-stroke Synchronous

Four-stroke Asynchronous

Coupling arrangement Flexible plate coupling

Direct coupling

Elastic coupling

aAbbreviation for type of construction and mounting of generators according to IEC 34-7, code i.

Engine Generator FoundationBase frame

(if applicable)Flange housing

rigid rigid rigid rigid yes

resilient resilient resilient resilient no



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D.3 Measuring positions

The measuring positions and their numbering conform to those shown above. Additional measuringpositions should be numbered continually and must be marked on a drawing. It is recommended that allmeasuring positions be inserted in a detailed drawing.

D.4 Measurement results

Data records, diagrams and spectra, when applicable and required, must be attached.Measurement equipment

Particulars of measuring equipment

Component Manufacturer Type Remarks

Sensor

Measuring indicator set

Recording instruments

Calibration apparatus

NOTE Terms are according to ISO 2954.

Mechanical connection screwed hand held cemented magnetic

Measured value displacement velocity acceleration

Recorded value displacement velocity acceleration

Measuring range amplitude: ...... frequency: ......

Frequency analyser/filter linear range: .... pass-band: ......

Data for evaluation of measuring records (e.g. amplification, rate of feed):

Remarks:



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Measurement results

Power: ................................................. kW Ambient temperature: .......................................... C

Speed: ................................................. min1 Type of fuel: .............................................................

Measuring

point No.rms overall values (2 Hz to 300 Hz)

a Remarks

Direction of measurement

axial (x) transverse (y) vertical (z)

s

mm

v

mm/s

a

m/s2s

mm

v

mm/s

a

m/s2s

mm

v

mm/s

a

m/s2

a Either measured or calculated.



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List of references

See national foreword.



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ISO8529-9 Medir Vibraciones en Motores de Combustion Interna Generadores