ISO 9249:1989

I N TE R NAT I O NA L IS0
STANDARD 9249
First edition
1989-12-01
Earth-moving machinery - Engine test code -
Net power
Engins de terrassement - Code d'essai des moteurs - Puissance nette
Reference number
IS0 9249 : 1989 (E)

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IS0 9249 : 1989 (E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide federation of
national standards bodies (IS0 member bodies). The work of preparing International
Standards is normally carried out through IS0 technical committees. Each member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the IS0 Council. They are approved in accordance with IS0 procedures requiring at
least 75 % approval by the member bodies voting.
International Standard IS0 9249 was prepared by Technical Committee ISO/TC 127,
Earth-moving machinery.
Annexes A, B, C and D of this International Standard are for information only.
NOTE - IS0 1585, the terminology of which is based on IS0 2710 : 1978, ~eciprocati~gin~ern~/
combustion engines - Vocabdary, is also the basis for the following parallel documents:
IS0 2288 : 1979, Agricuiturai tractors and machines - Engine test code (bench test) - Net
power.
IS0 4106 : 1978, Road vehicles - Motorcycles - Engine test code - Net power.
IS0 4164 : 1978, Road vehicles - Mopeds - Engine test code - Net power.
O IS0 1989
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in
writing from the publisher.
International Organization for Standardization
Case postale 56 O CH-I21 1 Geneve 20 O Switzerland
Printed in Switzerland

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INTERNATIONAL STANDARD IS0 9249 : 1989 (E)
Earth-moving machinery - Engine test code - Net power
3.3 standard production equipment : Any equipment pro-
1 Scope
vided by the manufacturer for the particular engine application.
This International Standard specifies a method for testing
internal combustion engines intended for propulsion of earth-
4 Accuracy of measurements
moving machinery as defined in IS0 6165. It applies to evalu-
ation of performance with a view in particular to presenting
4.1 Torque
curves of power and specific fuel consumption at full load as a
* function of engine speed. The engines may be naturally
The dynamometer torque-measuring system shall give an ac-
aspirated or pressure-charged.
curacy within f 1 % in the range of scale values required for
the test. It shall be calibrated to take friction losses into
NOTE - This International Standard is in conformity with IS0 1585; it
account.
relates to tests on an engine capable of being fitted into earth-moving
machinery.
4.2 Engine rotational frequency
2 Normative references
Engine rotational frequency shall be measured preferably with a
revolution counter and an automatically synchronized
The following standards contain provisions which, through
chronometer (or counter timer). The accuracy of the measured
reference in this text, constitute provisions of this International
value shall be j, 0,5 %.
Standard. At the time of publication, the editions indicated
were valid. All standards are subject to revision, and parties to
4.3 Fuel consumption
agreements based on this International Standard are encouraged
to investigate the possibility of applying the most recent
Accuracy of fuel consumption measurements shall be f 1 %
IEC and IS0
editions of the standards listed below. Members of
overall for the apparatus used.
maintain registers of currently valid International Standards.
4.4 Fuel temperature
IS0 1585 : 1982, Road vehicles - Engine test code - Net
power.
Accuracy of fuel temperature measurements shall be to within
i 2 K (+ 2 OC).
e IS0 3173 : 1974, Road vehicles - Apparatus for measurement
of the opacity of exhaust gas from diesel engines operating
under steady state conditions.
4.5 Air temperature
IS0 6165 : 1987, Earth-moving machinery - Basic types -
The accuracy of this temperature measurement shall be i 2 K
Vocabulary.
(* 2OC).
4.6 Barometric pressure
3 Definitions
Barometric pressure shall be measured to f 100Pa ( f 1 mbar')).
For the purposes of this International Standard, the following
definitions apply.
4.7 Pressure in exhaust duct
3.1 net power : Power obtained on a test bed at the end of
Subject to footnote 2) to table 1, this pressure shall be
the crankshaft or its equivalent at the corresponding engine
measured to f 200 Pa ($: 2 mbarl)).
speed with the auxiliaries listed in table 1. If the power measure-
ment can be carried out only with the gear-box mounted, the
4.8 Pressure in intake duct
efficiency of the gear-box shall be taken into account.
Subject to footnote 1) to table 1, this pressure shall be
auxiliaries : Equipment and devices listed in table 1.
3.2 measured to f 50 Pa ( f 0,5 mbar')).
1 t 1 bar = IO5 Pa
1

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IS0 9249 : 1989 (E)
Table 1 - Installation of auxiliaries during test
Fitted for net power test
No. Auxiliaries
~
-
1 Intake system
Intake manifold
Crankcase emission control system
Air filter') Yes, standard production equipment
Intake silencer and duct workl'
Speed-limiting device"
Induction-heating device of intake manifold Yes, standard production equipment. If
2
possible, to be set in the most favourable
condition.
~~~
3 Exhaust system
Exhaust purifier
Manifold
Connecting pipes2)
Yes, standard production equipment
Siiencer2)
Tail pipe2)
I
Exhaust brake3)
Fuel suPOlV pump4) Yes, standard production equipment
4
__
5 Carburettor
Electronic control system, air-flow meter, etc. (if fitted) Yes, standard production equipment
Pressure reducer
Evaporator Equipment for gas engine
Mixer
6 Fuel injection equipment
Prefilter
Filter
Pump
High-pressure pipe Yes, standard production equipment
Injector
Air intake valve (if fittedP
Governor (if fitted)
J
1) The complete intake systems shall be fitted as provided for the intended application :
- where there is a risk of noticeable influence upon engine power;
- in case of two-stroke and spark-ignition engines;
- when the manufacturer requests that this should be done.
In other cases an equivalent system may be used and a check made to ascertain that intake pressure does not differ by more than I 100 Pa
( I 1 mbar) from the limit specified by the manufacturer for a clean air filter.
2) The complete exhaust system shall be fitted as provided for the intended application :
- where there is a risk of noticeable influence upon engine power;
- in case of two-stroke and spark-ignition engines;
- when the manufacturer requests that this should be done.
In other cases, an equivalent system may be installed providing pressure measurement at the outlet of the engine exhaust system does not differ
by more than I 1 O00 Pa if 10 mbar) from that specified by the manufacturer.
The outlet from the engine exhaust system is defined as a point 150 mm downstream from the termination of that part of the exhaust system
mounted on the engine.
3) If an exhaust brake is incorporated in the engine, the throttle valve shall be fixed in the fully open position.
4) The fuel feed pressure shall be adjusted, if necessary, to reproduce pressures existing in the particular engine application (particularly where a
fuel return system is used).
5) The air intake valve is the control valve for the pneumatic governor of the injection pump. The governor of the fuel injection equipment may
contain other devices which may affect the amount of fuel injected.
2

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IS0 9249 : 1989 (E)
Table 1 - (conchdedl
-
Fitted for net power test
No. Auxiliaries
Liquid cooling equipment61
Engine bonnet
Bonnet air outlet
Radiator
FanCl. 71
Yes, standard production equipment
Fan cowl
Water pump
Thermostat81
I
Air cooling
Cowl
Yes, standard production equipment
Fan or blower61r 71
} I
Auxiliary test bed fan Yes, if necessary
Temperature regulating device Yes, standard production equipment
9 Electrical e~uipmentgl Yes, standard production equipment
~ ~~
10 Pressure-charging equipment (if fitted)
Comprossor - driven either directly or indirectly by the engine
(supercharger), and/or by the exhaust gases (turbocharger)
intercooier10) Yes, standard production equipment
Coolant pump or fan (engine-driven)
Coolant flow control device (if fitted)
-
11 Anti-pollution devices Yes, standard production equipment
-
6) The radiator, fan, fan cowl, water pump and thermostat shall be located on the test bed in the same relative positions as those they will oc-
cupy on the machine. The cooling liquid circulation shall be operated by the engine water pump only.
Cooling of the liquid may be produced either by the engine radiator or by an external circuit, provided that the pressure loss of this circuit and the
pressure at the pump inlet remain substantially the same as those of the engine cooling system. The radiator shutter, if incorporated, shall be in the
open position.
Where the fan, radiator and cowl system cannot conveniently be fitted to the engine, the power absorbed by the fan when separately mounted in
its correct position in relation to the radiator and cowl (if used) shall be determined at the speeds corresponding to the engine speeds used for
measurement of the engine power either by calculation from standard characteristics or by practical tests. This power corrected to the standard
atmospheric condition defined in 6.2 should be deducted from the corrected power.
7) Where a disconnectable or progressive fan or blower is incorporated, the test shall be made with it disconnected or running at maximum slip,
as appropriate.
8) The thermostat may be fixed in the fully open position.
9) Minimum power of the generator : the power of the generator shall be limited to that necessary for the operation of accessories which are
indispensable for the operation of the engine. If the connection of a battery is necessary, a fully charged battery in good order shall be used.
IO) Charge-air-cooled engines shall be tested complete with charge-air cooling whether liquid- or air-cooled, but, if the engine manufacturer
prefers, a test bed system may replace the air-cooled cooler. In either case the measurement of power at each speed shall be made with the
pressure drop and temperature drop of the engine air across the charge-air cooler or test bed system the same as those specified by the manufac-
turer for the system on the complete machine.
fe
- power-steering pump;
5 Tests
- air-conditioning system.
5.1 Auxiliaries
Where accessories cannot be removed, the power absorbed by
5.1.1 Auxiliaries to be fitted
them in the unloaded condition may be determined and added
to the measured engine power.
During the test, auxiliaries necessary to make the engine accep-
table for service in the intended application (as listed in table 1)
shall be installed on the test bed as far as possible in the same 5.1.3 Compression-ignition engine starting
position as in the intended application.
auxiliaries
For auxiliaries used in the starting of compression-ignition
I 5.1.2 Auxiliaries to be removed
engines, the two following cases shall be considered:
I
I Certain machine accessories necessary only for operation of the
a) Electrical starting : the generator is fitted and supplies,
machine, and which may be mounted on the engine, shall be
where necessary, the auxiliaries indispensable to the oper-
,
removed for the test. The following non-exhaustive list is given
ation of the engine.
! as an example :
I
b) Starting other than electrical: if there are any electrically
- machine hydraulic system(s) pumps; operated accessories indispensable to the operation of the
engine, the generator is fitted to supply these accessories.
- air compressor for brakes; Otherwise it is removed.
3

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IS0 9249 : 1989 (E)
5.3.6 Observed brake load, fuel consumption and inlet air
In either case, the system for producing and accumulating the
temperature data shall be recorded simultaneously and shall in
energy necessary for starting is fitted and operates in the
each case be the average of two stabilized sustained readings
unloaded condition.
% for the brake load and fuel
which do not vary by more than 2
consumption.
5.2 Setting conditions
The setting conditions for the test to determine net power are
5.3.7 The temperature of the coolant at the outlet from the
indicated in table 2.
engine shall be kept within f 5 K ( f 5 OC) of the upper ther-
mostatically controlled temperature specified by the manufac-
Table 2 - Setting conditions
turer. If no temperature is specified by the manufacturer, the
-
temperature shall be 353 K f 5 K (80 OC f 5 OC). For air-
1 Setting of
cooled engines, the temperature at a oint indicated by the
carburettork4
__
manufacturer shall be kept within -20 1 K ( -20 OC) of the
2 Setting of injection In accordance with the
maximum value specified by the manufacturer for the reference
pump delivery system manufacturer's production
___
specifications and used conditions.
3
Injection timing without further alteration
(timing curve) for the particular
__
application.
5.3.8 The fuel temperature shall be controlled at the inlet
4 Governor setting
to the fuel injection system to a temperature of 313 K I 3 K
Anti-pollution devices
5
- (40 OC k 3 OC). Where the test facility cannot maintain this
O
fuel inlet temperature, a correction factor as calculated by 6.4
shall be applied.
5.3 Test conditions
5.3.1 The net power test shall consist of a run at full throttle
5.3.9 The temperature of the lubricating oil measured in the
for spark-ignition engines and at fixed full load fuel injection
oil sump or at the outlet from the oil cooler, if fitted, shall be
pump setting for compression-ignition engines, the engine
maintained within the limits set by the engine manufacturer.
being equipped as specified in table 1.
5.3.10 An auxiliary regulation system may be used if
5.3.2 Performance data shall be obtained under stabilized
necessary to maintain temperatures within limits specified in
operating conditions, with an adequate fresh air supply to the
5.3.7, 5.3.8 and 5.3.9.
engine. The engine shall have been run-in in accordance with
the manufacturer's recommendations. Combustion chambers
may contain deposits, but in limited quantity. Test conditions
5.3.11 For compression-ignition engines, the fuel shall be one
such as inlet air temperature shall be selected as near to
supplied and delivered by the refinery to the customer without
reference conditions (see 6.2) as possible in order to minimize
any smoke-suppressant additives. In cases of dispute, tests
the magnitude of the correction factor.
shall be made with the CEC') reference fuel CEC RF-03-A-84
(see annex B). For spark-ignition engines, in cases of dispute,
5.3.3 The temperature of the inlet air to the engine (ambient
tests shall be carried out using CEC reference fuel CEC RF-OI-
air) shall be measured not more than 0,15 m upstream of the
A-80 or CEC RF-08-A-85 (see annex A or CI.
point of entry to the air filter, or, if no air filter is used, within
0.15 m of the air inlet horn. The thermometer or thermocouple
shall be shielded from radiant heat and located directly in the air
5.4 Test procedure
stream. It shall also be shielded from fuel spray-back. A suffi-
cient number of locations shall be used to give a representative Record data at a sufficient number of engine rotational fre-
average inlet temperature. quencies to define the engine torque curve between the
manufacturer's rated engine rotational frequency and the
engine rotational frequency at which maximum torque is
5.3.4 No data shall be taken until torque, rotational frequency
developed. The average of at least two stabilized measure-
and temperature have been maintained substantially constant
ments is to be determined.
for at least 1 min.
5.3.5 The engine rotational frequency during a run or reading
5.5 Data to be recorded
shall not deviate from the selected rotational frequency by more
than f 1 % or f 10 r/min, whichever is greater. Data to be recorded are those indicated in clause 8.
Co-ordinating European Council for the Development of Performance Tests for Lubricants and Engine Fuels. These fuels can be obtained from
1)
the Council at
61 New Cavendish Street
London WIM 8AR
United Kingdom
This information is given for the convenience of users of this International Standard and does not constitute an endorsement by IS0 of the product
named. Equivalent products may be used if they can be shown to lead to the same results.
4

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IS0 9249 : 1989 (E)
6.3.1 Definition of T and ps in correction
6 Correction factors
factors a, and ad
6.1 Definition of factor a
T is the absolute temperature in kelvins at the air inlet to
the engine;
This is the factor by which the observed power shall be
multiplied to determine the corrected engine power, Po, under
ps is the total dry atmospheric pressure, in kilopascals, i.e.
the reference atmospheric conditions specified in 6.2 :
the total barometric pressure minus water vapour pressure.
Po = aP
6.3.2 Compression-ignition engines - Factor ad
where
The power correction factor for compression-ignition engines
at constant fuel delivery, ad, is obtained by applying the formula:
a is the correction factor (a, or ad);
ad = (fa)fm
P is the measured (observed) power.
where
6.2 Atmospheric conditions
fa is the atmospheric factor (see 6.3.2.1);
f, is the characteristic parameter for each type of engine
6.2.1 Reference atmospheric conditions
and adjustment (see 6.3.2.2).
9 The reference atmospheric conditions are taken to be as given
' in 6.2.1.1 and 6.2.1.2.
6.3.2.1 Atmospheric factor, fa
This factor indicates effect of environmental conditions
6.2.1.1 Temperature
(pressure, temperature and humidity) on the air drawn in by the
engine. The atmospheric factor formula differs according to the
The reference temperature, To, is 298 K (25 OC).
type of engine, and shall be calculated from the formula in a)
or b):
6.2.1.2 Dry pressure
a) naturally aspirated and mechanically pressure-charged
The reference dry pressure, pso, is 99 kPa.l)
engines :
6.2.2 Test atmospheric conditions
The test atmospheric conditions shall be within the values
b) turbocharged engines with or without cooling of charge
given in 6.2.2.1 and 6.2.2.2 during the test.
air:*)
6.2.2.1 Temperature, T
For spark-ignition engines
where T and ps are as defined in 6.3.1.
0
288 K (15 OC) < T < 308 K (35 OC)
6.3.2.2 Engine factor, f,
For compression-ignition engines
f, is a function of corrected fuel flow, qc, and shall be
283 K (IO OC) a T < 313 K (40 OC)
calculated from the formula :
6.2.2.2 Dry pressure, pç
f, = 0,036qc - 1,14
For all engines
where
80 kPa < ps < 110 kPa
in which
6.3 Determination of correction factors
q is the fuel flow in milligrams per cycle per litre of engine
NOTE - The test may be carried out in air-conditioned test rooms
swept volume [mg/(l.cycle)l;
where the atmospheric conditions may be controlled.
The dry pressure is based on a total pressure of 100 kPa and a vapour pressure of 1 kPa.
1)
The correction factor should be regarded as provisional. Studies are in progress to establish a more accurate formula.
2)
5

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IS0 9249 : 1989 (E)
r is the pressure ratio of compressor outlet and com- tor applied. If the device is still operating at 299 K (26 OC), then
pressor inlet (r = 1 for naturally aspirated engines).
the test is made with the device operating normally and the
exponent of the temperature term in the correction factor shall
be taken as zero (no temperature correction).
This formula is valid for a value interval of qc included between
40 mg/(l.cycle) < qc < 65 mg/(l.cycle).
6.4 Correction for fuel temperature outside the
For qc values lower than 40 mg/(l-cycle), a constant value off,
specified value of 313 K f 3 K (40 OC f 3 OC)
equal to 0,3 U, = 0,3) shall be taken.
The fuel consumption, Gf, in litres per hour, and gf, in grams
For qc values higher than 65 mg/(l.cycle), a constant value of
per kilowatt hour, are given by the following formulae respec-
f, equal to 1,2 U, = 1,2) shall be taken (see figure 1).
tively :
6.3.2.3 Limitation in use of correction formula
This correction formula is only applicable if
and
Fr
gf = - x 1 O00
P
If these limits are exceeded the corrected value obtained shall
be given, and the test conditions (temperature and pressure) where
precisely stated in the test report.
b is the fuel consumption within a unit of time in cubic
centimetres;
6.3.3 Spark-ignition engines (naturally aspirated and
t is the fuel consumption measuring time, in seconds;
pressure-charged)
P is the output;
Factor a, is calculate
...