ISO 8854:2012

Road vehicles — Alternators with regulators — Test methods and general requirements

ISO 8854:2012 specifies test methods and general requirements for the determination of the electrical characteristic data of alternators for road vehicles. It applies to alternators, cooled according to the supplier's instructions, mounted on internal combustion engines.

Véhicules routiers — Alternateurs avec régulateurs — Méthodes d'essai et conditions générales

General Information

• Status: Published
• Publication Date: 31-May-2012
• ICS: 43.060.50 - Electrical and electronic equipment. Control systems
• Technical Committee: ISO/TC 22/SC 32 - Electrical and electronic components and general system aspects
• Drafting Committee: ISO/TC 22/SC 32/WG 7 - Functional characteristics of starting devices and electrical generators
• Current Stage: 9060 - Close of review
• Start Date: 02-Dec-2028

Relations

• Revises: ISO 8854:1988 - Road vehicles — Alternators with regulators — Test methods and general requirements
• Effective Date: 29-Aug-2009

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 8854
Second edition
2012-06-01
Road vehicles — Alternators with
regulators — Test methods and general
requirements
Véhicules routiers — Alternateurs avec régulateurs — Méthodes d’essai
et conditions générales
Reference number
ISO 8854:2012(E)
©
ISO 2012

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ISO 8854:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, 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 either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

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ISO 8854:2012(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Terms and definitions . 1
3 Test conditions . 2
3.1 Ambient temperature . 2
3.2 Air pressure . 2
3.3 Sense of rotation . 2
3.4 Drive control . 2
3.5 Load current control . 2
3.6 Measuring accuracy . 2
3.7 Measured values . 3
4 Test equipment . 3
4.1 Ambient air . 3
4.2 Terminal connecting plan . 3
4.3 Measuring system . 4
5 Measurement procedure . 5
5.1 Current/rotational frequency characteristic . 5
5.2 Partial load measurement . 6
5.3 Testing functional ability of regulator . 6
5.4 Load dump . 6
5.5 Voltage ripple . 9
5.6 Efficiency determination .12
6 Method of calculation of efficiency .13
6.1 Determination of efficiency .13
6.2 Determination of weighted efficiency .13
7 Presentation of results .13
Bibliography .15
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ISO 8854:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 8854 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 3, Electrical
and electronic equipment.
This second edition cancels and replaces the first edition (ISO 8854:1988), which has been technically revised.
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INTERNATIONAL STANDARD ISO 8854:2012(E)
Road vehicles — Alternators with regulators — Test methods
and general requirements
1 Scope
This International Standard specifies test methods and general requirements for the determination of the
electrical characteristic data of alternators for road vehicles.
It applies to alternators, cooled according to the supplier’s instructions, mounted on internal combustion engines.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
alternator frequency
n
G
−1
alternator rotational frequency in reciprocal minutes (min )
2.2
cut-in speed
n
A
−1
alternator rotational frequency, in reciprocal minutes (min ), at which the alternator begins to supply current
when speed is increased for the first time, depending on pre-exciting power (input), speed changing velocity,
battery voltage, residual flux density of the rotor, and regulator characteristics
2.3
efficiency
η
alternator efficiency calculated from the measured values of voltage, current, speed and torque
2.4
minimum application speed
n
L
−1
alternator rotational frequency, in reciprocal minutes (min ), which corresponds approximately to the idling
speed of the engine
2.5
minimum application current
I
L
current, in amperes, which is delivered by a warmed-up alternator at test voltage U and minimum
t
application speed n
L
2.6
rated current
I
R
−1
minimum current, in amperes, which the warmed-up alternator shall supply at a speed n = 6 000 min and
R
at test voltage U
t
NOTE The mean value minus twice the standard deviation should be stated unless the customer has requested otherwise.
2.7
rated speed
n
R
−1
alternator rotational frequency, in reciprocal mintues (min ), at which the alternator supplies its rated current,
−1
I , specifying the rated speed as n = 6 000 min
R R
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ISO 8854:2012(E)
2.8
test voltage
U
t
specified value, in volts, at which the current measurements shall be carried out
2.9
weighted efficiency
η
W
speed-evaluated mean value of efficiency at different alternator speeds
2.10
zero-amp. speed
n
0
−1
alternator rotational frequency, in reciprocal minutes (min ), at which the alternator reaches the specified test
voltage, U , without any current output
t
NOTE When plotted on a graph, this is the point at which the current/speed characteristic l = ƒ(n) intersects the abscissa.
3 Test conditions
3.1 Ambient temperature
Tests shall be carried out at an ambient temperature of T = (23 ± 5) °C and may optionally also be performed
amb
at higher temperatures.
3.2 Air pressure
Tests shall be carried out at the standard atmospheric pressure.
Deviating conditions (e.g. measuring location, altitude, weather) shall be recorded.
3.3 Sense of rotation
Sense of alternator rotation shall be in accordance with the supplier’s specification.
3.4 Drive control
−1
The drive control shall meet the set alternator frequency values with a limit deviation of (n ± 5) min .
G set
3.5 Load current control
The load current control shall meet the requested set current values with a limit deviation of (l ± 1,0) A.
Set
3.6 Measuring accuracy
The test equipment shall allow measurements of all parameters to be carried out within the limit deviations
specified in Table 1.
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ISO 8854:2012(E)
Table 1 — Accuracy of test equipment
Parameters Limit deviation
Voltage ±0,1 % of measured value
Current ±0,2 % of measured value
Torque ±0,5 % of rated value of torque sensors
−1
Rotational frequency ±2 min
Ambient temperature ±1 K
Air pressure ±5 hPa
Test period ±1 s
3.7 Measured values
All measured values shall be obtained at the end of each holding time of an operating point.
Each data record shall comprise at least the following measured values:
n alternator rotational frequency (actual value = measured value);
G actual
I alternator current (actual value = measured value);
G actual
U alternator voltage;
G
M alternator torque, if needed;
T ambient temperature;
amb
t time of acquisition of measured values from start of testing.
M
4 Test equipment
4.1 Ambient air
4.1.1 Flow rate
The input air flow within the alternator area shall be constant and reproducible. The maximum permissible flow
rate shall be limited to 1 m/s.
4.1.2 Direction of flow
The direction of the air flow within the alternator area shall be constant and reproducible. If possible, the air
should flow from bottom to top.
4.1.3 Measurement of ambient temperature
The measuring point is located on the B side of the alternator (slip ring end, shield side) in line with the shaft
and at a distance of (10 ± 1) cm from the protective cap.
The spatial extent of the sensitive part of the temperature probe shall be limited to a cube with edges of
20 mm in length.
4.2 Terminal connecting plan
For the tests, connections shall be established according to Figure 1. During the tests, the ignition switch is “on”.
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ISO 8854:2012(E)
Key
1 load control lamp
2 D+ or L− lamp connection alternator
3 optional filter capacitor or test stand
4 battery/storage device
5 ignition lock, terminal 15
I alternator current
G
R load resistor
L
U alternator voltage
G
Figure 1 — Test circuit schematic
4.2.1 Voltage measurement
A voltmeter shall be connected directly to the output terminal(s) and/or alternator housing.
4.2.2 Filter capacitor C (optional)
A capacitor should be connected to the output terminals of the alternator. The connecting cable shall be as
short as possible.
— Capacitor type: polarized electrolytic capacitor
— Capacity: 68 000 µF
2
— Connecting cable: cross-section of at least 4 mm , maximum cable length (2 × 1) m, copper
4.3 Measuring system
The measuring system shall record the parameters to be measured. Voltage, current, speed and torque shall be
measured simultaneously. If parameters are recorded subsequently, there shall be no more than 1 s between
the measurements of the first and last parameter.
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ISO 8854:2012(E)
5 Measurement procedure
5.1 Current/rotational frequency characteristic
This measurement shall be performed at full load. The alternator works at full load when the regulator duty
cycle is 100 %, i.e. when the full excitation current is available.
In the measuring circuit, a battery and an adjustable resistor, R , shunted to the battery shall be used (see Figure 1).
L
The tests shall be conducted using a power-storing device (e.g. lead-acid battery, Li-ion battery or large capacitors).
The measurements shall be carried out using an integral or separate regulator.
To prevent the regulator from working, measurements shall be made at the following test voltages (for lead-
acid batteries):
— (13,5 ± 0,1) V for 12 V systems;
— (27 ± 0,2) V for 24 V systems.
NOTE Measurements at other voltages are optional.
5.1.1 Warm tests — Rotational frequencies and measuring points
−1
Current measurements shall be taken at the following rotational frequencies (in min ). At each operating point,
the alternator shall reach equilibrium steady-state temperature before current values are recorded.
In order to simplify the measuring set-up, this should be ensured by specifying a set holding time for each
operating point:
1 500 – 1 800 – 2 000 – 2 500 – 3 000 – 3 500 – 4 000 – 5 000 – 6 000 – 8 000 – 10 000 – 12 000 – n
max
...