ISO 789-3:2015

SLOVENSKI STANDARD
SIST ISO 789-3:2016
01-maj-2016
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SIST ISO 789-3:1997
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Agricultural tractors - Test procedures - Part 3: Turning and clearance diameters
Tracteurs agricoles - Méthodes d'essai - Partie 3: Diamètres de braquage et de
dégagement
Ta slovenski standard je istoveten z: ISO 789-3:2015
ICS:
65.060.10 Kmetijski traktorji in prikolice Agricultural tractors and
trailed vehicles
SIST ISO 789-3:2016 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 789-3:2016

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SIST ISO 789-3:2016
INTERNATIONAL ISO
STANDARD 789-3
Third edition
2015-09-01
Agricultural tractors — Test
procedures —
Part 3:
Turning and clearance diameters
Tracteurs agricoles — Méthodes d’essai —
Partie 3: Diamètres de braquage et de dégagement
Reference number
ISO 789-3:2015(E)
©
ISO 2015

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SIST ISO 789-3:2016
ISO 789-3:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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Tel. +41 22 749 01 11
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copyright@iso.org
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ii © ISO 2015 – All rights reserved

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SIST ISO 789-3:2016
ISO 789-3:2015(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Terms and definitions . 1
3 Apparatus . 5
4 General requirements . 5
4.1 Test area . 5
4.2 Tractor test requirements . 5
4.2.1 Tire and wheel equipment . 5
4.2.2 Track (tread) setting . 5
4.2.3 Other settings . 5
5 Procedure. 6
5.1 Right-hand turn, without brakes . 6
5.1.1 Direct measurement . 6
5.1.2 Alternate GPS method . 6
5.2 Left-hand turn, without brakes . 6
5.3 Right-hand turn, with brakes . 7
5.4 Left-hand turn, with brakes . 7
6 Test report .10
Annex A (informative) Specimen test report .11
© ISO 2015 – All rights reserved iii

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SIST ISO 789-3:2016
ISO 789-3:2015(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
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For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee 2, Common tests.
This third edition cancels and replaces the second edition (ISO 789-3:1993), which has been
technically revised.
ISO 789 consists of the following parts, under the general title Agricultural tractors — Test procedures:
— Part 1: Power tests for power take-off
— Part 2: Rear three-point linkage lifting capacity
— Part 3: Turning and clearance diameters
— Part 4: Measurement of exhaust smoke
— Part 5: Partial power PT0 – Non-mechanically transmitted power
— Part 6: Centre of gravity
— Part 7: Axle power determination
— Part 8: Engine air cleaner
— Part 9: Power tests for drawbar
— Part 11: Steering capability of wheeled tractors
— Part 12: Low temperature starting
ISO/OECD 789 consists of the following parts, under the general title Agricultural tractors – Test procedures:
— Part 10: Hydraulic power at tractor/implement interface
iv © ISO 2015 – All rights reserved

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SIST ISO 789-3:2016
INTERNATIONAL STANDARD ISO 789-3:2015(E)
Agricultural tractors — Test procedures —
Part 3:
Turning and clearance diameters
1 Scope
This part of ISO 789 specifies a method of determining the turning and clearance diameters of wheeled
agricultural tractors.
It applies to wheeled agricultural tractors having at least two axles fitted with pneumatic tyres.
2 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
2.1
agricultural tractor
self-propelled agricultural vehicle having at least two axles and wheels, or endless tracks, particularly
designed to pull agricultural trailers and to pull, push, carry and operate implements used for
agricultural work (including forestry work), which may be provided with detachable loading platform
Note 1 to entry: The agricultural vehicle has a maximum design speed of not less than 6 km/h and may be
equipped with one or more seats.
[SOURCE: ISO 12934:2013, 3.1]
2.2
track
tread
distance at ground level between two vertical planes passing through the centreline
of ground contact of the tires parallel to the median plane of the tractor with the wheels in the straight
ahead position
Note 1 to entry: In the case of dual wheels, it is the distance at ground level between two planes passing through
the centreline of the dual wheels.
Note 2 to entry: See Figure 1.
© ISO 2015 – All rights reserved 1

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SIST ISO 789-3:2016
ISO 789-3:2015(E)

Figure 1 — Track (tread) of the wheeled tractor
2.3
wheelbase
horizontal distance between the two vertical planes passing through the rotational centrelines of the
wheels, where one plane is for the front wheels and the other for the rear wheels
Note 1 to entry: In the case of a tractor equipped with a rear tandem, it is the distance between two vertical
planes passing through the centres of the front wheel and the vertical plane midway between the wheel centres
of the two axles of the tandem.
Note 2 to entry: See Figure 2.
2 © ISO 2015 – All rights reserved

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SIST ISO 789-3:2016
ISO 789-3:2015(E)

Figure 2 — Wheelbase of the wheeled tractor
2.4
turning diameter
diameter of the circular path described by the centre of tire contact with the surface of the test site of
the wheel describing the largest circle when the tractor is executing its sharpest practicable turn under
the test conditions described in Clause 5
Note 1 to entry: See Figure 3.
2.5
clearance diameter
diameter of the smallest circle which will enclose the outermost points of projection of the
...