EN 60034-2:1996

SLOVENSKI STANDARD
01-april-1999
Rotating electrical machines - Part 2: Methods for determining losses and
efficiency of rotating electrical machinery from tests (excluding machines for
traction vehicles) (IEC 60034-2:1972 + IEC 60034-2A:1974)
Rotating electrical machines -- Part 2: Methods for determining losses and efficiency of
rotating electrical machinery from tests (excluding machines for traction vehicles)
Drehende elektrische Maschinen -- Teil 2: Verfahren zur Bestimmung der Verluste und
des Wirkungsgrades von drehenden elektrischen Maschinen aus Prüfungen
(ausgenommen Maschinen für Schienen- und Straßenfahrzeuge)
Machines électriques tournantes -- Partie 2: Méthodes pour la détermination des pertes
et du rendement des machines électriques tournantes à partir d'essais (à l'exclusion des
machines pour véhicules de traction)
Ta slovenski standard je istoveten z: EN 60034-2:1996
ICS:
29.160.01 Rotacijski stroji na splošno Rotating machinery in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
INTERNATIONALE IEC
34-2A
INTERNATIONAL
Première édition
STANDARD
First edition
Premier complément à la Publication 34-2 (1972)
Machines électriques tournantes
Deuxième partie:
Méthodes pour la détermination des pertes et du rendement
des machines électriques tournantes à partir d'essais
(à l'exclusion des machines pour véhicules de traction)
Mesure des pertes par la méthode calorimétrique
First supplement to Publication 34-2 (1972)
Rotating electrical machines
Part 2:
Methods for determining losses and efficiency
of rotating electrical machinery from tests
(excluding machines for traction vehicles)
Measurement of losses by the calorimetric method
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CONTENTS
Page
FOREWORD 5
PREFACE 5
INTRODUCTION 7
3.1 List of symbols 7
SECTION ONE — GENERAL
Clause
1. General 9
2. Determination of losses Pl by measurement of the volume rate of
flow and rise in temperature of the
cooling medium 9
3. Losses PI measured electrically using the calorimetric calibration method 9
4. Stable conditions 11
5. Losses Pz
not transmitted to the cooling medium 11
6.
Losses external to the reference surface
Pe 13
SECTION
Two — WATER AS THE COOLING MEDIUM
7. Application and basic relationship 15
8. Measurement of water flow 15
9. Measurement of the temperature rise of the water 17
10. Measuring accuracy 19
SECTION THREE — AIR AS THE COOLING MEDIUM
11. Application and basic relationship 19
12. Determination of the mass rate of flow 21
13. Measurement of the temperature rise of the air 25
14. Determination of the specific heat capacity of the air 25
15. Measuring accuracy 25
SECTION FOUR — PRACTICAL CONSIDERATIONS
16.
Preparations for calorimetric measurements with liquid coolants 27
17. Connections and equipment for calorimetric measurements with liquid coolants 29
FIGURES 30
— 5 —
INTERNATIONAL ELECTROTECHNICAL COMMISSION
FIRST SUPPLEMENT TO PUBLICATION 34-2 (1972)
Rotating electrical machines
Part 2 : Methods for determining losses and efficiency of rotating electrical machinery from tests
(excluding machines for traction vehicles)
Measurement of losses by the calorimetric method
FOREWORD
1) The formal decisions or agreements of the I E C on technical matters, prepared by Technical Committees on which all the National
Committees having a special interest therein are represented, express, as nearly as possible, an international consensus of opinion
on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National Committees in that sense.
3) In order to promote international unification, the I EC exp
resses the wish that all National Committees should adopt the text of the
I EC recommendation for their national rules in so far as national conditions will permit. Any divergence between the I EC recom-
mendations and the corresponding national rules should, as far as possible, be clearly indicated in the latter:
PREFACE
This recommendation has been prepared by Sub-Committee 2D, Losses and Efficiency, of I E C Technical
Committee No. 2, Rotating Machinery.
It forms the first supplement to I E C Publication 34-2, Rotating Electrical Machines, Part 2: Methods for Deter-
mining Losses and Efficiency of Rotating Electrical Machinery from Tests (Excluding Machines for Traction
Vehicles).
A first draft was discussed at the meetings held in London in 1968 and in Bucharest in 1970. As a result of this latter
meeting, a final draft, document 2D(Central Office)17, was submitted to the National Committees for approval
under the Six Months' Rule in August 1971. Amendments, document 2D(Central Office)19, were submitted to the
National Committees for approval under the Two Months' Procedure in February 1973.
The following countries voted explicitly in favour of publication:
Australia Portugal
Austria Romania
Belgium South Africa (Republic of)
Denmark Spain
Egypt Sweden
Finland Switzerland
France Turkey
Germany Union of Soviet
Israel Socialist Republics
Italy United Kingdom
Japan United States
Norway of America
Poland Yugoslavia
FIRST SUPPLEMENT TO PUBLICATION 34-2 (1972)
Rotating electrical machines
Part 2 : Methods for determining losses and efficiency of rotating electrical machinery from tests
(excluding machines for traction vehicles)
Measurement of losses by the calorimetric method
INTRODUCTION
The calorimetric method can be used to determine the efficiency of electrical rotating machinery:
— either by the determination of the total losses on load,
or by the determination of the segregated losses and hence the conventional total loss by summation of the
—
segregated losses.
Depending upon the circumstances, calorimetric measurements may be made in two different ways:
— either by measuring the quantity and rise in temperature of the cooling medium (direct method),
or by calibration of the rise in temperature of the cooling medium.
—
The calorimetric measurements should be performed for each cooling circuit, either primary or secondary,
separately.
The methods of loss determination given in this recommendation have been devised mainly for large generators,
but the principles used can also be applied to other machines.
Page 9
3.1 List of symbols
Complete the existing list of symbols by the following:
P; = losses inside reference surface
losses outside reference surface
Pe =
P1 = losses which are dissipated by the cooling circuits in the form of heat and which can be measured calori-
metrically
losses not transmitted to the cooling medium but which are dissipated through the reference surface by con-
P2 =
duction, convection, radiation, leakage, etc.
cp = specific heat capacity of the cooling medium
O = volume rate of flow of the cooling medium
= density of the cooling medium
At = rise in temperature of the cooling medium or temperature difference between the machine reference surface
and the external ambient temperature
y = exit velocity of cooling medium
a = discharge coefficient
Pl and Py
e = error in measurement of losses,
h = coefficient of heat transfer
Ap = difference between the static pressure in the intake nozzle and ambient pressure
A = cross-sectional area of the intake nozzle
= temperature
tl = inlet temperature of the cooling medium
t2 = outlet temperature of the cooling medium
b = barometric pressure
— 9 —
Page 53
Replace Clause 17 by the following:
SECTION ONE — GENERAL
1. To enable a classification of the total losses to be made, a " reference surface " is defined for the machine.
(Pi) are dissipated
This is a surface completely surrounding the machine such that all losses produced inside it
through it to the outside (see Figure 1, page 30).
The total losses of the machine consist of:
— losses inside the reference surface Pi,
— losses outside the reference surface Pe.
can be divided into two categories:
The losses inside the reference surface P i
Pi =P,±
P2
= being losses which can be measured calorimetrically and which are dissipated in the form of heat by the
P,
cooling circuits. These constitute the major part of the losses (internal losses which can be measured);
P2 = being losses not transmitted to the cooling medium and which are dissipated through the reference surface
by conduction, convection, radiation, leakage, etc. These constitute a small part of the total losses and can
be calculated (internal losses which cannot be measured).
ce.
Note. — P2 may be negative and therefore subtracted when heat flows into the reference surfa
may form part of the specified losses and should then be measured
Losses external to the reference surface
(Pe)
separately.
Note. — Losses in the bearings inside the reference surfa ce are included in the losses Pi.
2. Determination of losses Pl by measurement of the volume rate of flow and rise in temperature of the cooling medium
In stable operating conditions, and when thermal equilibrium has been achieved, the losses dissipated by the
cooling medium are:
P1=cpQeOt kW
where:
cp = specific heat capacity of the cooling medium in kJ/(kg K) at pressure p
Q = volume rate of flow of the cooling medium in ms/s
e = density of the cooling medium in kg/m $ at the temperature at the point of flow measurement
At = rise in temperature of the cooling medium in deg K.
If the cooling medium is water, the method of measurement is covered in Section Two.
If the cooling medium is air, the method of measurement is covered in Section Three.
losses may be measured using oil as a cooling medium, but it is preferred to measure on the water side of an oil-to-
Note. —Bearing
water heat exchanger because the thermal characteristics of water are better known.
measured electrically using the calorimetric calibration method
3. Losses Pi
3.1 General
In this method, a calibration curve relating the rise in temperature of the cooling medium to the losses dissipated
in the machine is determined by tests carried out under such conditions that the losses P i can be measured directly
P2 provided the conditions during
by electrical methods. This method does not require the evaluation of the losses
the tests are correctly adjusted, and this method may be used when direct calorimetric measurement of the cooling
circuit is impossible or when difficulties are encountered in putting it into practice.

— 11 —
3.2 Generation of losses for calibration
The machine losses shall be derived from an electrical power source to enable them to be measured accurately.
They can be produced inside the machine, either
a) in the form of normal machine losses, i.e. by supplying the
machine in the normal way and running it in the unloaded or loaded condition depending upon the losses required,
or
b) in the form of thermal losses from a special resistor inserted into the machine for the test in such a manner
that the losses produce a heat flow pattern similar to that occurri
...