SIST EN 50304:2002
(Main)Electric ovens for household use - Methods for measuring the energy consumption
Electric ovens for household use - Methods for measuring the energy consumption
Supersedes HD 376 S2 * With calculation sheet in Excel * Corrigendum to EN issued March 2002
Elektrische Backöfen für den Hausgebrauch - Verfahren zur Messung des Energieverbrauchs
Fours électriques à usage domestique - Méthodes de mesure de la consommation d'énergie
Electric ovens for household use - Methods for measuring the energy consumption
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 50304:2002
01-september-2002
Electric ovens for household use - Methods for measuring the energy
consumption
Electric ovens for household use - Methods for measuring the energy consumption
Elektrische Backöfen für den Hausgebrauch - Verfahren zur Messung des
Energieverbrauchs
Fours électriques à usage domestique - Méthodes de mesure de la consommation
d'énergie
Ta slovenski standard je istoveten z: EN 50304:2001
ICS:
97.040.20 âWHGLOQLNLGHORYQLSXOWL Cooking ranges, working
SHþLFHLQSRGREQLDSDUDWL tables, ovens and similar
appliances
SIST EN 50304:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50304:2002
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SIST EN 50304:2002
EUROPEAN STANDARD EN 50304
NORME EUROPÉENNE
EUROPÄISCHE NORM May 2001
ICS 97.040.20 Supersedes HD 376 S2:1984
English version
Electric ovens for household use -
Methods for measuring the energy consumption
Fours électriques à usage domestique - Elektrische Backöfen für den
Méthodes de mesure de la consommation Hausgebrauch -
d'énergie Verfahren zur Messung des
Energieverbrauchs
This European Standard was approved by CENELEC on 2000-04-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any
other language made by translation under the responsibility of a CENELEC member into its own
language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50304:2001 E
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EN 50304:2001 - 2 -
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 59X, Consumer
information related to household electrical appliances.
According to the decision of CLC/TC 59X, taken at the meeting in Brussels on 7th/8th October 1996 and
confirmed at the meeting in Paris on 26th/27th March 1998 this standard has been drawn up as a self-
contained CENELEC document. But it follows, as far as suitable, the structure of IEC 60350:1999.
Based on an interlaboratory test performed by nine laboratories test results obtained according to this
standard are for direct comparison and are considered sufficiently reproducible within given limits for the
purpose of energy labelling in according to the Commission Directive on energy labelling and standard
product information.
This European Standard has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association and covers essential requirements of EC
Directive 92/75/EEC on ”Indication by labelling and standard product information of the consumption of
energy and other resources by household appliances“.
It deals only with those test procedures that are required for the Commission Directive on Energy
labelling for ovens.
It also defines permitted tolerances to values declared by the manufacturer and control procedures for
checking these values.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50304
on 2000-04-01.
This European Standard supersedes HD 376 S2:1984.
The following dates were fixed:
- latest date by which the EN has to be implemented
- at national level by publication of an identical
- national standard or by endorsement (dop) 2001-11-01
- latest date by which national standards conflicting
- with the EN have to be withdrawn (dow) 2003-04-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexe A is normative, annexes B, C and D are informative.
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Contents
Page
1 Scope .4
2 Object . 4
3 Normative references. 4
4 Definitions. 4
5 List of measurements. 5
6 General conditions for measurements . 5
7 Dimensions . 7
8 Energy consumption and heat-up time . 8
9 Data to be reported . 12
10 Airborne acoustical noise. 12
11 Tolerances and control procedures. 12
Annexes
A Description of the test brick . 15
B Explanation of the Subscripts and Superscripts . 16
C Calculation Sheet: Energy Consumption of Electric Ovens. 17
D Bibliography . 19
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1 Scope
This standard applies to electric ovens for household use.
It is not applicable to:
- microwave ovens and microwave combination ovens;
- small cavity ovens (see 4.4);
- ovens without adjustable temperature control;
- heating functions others than defined in 4.1 - 4.3.
2 Object
The object of this standard is to specify in accordance with the Council Directive on energy labelling and
standard product information:
- energy consumption using a standardised load during a standardised test procedure;
- some performance characteristics (like volume, time for heating a load and baking trays area);
- permitted tolerances to values declared by the manufacturer and control procedures for checking
these declared values.
This standard is concerned neither with safety nor with performance requirements.
3 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to applies.
EN 60350 1999 Electric cooking ranges, hobs, ovens and grills for household use -
Methods for measuring performance (IEC 60350:1999)
EN 60584-2 1993 Thermocouples – Part 2: Tolerances (IEC 60584-2:1982 + A1:1989)
EN 61591 1997 Household range hoods - Methods for measuring the performance
(IEC 61591:1997)
4 Definitions
For the purpose of this standard the following definitions apply:
4.1
conventional heating function
food is cooked by radiation and natural convection only
NOTE This does not include ovens that have a top heating element only (i.e. for the grilling function).
4.2
forced air circulation function
heat transmission to the food by forced air convection, i.e. circulating the air with the help of a fan
NOTE This does not include circulated air functions which operate a grill element only.
4.3
hot steam function
food is heated with hot steam (T >> 100 °C) at ambient pressure (1 bar)
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4.4
small cavity oven
an oven with the following dimensions related to the usable volume:
- both width and depth < 250 mm,
- or height < 120 mm.
NOTE The definition of small cavity ovens in this standard is due to the size of the artificial standard load.
4.5
multiple cavity appliance
an appliance that has more than one separate oven cavity in which food is cooked and which can be
controlled independently, but cannot be installed separately
5 List of measurements
5.1 Dimensions
- Overall dimensions (clause 7);
- Dimensions of the usable volume and the surface area (clause 7).
5.2 Energy consumption and heating times
- Preheating of the empty oven (8.2);
- Heating of the load (8.3).
6 General conditions for measurements
6.1 General
The manufacturer's instructions regarding installation of the oven shall be followed.
Prior to every test the whole appliance (this includes the material and the insulation) shall be at ambient
temperature. In multiple cavity appliances each oven cavity has to be measured separately. Only the
cavity measured shall be switched on.
In case an oven has several variants of the functions as described in 4.1 – 4.3, the manufacturer can
choose the variant to be tested. This has to be reported (see clause 9).
Unless otherwise specified, measurements are conducted under the following conditions:
6.2 Ambient temperature
The tests are carried out in a substantially draught-free room in which the ambient temperature is
maintained at (23 + 2) °C during the complete test.
This ambient temperature is measured at a point that is at the same height as the centre of the usable
volume of the oven cavity and at a distance of 0,5 m diagonally from one of the front edges of the
appliance, see Figure 1.
The measurement of the ambient temperature shall not be influenced by the oven itself or by any other
appliance.
6.3 Electrical supply
The supply voltage shall be maintained at the main terminal at 230 V + 1 % or at 400 V + 1 %, as
defined by the manufacturers installation guide, while the heating elements are switched on. The supply
frequency shall be at nominal 50 Hz + 1 %.
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The supply voltage measured during the tests shall be recorded.
NOTE In case of a fixed cable the plug (or the end of the cable) is the reference point to maintain the voltage.
Top view
Oven
0,5 m
+
Thermocouple
Figure 1 - Position of the thermocouple
6.4 Load
The load for test 8.3 shall be a brick with two holes for temperature measurements as shown in annex A.
A new brick shall be dried before using it for the first time in forced air circulation in an oven of about 50 l
volume at > 175 °C for three hours. No more than two bricks shall be dried at the same time in the same
oven.
The weight m of the completely dry brick without thermocouples shall be measured within 5 min after
d
removal from the oven and shall be noted in g. The dry weight m shall be in accordance with the dry
d
weight specified in annex A. The brick shall be identified for accurate calculation of the water absorption
according to 8.3.2.
Place markings 32 mm from the measuring point of the two thermocouples with steel tube and insert the
thermocouples into the holes until the marking matches with the surface of the brick. The thermocouples
shall be fixed to ensure that the measuring points remain at a depth of 32 mm during the whole test
procedure.
NOTE 1 The thermocouples may be fixed by means of a droplet of silicon glue at the surface of the brick or by
other suitable means, see Figure 2.
NOTE 2 Other types of thermocouples may be used provided they are shown to give the same results. (Care
should be taken that the measuring point is the first contact point of the two thermowires.)
NOTE 3 Between test series the brick should be stored in a refrigerator, preferably not soaked with water. The
brick soaking water should be kept (to reduce dissolving processes); i.e. re-use of the brick storage water. A brick
that has already been soaked in water needs at least eight hours to be dried as described above.
NOTE 4 Due to the porosity of the brick care should be taken that the holes of the brick are not enlarged if the
thermocouples are removed and reinserted.
NOTE 5 A brick can be used for about 20 tests when handled with normal care.
Screw with a hole of 1 mm
Steel tube
Measuring point
Nut 32
Figure 2 - Example of a method of fixing a thermocouple
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6.5 Instrumentation
Air temperature measurements in the empty oven are made with a thermocouple with a welded point
(not with a black copper plate).
Temperature measurements in the load are made with two thermocouples with 1 mm steel tube
diameter, class 1 according to EN 60584-2. The thermocouple shall be accurate to + 1,5 K.
NOTE The steel tube of the thermocouple eases the insertion of the thermocouple into the brick. See also note 2
in 6.4.
The temperature measurement system excluding the thermocouple shall be accurate to + 1,0 K.
The energy measurements shall be accurate to + 1,5 % or + 10 Wh whatever is the greater.
The measurement of the voltage shall be accurate to + 0,5 %.
The measurements of mass shall be accurate to + 3 g.
The measurements of time shall be accurate to + 5 s.
6.6 Positioning of the appliance
6.6.1 General conditions
The appliances shall be installed according to the manufacturer's instructions.
6.6.2 Particular conditions
- Floor-standing appliances are positioned between kitchen cabinets in accordance with the
manufacturer's instructions;
- Built-in ovens are installed in a test enclosure including openings for ventilation, if required by the
manufacturer. If the manufacturer's instructions give a range for the inner dimension of the enclosure
the smallest dimension(s) shall be used.
- Other ovens are placed away from side walls with their back against a wall, unless otherwise specified
in the manufacturer's instructions.
- Ovens with integrated air-extraction by a fan (or similar device) to the outside of the building, for tests
according to clause 8, the air outlet is discharged into a flue which has a pressure drop of 50 Pa when
there is an airflow of 200 m³/h.
NOTE 1 The material and colour of the enclosing or adjacent cabinet(s) or walls is not defined in order to be in
line with kitchen cabinets in practice.
NOTE 2 The condition of measurement for ovens with integrated air-extraction is similar to EN 61591:1997.
7 Dimensions of the usable volume and the surface area
The height, width and depth of the usable volume within the cavity are measured as shown in Figure 3
and stated in mm.
The usable volume is calculated from these three dimensions and stated in litres, rounded to the nearest
whole litre.
The surface area of the largest baking sheet (if more than one) is calculated from the usable depth and
width of the baking sheet and is measured 5 mm above its surface and stated in cm², rounded to the
nearest 10 cm². If the appliance is delivered without baking sheets but with a grid, the surface of the grid
shall be measured accordingly.
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8 Energy consumption and time
8.1 Measurement of oven temperature
The oven temperature of each heating function, as appropriate (see 4.1 to 4.3), shall be measured
separately. During the test only one heating function (see 4.1 to 4.3) shall be used.
The air temperature in the empty oven is measured with a thermocouple according to 6.5 fixed to the
grid which is delivered with the oven and placed in the oven in a way that the welding point of the
thermocouple is located at the centre of the usable volume of the oven with a distance of at least 30 mm
from the grid.
8.2 Preheating of the empty oven
The purpose of this test is to measure the energy consumption and time it takes to preheat an empty
oven from room temperature by a given temperature rise.
A thermocouple is placed in the oven according to 8.1. It is led through the door gap in a way that the
door is completely closed without applying additional force. The temperature control is set at the
maximum position for each function. The oven is heated until the rise is:
- 180 K for conventional heating function;
- 155 K for forced air circulation function,
- 155 K for hot steam function,
NOTE 1 The completely closed door is very essential for the measurements according to 8.2 and 8.3.
The temperature rise is the difference of the oven temperatures (measured according to 8.1) at the
beginning and at the end of the test.
The time t in minutes and seconds and the energy consumption E in kWh shall be measured.
ph ph
If the oven has an additional preheating setting, the test is repeated with this setting.
NOTE 2 The energy consumption of components, such as lamps and fans which are automatically switched on
with the oven, is included in the measurement.
8.3 Energy consumption and time for heating a load
8.3.1 Purpose
The purpose of this test is to measure the energy consumption and the time for heating a load. The load
is a water saturated brick as defined in 8.3.2 which simulates both the thermal properties and the water
content of food (e.g. meat).
8.3.2 Preparation
Before heating the brick, which has been treated according to 6.4, it s
...
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