Food processing machinery - Rotary rack ovens - Safety and hygiene requirements

This document specifies safety and hygiene requirements for the design and manufacture of rotary rack ovens which can be used with one or more mobile racks.
These ovens are intended for professional use in the food industry and workshops (bakeries, pastry-making, etc.) for the batch baking of foodstuffs containing flour, water and other ingredients and/or additives. This document applies to ovens used only for food products except for those containing volatile flammable ingredients (volatile organic compound, e.g. alcohol, oil, …). This document applies to ovens where the steam is generated by an evaporation process of drinking water on hot surfaces.
The following machines are excluded:
- experimental and testing machines under development by the manufacturer;
- machines for non-professional uses.
NOTE Due to the fact that rotary rack ovens are intended for professional uses, EN 60335-1 and EN 60335-2-42 are not applicable.
This document covers the technical safety requirements for the transport, installation, operation, cleaning and maintenance of these machines (see EN ISO 12100:2010, Clause 6).
This document deals with all significant hazards, hazardous situations and events relevant to rotary rack ovens when they are used as intended and under conditions of misuse which are reasonably foreseeable by the manufacturer (see informative Annex C).
The following hazards are not covered by this document:
- hazards from the use of gaseous fuel by gas appliances;
- hazards arising from electromagnetic compatibility issues;
- hazards from the use of trays made of or coated by silicone;
- hazards due to dismantling, disabling and scrapping.
This document does not deal with noise emitted by the machine.
This document is not applicable to rotary rack ovens which were manufactured before the date of its publication as an EN.

Nahrungsmittelmaschinen - Stikken-Backöfen - Sicherheits- und Hygieneanforderungen

Dieses Dokument legt die Sicherheits- und Hygieneanforderungen für die Gestaltung und Herstellung von Stikken-Backöfen fest, die mit einem oder mehreren fahrbaren Stikken verwendet werden können.
Diese Öfen sind für den professionellen Gebrauch in der Nahrungsmittelindustrie und in Geschäften (Bäckereien, Konditoreien usw.) zum nicht kontinuierlichen Backen von Nahrungsmitteln, die Mehl, Wasser und andere Zutaten und/oder Zusätze enthalten, vorgesehen. Dieses Dokument gilt für Öfen, die nur für Nahrungsmittel eingesetzt werden, ausgenommen solche, die flüchtige entflammbare Bestandteile (flüchtige organische Bestandteile, z. B. Alkohol, Öl, …) enthalten. Dieses Dokument gilt für Öfen, die in denen durch ein Verdampfungsverfahren mit Trinkwasser auf heißen Oberflächen Dampf erzeugt wird.
Die folgenden Maschinen sind ausgenommen:
-   Versuchs- und Prüfmaschinen, die in Entwicklung beim Hersteller sind;
-   Maschinen für nicht-professionelle Verwendungen.
ANMERKUNG   Bedingt durch die Tatsache, dass Stikken-Backöfen für die Verwendung im professionellen Umfeld vorgesehen sind, sind EN 60335 1 und EN 60335 2 42 nicht anwendbar.
Dieses Dokument behandelt die Anforderungen an die technische Sicherheit während des Transports, der Installation, des Betriebes, der Reinigung und Wartung dieser Maschinen (siehe EN ISO 12100:2010, Abschnitt 6).
Dieses Dokument behandelt alle signifikanten Gefährdungen, Gefährdungssituationen und Gefährdungsereignisse, die auf Stikken-Backöfen zutreffen, wenn sie bestimmungsgemäß und unter Bedingungen von durch den Hersteller vernünftigerweise vorhersehbaren Fehlanwendungen verwendet werden (siehe informativen Anhang C).
Die folgenden Gefährdungen werden in diesem Dokument nicht behandelt:
-   Gefährdungen bei Verwendung von gasförmigem Brennstoff bei Gasverbrauchseinrichtungen;
-   Gefährdungen, die von Problemen mit der elektromagnetischen Verträglichkeit herrühren;
-   Gefährdungen aus der Verwendung von Backblechen, die aus Silikon hergestellt oder damit beschichtet sind;
-   Gefährdungen durch Demontage, Außerbetriebnahme und Verschrottung.
Dieses Dokument behandelt nicht den von der Anlage ausgehenden Luftschall.
Diese Norm ist nicht anwendbar für Stikken-Backöfen, die vor dem Datum dieser Veröffentlichung als eine Europäische Norm gebaut wurden.

Machines pour les produits alimentaires - Fours à chariot rotatif - Prescriptions relative à la sécurité et l'hygiène

Le présent document (EN 1673:2020) a été élaboré par le Comité Technique CEN/TC 153 “Machines destinées à être utilisées avec des denrées alimentaires”, dont le secrétariat est tenu par DIN.
Cette Norme européenne devra recevoir le statut de norme nationale, soit par publication d'un texte identique, soit par entérinement, au plus tard en juin 2021, et toutes les normes nationales en contradiction devront être retirées au plus tard en juin 2021.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de droits de propriété intellectuelle ou de droits analogues. Le CEN et/ou le CENELEC ne saurait [sauraient] être tenu[s] pour responsable[s] de ne pas avoir identifié de tels droits de propriété et averti de leur existence
Le présent document remplace l’EN 1673:2000+A1:2009.
Les modifications significatives par rapport à l'édition précédente EN 1673:2000+A1:2009 de l’édition EN 1673:2000 sont énumérées ci-dessous :
- mise à jour de la liste des phénomènes dangereux significatifs et déplacement des zones dangereuses dans une nouvelle Annexe C informative ;
- révision des prescriptions de sécurité par rapport à la nouvelle liste des phénomènes dangereux significatifs (émission de vapeur, surfaces chaudes, etc.) ;
- ajout d’un nouveau paragraphe relatif aux aspects environnementaux ;
- révision de l’Annexe ZA pour mise en conformité avec la recommandation de la Commission Européenne.
Le présent document a été élaboré dans le cadre d'une demande de normalisation donnée au CEN par la Commission Européenne et l'Association Européenne de Libre Echange et vient à l'appui des exigences essentielles de la Directive UE 2006/42/CE.
Pour la relation avec la Directive UE 2006/42/CE, voir l'annexe ZA, informative, qui fait partie intégrante du présent document.
Selon le Règlement Intérieur du CEN-CENELEC les instituts de normalisation nationaux des pays suivants sont tenus de mettre cette Norme européenne en application : Allemagne, Ancienne République Yougoslave de Macédoine, Autriche, Belgique, Bulgarie, Chypre, Croatie, Danemark, Espagne, Estonie, Finlande, France, Grèce, Hongrie, Irlande, Islande, Italie, Lettonie, Lituanie, Luxembourg, Malte, Norvège, Pays-Bas, Pologne, Portugal, République Tchèque, Roumanie, Royaume-Uni, Serbie, Slovaquie, Slovénie, Suède, Suisse et Turquie.

Stroji za predelavo hrane - Peči z vrtljivim vozičkom - Varnostne in higienske zahteve

General Information

Status
Published
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
02-Dec-2020
Completion Date
02-Dec-2020

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SLOVENSKI STANDARD
SIST EN 1673:2021
01-februar-2021
Nadomešča:
SIST EN 1673:2002+A1:2010
Stroji za predelavo hrane - Peči z vrtljivim vozičkom - Varnostne in higienske
zahteve
Food processing machinery - Rotary rack ovens - Safety and hygiene requirements

Nahrungsmittelmaschinen - Stikken-Backöfen - Sicherheits- und Hygieneanforderungen

Machines pour les produits alimentaires - Fours à chariot rotatif - Prescriptions relative à

la sécurité et l'hygiène
Ta slovenski standard je istoveten z: EN 1673:2020
ICS:
67.260 Tovarne in oprema za živilsko Plants and equipment for the
industrijo food industry
97.040.20 Štedilniki, delovni pulti, Cooking ranges, working
pečice in podobni aparati tables, ovens and similar
appliances
SIST EN 1673:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 1673:2021
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SIST EN 1673:2021
EN 1673
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2020
EUROPÄISCHE NORM
ICS 67.260; 97.040.20 Supersedes EN 1673:2000+A1:2009
English Version
Food processing machinery - Rotary rack ovens - Safety
and hygiene requirements

Machines pour les produits alimentaires - Fours à Nahrungsmittelmaschinen - Stikken-Backöfen -

chariot rotatif - Prescriptions relative à la sécurité et Sicherheits- und Hygieneanforderungen

l'hygiène
This European Standard was approved by CEN on 2 November 2020.

CEN 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 CEN-CENELEC Management Centre or to any CEN

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 CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1673:2020 E

worldwide for CEN national Members.
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SIST EN 1673:2021
EN 1673:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms, definitions and classification ....................................................................................................... 7

3.1 Terms and definitions ................................................................................................................................... 7

3.2 Description ........................................................................................................................................................ 8

4 Safety and hygiene requirements and/or protective measures .................................................... 9

4.1 General ................................................................................................................................................................ 9

4.2 Mechanical hazards ..................................................................................................................................... 10

4.2.1 Zone 1: Drive mechanism .......................................................................................................................... 10

4.2.2 Zone 2: Mechanical parts in movement inside the baking chamber ......................................... 10

4.2.3 Zone 2: Space between the rack and any baking chamber door frame .................................... 11

4.2.4 Zone 4: Area in the front of any baking chamber door ................................................................... 11

4.2.5 Loss of stability ............................................................................................................................................. 11

4.3 Electrical hazards ......................................................................................................................................... 14

4.4 Thermal hazards .......................................................................................................................................... 14

4.4.1 Escape of steam by opening any baking chamber door ................................................................. 14

4.4.2 Hot external surfaces .................................................................................................................................. 14

4.4.3 Fire hazards due to overheating ............................................................................................................. 16

4.5 Hazard from being trapped inside the baking chamber ................................................................ 16

4.6 Hazards from remote control .................................................................................................................. 17

4.7 Hazards from automatic start and/or unexpected start and process restart ........................ 17

4.8 Hygiene requirements ................................................................................................................................ 17

4.8.1 General ............................................................................................................................................................. 17

4.8.2 Food area ......................................................................................................................................................... 17

4.8.3 Non-food area ................................................................................................................................................ 17

4.9 Hazards generated by neglecting ergonomic principles ............................................................... 18

5 Verification of the safety and hygiene requirements and/or measures .................................. 18

6 Information for use ..................................................................................................................................... 20

6.1 General ............................................................................................................................................................. 20

6.2 Information and warnings on the machine ........................................................................................ 20

6.3 Instruction handbook ................................................................................................................................. 21

6.4 Marking ............................................................................................................................................................ 22

7 Environmental aspects ............................................................................................................................... 23

Annex A (normative) Force measurement method ...................................................................................... 24

A.1 General ............................................................................................................................................................. 24

A.2 Measuring instrumentation ..................................................................................................................... 24

A.3 Method of measurement ............................................................................................................................ 24

Annex B (normative) Calculation of the kinetic energy .............................................................................. 25

B.1 Data ................................................................................................................................................................... 25

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EN 1673:2020 (E)

B.2 Calculation....................................................................................................................................................... 25

Annex C (informative) List of significant hazards .......................................................................................... 26

Annex ZA (informative) Relationship between this European Standard and the essential

requirements of Directive 2006/42/EC aimed to be covered ...................................................... 29

Bibliography ................................................................................................................................................................. 32

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SIST EN 1673:2021
EN 1673:2020 (E)
European foreword

This document (EN 1673:2020) has been prepared by Technical Committee CEN/TC 153 “Machinery

intended for use with foodstuffs and feed”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by June 2021, and conflicting national standards shall be

withdrawn at the latest by June 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 1673:2000+A1:2009.

The significant changes with respect to the previous version EN 1673:2000+A1:2009 of edition

EN 1673:2000 are listed below:

— upgraded list of significant hazards and danger zones removed in a new informative Annex C;

— safety requirements were revised with regard to the new list of significant hazards (steam emission,

hot surfaces, etc.);
— new clause regarding environmental aspects;
— Annex ZA was revised to be in line with European Commission recommendation.

This document has been prepared under a standardization request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of

EU Directive 2006/42/EC.

For relationship with EU Directive 2006/42/EC, see informative Annex ZA, which is an integral part of

this document.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,

Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,

Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North

Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United

Kingdom.
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SIST EN 1673:2021
EN 1673:2020 (E)
Introduction
This document is a type-C standard as stated in EN ISO 12100:2010.

This document is of relevance, in particular, for the following stakeholder groups representing the market

players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises);

— health and safety bodies (regulators, accident prevention organizations, market surveillance etc.).

Others can be affected by the level of machinery safety achieved with the means of the document by the

above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);

— machine users/employees (e.g. trade unions, organizations for people with special needs);

— service providers, e.g. for maintenance (small, medium and large enterprises);
— consumers (in case of machinery intended for use by consumers).

The above-mentioned stakeholder groups have been given the possibility to participate at the drafting

process of this document. The machinery concerned and the extent to which hazards, hazardous

situations or hazardous events are covered are indicated in the Scope of this document.

When requirements of this type-C standard are different from those which are stated in type-A- or type-

B-standards, the requirements of this type-C-standard take precedence over the requirements of the

other standards for machines that have been designed and built according to the requirements of this

type-C-standard.
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SIST EN 1673:2021
EN 1673:2020 (E)
1 Scope

This document specifies safety and hygiene requirements for the design and manufacture of rotary rack

ovens which can be used with one or more mobile racks.

These ovens are intended for professional use in the food industry and workshops (bakeries, pastry-

making, etc.) for the batch baking of foodstuffs containing flour, water and other ingredients and/or

additives. This document applies to ovens used only for food products except for those containing volatile

flammable ingredients (volatile organic compound, e.g. alcohol, oil, …). This document applies to ovens

where the steam is generated by an evaporation process of drinking water on hot surfaces.

The following machines are excluded:
— experimental and testing machines under development by the manufacturer;
— machines for non-professional uses.

NOTE Due to the fact that rotary rack ovens are intended for professional uses, EN 60335-1 and EN 60335-2-

42 are not applicable.

This document covers the technical safety requirements for the transport, installation, operation,

cleaning and maintenance of these machines (see EN ISO 12100:2010, Clause 6).

This document deals with all significant hazards, hazardous situations and events relevant to rotary rack

ovens when they are used as intended and under conditions of misuse which are reasonably foreseeable

by the manufacturer (see informative Annex C).
The following hazards are not covered by this document:
— hazards from the use of gaseous fuel by gas appliances;
— hazards arising from electromagnetic compatibility issues;
— hazards from the use of trays made of or coated by silicone;
— hazards due to dismantling, disabling and scrapping.
This document does not deal with noise emitted by the machine.

This document is not applicable to rotary rack ovens which were manufactured before the date of its

publication as an EN.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 203-2-2:2006, Gas heated catering equipment - Part 2-2: Specific requirements - Ovens

EN 614-1:2006+A1:2009, Safety of machinery - Ergonomic design principles - Part 1: Terminology and

general principles
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SIST EN 1673:2021
EN 1673:2020 (E)

EN 1005-3:2002+A1:2008, Safety of machinery - Human physical performance - Part 3: Recommended

force limits for machinery operation

EN 1672-2:2005+A1:2009, Food processing machinery - Basic concepts - Part 2: Hygiene requirements

EN 60204-1:2006, Safety of machinery - Electrical equipment of machines - Part 1: General requirements

(IEC 60204:2005, modified)

EN ISO 12100:2010, Safety of machinery - General principles for design - Risk assessment and risk reduction

(ISO 12100:2010)

EN ISO 13732-1:2008, Ergonomics of the thermal environment - Methods for the assessment of human

responses to contact with surfaces - Part 1: Hot surfaces (ISO 13732-1:2006)

EN ISO 13849-1:2015, Safety of machinery - Safety-related parts of control systems - Part 1: General

principles for design (ISO 13849-1:2015)

EN ISO 13857:2019, Safety of machinery - Safety distances to prevent hazard zones being reached by upper

and lower limbs (ISO 13857:2019)

EN ISO 14119:2013, Safety of machinery - Interlocking devices associated with guards - Principles for

design and selection (ISO 14119:2013)

EN ISO 14120:2015, Safety of machinery - Guards - General requirements for the design and construction

of fixed and movable guards (ISO 14120:2015)

EN ISO 21469:2006, Safety of machinery - Lubricants with incidental product contact - Hygiene

requirements (ISO 21469:2006)
3 Terms, definitions and classification
3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in EN ISO 12100:2010 and the

following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO online browsing platform: available at https://www.iso.org/obp
3.1.1
overpressure

positive difference between the pressure in the baking chamber and the pressure in the room where the

oven operates
3.1.2
steam generator

system which generates steam through the evaporation process of drinking water on hot surfaces

3.1.3
baking chamber

space where the baking process is carried out, including the frame of every baking chamber door

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SIST EN 1673:2021
EN 1673:2020 (E)
3.1.4
baking chamber door
movable guard which shall be open for introducing a rack into the baking chamber
3.1.5
process restart
starting after a stoppage:
a) during a baking cycle execution;
b) between two baking cycles without changing anything in the baking process;

c) after the end of the baking cycle only for maintaining the temperature level in the baking chamber

3.2 Description
A rotary rack oven usually consists of the following parts (see Figure 1):
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SIST EN 1673:2021
EN 1673:2020 (E)
Key
a container built with insulated panels
b baking chamber
c heat production unit
d hot air circulation system
e rack
f trays
g drive unit for rack rotation
h steam generator
i steam extractor
j control panel

k miscellaneous devices (e.g. combustion product flue where gas or fuel fired) (optional)

l device to hold and/or rotate the removable rotary racks
m baking chamber door
n loading area
o internal handle
NOTE Rack (e) and trays (f) are either provided by the manufacturer or the user.
Figure 1 — Example of parts of a rotary rack oven
4 Safety and hygiene requirements and/or protective measures
4.1 General

Machinery shall comply with the safety requirements and/or protective measures of this clause.

In addition, the machine shall be designed according to the principles of EN ISO 12100:2010 for relevant

but not significant hazards, which are not dealt with by this document.
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SIST EN 1673:2021
EN 1673:2020 (E)

Every electrical control circuits with safety functions shall meet at least a performance level “c” defined

in accordance with EN ISO 13849-1:2015, unless it is differently specified in this document.

When fixed guards, or parts of the machine acting as such, are not permanently fixed, e.g. by welding,

their fixing systems shall remain attached to the guards or to the machinery when the guards are

removed.

A normal stop device shall be provided, and it shall control a stop of category 1 according to

EN 60204-1:2006, 9.2.2, except the normal stop controlled by releasing a hold-to-run control which shall

be category 0.

No emergency stop is required unless it is differently specified in this document.

Where reference is made to interlocking guards, the associated interlocking devices shall comply with

EN ISO 14119:2013. If an interlocking device type 2 or type 4, as defined in EN ISO 14119:2013, is used

it can be of low level provided that the requested PL is achieved.
4.2 Mechanical hazards
4.2.1 Zone 1: Drive mechanism

Access to the transmission parts outside of the baking chamber shall be prevented by:

a) fixed enclosing guards according to EN ISO 13857:2019 and EN ISO 14120:2015; and/or

b) distance guards according to EN ISO 13857:2019, Table 1, and EN ISO 14120:2015.

If there are openings in the guard, they shall comply with EN ISO 13857:2019, Table 3 and/or Table 4.

4.2.2 Zone 2: Mechanical parts in movement inside the baking chamber
4.2.2.1 General

To avoid any mechanical hazards due to the movement of the rack inside the oven, the following

requirements shall be apply:
a) Every baking chamber door shall be interlocked, except in case of 4.2.2.2;

b) The force to stop the rotating of the rack shall be ≤ 150 N and the energy required to stop the rotating

rack shall be ≤ 10 J. In this case, an emergency stop shall be provided and it shall be easily reachable

from any opening intended for the introduction of the rack in the baking chamber when the relevant

baking chamber door is open. The relevant control circuit shall meet at least a performance level “c”

defined in accordance with EN ISO 13849-1:2015

Where the driving force is provided by mechanical friction, the force to stop the rotating rack shall be

measured according to Annex A.

The energy required to stop the rotating rack shall be calculated according to Annex B.

Opening any interlocking baking chamber door shall activate the stop of the rack movement when the

opening clearance is not greater than 20 mm.
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EN 1673:2020 (E)

The stopping time of the device for providing the movement of the rack shall be less than or equal to 1 s,

when the protective device is actuated.
Access to the fan of the ventilator shall be prevented by:

a) fixed enclosing guards according to EN ISO 13857:2019 and EN ISO 14120:2015; and/or

b) distance guards according to EN ISO 13857:2019, Table 2, and EN ISO 14120:2015.

If there are openings in the guard, they shall comply with EN ISO 13857:2019, Table 3 and/or Table 4.

For automatic lifting units, the lifting and unlifting movement shall be stopped when any baking chamber

door is open. Access to the automatic lifting system shall be prevented by the interlocked door(s) which

prevent access to the baking chamber while the drive mechanism of the rack rotation is running. Opening

any interlocking baking chamber door shall activate the stop of the rack movement when the opening

clearance is not greater than 20 mm.

The stopping time of the device for providing the lifting and unlifting movement of the rack shall be less

than or equal to 1 s when the protective device is actuated.

Process restart, which can include lifting and unlifting of the rack, shall only be possible by actuating the

starting or – if existing – process restart control (see 4.7).
4.2.2.2 Adjusting of the rack position under power

Any operation which requires the rack to rotate under power while any baking chamber door is open

shall be controlled exclusively by a hold-to-run control located near the relevant door for a maximum of

one turn. The maximum speed of the rack shall be 5 turns/min.
4.2.3 Zone 2: Space between the rack and any baking chamber door frame

To prevent hand injury when introducing and extracting the rack in/from the oven, the width of the

passage opening when any baking chamber door is completely open shall be at least 100 mm larger than

the width of the largest rack indicated in the instruction handbook (see 6.3).
4.2.4 Zone 4: Area in the front of any baking chamber door

To prevent the unintended opening of any baking chamber door of the baking chamber due to

overpressure inside the baking chamber, an exhaust duct shall be installed which limits the overpressure.

The pushing force against any baking chamber door generated by the overpressure shall not exceed

500 N.

The manufacturer shall provide instructions about the method and the frequency for exhaust duct

inspection and maintenance (see 6.3).
4.2.5 Loss of stability
4.2.5.1 Stability of the rack during the rotation

To prevent overturning of the rack during rotation and engaging/disengaging of the rack with/from

rotation system, one of the solutions shown in Figure 2 shall be adopted.

In Figure 2 a), the rack is manually pushed onto the rotating platform and locked for instance by means

of springs.
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EN 1673:2020 (E)

In Figure 2 b), the rack is manually pushed onto the rotation system hook and lifted off the ground by the

inclined surface of the hook. The rack shall remain stable during rotation on the oven floor. This may be

achieved by a coupling at its axis of rotation or by other means (e.g by pincers, jaws).

In Figure 2 c), the rack is pushed into the rotation system and lifted by means of a power-driven

mechanism.
a) Rotating platform with ramp b) Rotating system lift hook

The rack is manually pushed onto the rotating The rack is manually engaged and lifted onto the

platform. rotating system.
c) Automatic lifting unit

Figure 2 — Solutions for engaging/disengaging of the rack with/from rotation system

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EN 1673:2020 (E)
4.2.5.2 Stability of the rack entering the baking chamber

To prevent the rack overturning on entering the oven, a ramp shall be provided if the difference in level

exceeds 10 mm. The ramp shall be designed in such a way that the inclination of the rack does not

exceed 7° while entering or leaving the oven with respect to the horizontal plane in any condition.

However, the angle of the ramp with respect to the horizontal plane shall not exceed 10°.

4.2.5.3 Stability of rack and trays standing outside the baking chamber
The stability of the rack can be checked by one of the following methods:

1) by practical test: the empty rack (without trays) shall not overturn when it is tilted by more than 7°

with respect to the horizontal plane in the most unfavourable position and with wheels positioned

as shown in Figure 3 and locked.

2) by calculation: calculate the position of the centre of gravity and check that its horizontal projection

is inside the supporting point of the rack when it is tilted by 7° in the most unfavourable position.

When racks are supplied by the manufacturer, the design shall prevent accidental displacement of the

trays, during loading and unloading of the oven. Trays shall be secured in the rack (e.g by means of

mechanical stops at the end of the tray support of the rack as shown in Figure 3). When racks are not

supplied by the manufacturer, the manufacturer shall give information in the instruction handbook about

the racks which can be used in the oven (see 6.3).
Key
1 example of mechanical stops for the trays
Figure 3 — Conditions for the stability test
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SIST EN 1673:2021
EN 1673:2020 (E)
4.3 Electrical hazards

The electrical equipment shall comply with EN 60204-1:2006. According to EN 60204-1:2006, 18.1, tests

a), b), c), d) and f) shall be carried out to machine distribution board.
4.4 Thermal hazards
4.4.1 Escape of steam by opening any baking chamber door

Escape of steam by opening any baking chamber door shall be minimized by suitable means, for example

by an extractor running when opening any baking chamber door, evacuation of the steam before the end

of the baking.

A steam emission symbol warning shall be affixed at the outside of every baking chamber door (see 6.1).

When opening any baking chamber door:

— the water feeding device to produce steam shall be switched off automatically; a performance level

for all relevant circuits is not required;

— the air circulation inside the baking chamber shall be switched off automatically.

4.4.2 Hot external surfaces

To prevent injury from hot external surfaces, the oven shall be provided with insulation so that the

temperature of front surfaces does not exceed:
— 70 °C for uncoated metal surfaces;
— 85 °C for glass surfaces;
— 90 °C for plastic surfaces.
For other materials, see EN ISO 13732-1:2008.

External crank handles, handles and similar manual controls which in ordinary use are held in the hand

for more than 4 s, shall not exceed the temperature limit value of:
— 58 °C for an uncoated metal handle;
— 70 °C for a glass or ceramic handle;
— 75 °C for a plastic handle.
For other materials, see EN ISO 13732-1:2008.

Figure 4 gives the temperature threshold for handle surfaces and for external surfaces of the ovens.

...

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