IEC 60335-2-89:2010/ISH1:2014

Interpretation sheet 1 - Household and similar electrical appliances - Safety - Part 2-89: Particular requirements for commercial refrigerating appliances with an incorporated or remote refrigerant unit or compressor

Feuille d'interprétation 1 - Appareils électrodomestiques et analogues - Sécurité - Partie 2-89: Règles particulières pour les appareils de réfrigération à usage commercial avec une unité de fluide frigorigène ou un compresseur incorporés ou à distance

General Information

• Status: Published
• Publication Date: 09-Jul-2014
• ICS: 97.130.20 - Commercial refrigerating appliances
• Technical Committee: SC 61C - Safety of refrigeration appliances for household and commercial use
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 20-Jun-2019

Relations

• Revised: IEC 60335-2-89:2019 - Household and similar electrical appliances - Safety - Part 2-89: Particular requirements for commercial refrigerating appliances and ice-makers with an incorporated or remote refrigerant unit or motor-compressor
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-89:2010 - Household and similar electrical appliances - Safety - Part 2-89: Particular requirements for commercial refrigerating appliances with an incorporated or remote refrigerant unit or compressor
• Effective Date: 05-Sep-2023

Standards Content (Sample)

SC 61C/IEC 60335-2-89 (2010), second edition/I-SH 01

HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES – SAFETY –

Part 2-89: Particular requirements for commercial refrigerating appliances

with an incorporated or remote refrigerant unit or compressor

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by subcommittee 61C: Safety of refrigeration
appliances for household and commercial use, of technical committee 61: Safety of household
and similar electrical appliances
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
61C/562/ISH 61C/571/RVISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
SC 61C interpretation sheet on: Pressure relief devices used in transcritical
refrigeration systems
Introduction
Requirements for refrigeration systems that use transcritical refrigerants such as CO (R 744)
were introduced into the standard in 2010; however at the time few manufacturers saw
transcritical refrigerants as a future progression. It is only recently that commercial
refrigerating appliances using such systems are being developed and as a result some
clarification of the standard is required due to practicalities of technology being applied.
There is a requirement in 22.103 that appliances employing a transcritical refrigeration

system shall include a pressure relief device in the high pressure side of the refrigeration
system. The intent of this device is to prevent the pressure of the system exceeding the
design pressure should a malfunction occur, such as a failure of the gas cooler fan motor.
A pressure test is carried out on the system with the pressure relief device rendered
inoperative to ensure that the high side of the system and components can withstand at least
3 times the design pressure or as a minimum the high side pressure specified in
IEC 60335-2-34, which in the case of R 744 (CO ) is 420 bar (42 MPa).
The pressure relief device is defined in 3.111 as a “pressure sensing device intended to
reduce pressure automatically when pressures within the refrigeration system exceed the
setting pressure of the device”.
As per the text of 22.103 the operating pressure of the pressure relief device shall be no
higher than the design pressure of the high pressure side. The component test parameters
for several different types of pressure relief device such as mechanical, electrical and those
of the burst disc type are listed in the addition of 24.1.4.

Questions
On the basis that the pressure relief device can maintain the design pressure by either

venting refrigerant from the refrigeration system or by automatically shutting down the

pressure generating element (the compressor),

1) How to apply the second paragraph of 22.103 where the pressure is controlled by

automatically shutting down the pressure generating element (the compressor).

2) Subclause 24.101 specifies requirements to ensure that the discharge capacity of the

pressure relief device is adequate and which can be verified by calculation or by a

test. In the case of an electrical pressure relief device that automatically shuts down
the compressor instead of externally venting refrigerant is this clause relevant?
Relevant text from IEC 60335-2-89:
The second paragraph of 22.103 states in regard to the mounting of the pressure relief
device: “The pressure relief device shall be mounted so that the refrigerant released from
the system cannot cause any harm to the user of the appliance. The aperture shall be located
so that it is unlikely to be obstructed in normal use.”
Subclause 24.101 states:
24.101 The discharge capacity of the pressure relief device shall be such that it is able to
release an adequate amount of refrigerant so that the pressure during the release of the
refrigerant does not increase beyond the pressure setting of the pressure relief device, even
if the compressor is operating.
Compliance is checked by validation of the manufacturer’s calculations or by an appropriate
test.
ANSWERS
1) The second paragraph of 22.103 is not relevant where the pressure is controlled by
automatically shutting down the pressure generating element (the compressor) since
the pressure is not controlled by releasing refrigerant from the system.
2) Subclause 24.101 is not relevant to a pressure relief device that senses pressure and
shuts down the compressor automatically if the system high side pressure exceeds the
high side design pressure since such a device does not have a discharge capacity.

July 2014 ICS 97.130.20
SC 61C/IEC 60335-2-89 (2010), deuxième édition/I-SH 01

APPAREILS ÉLECTRODOMESTIQUES ET ANALOGUES – SÉCURITÉ –

Partie 2-89: Règles particulières pour les appareils de réfrigération

à usage commercial avec une unité de fluide frigorigène ou

un compresseur incorporés ou à dis
...