The IEC working group revising the recommended hydrocarbon charge limit in commercial refrigeration within the IEC 60335-2-89 standard has decided to move to the next stage in the process.
During a meeting on 7 October in Vladivostok, International Electrotechnical Commission (IEC) Working Group SC61C – formed to update the international standard for commercial refrigeration, IEC 60335-2-89 – agreed to finalise its work and advance the draft amendment (committee draft for vote; CDV) for comments by national committee members within the IEC.
The draft amendment, which proposes to increase the propane charge limit to 500g, should become available for a review in December 2017. The proposed charge limit is based on 13 times the low flammability level (LFL) of propane. In order to ensure safety, the draft amendment will require a minimum room area where the system can be placed and it has to pass the leakage test that will show the relative absence of flammable concentrations around the system, besides other construction requirements.
The charge limit increase will cover all safety classes of flammable refrigerants, but with different limits.
Standards from the IEC, a worldwide body that proposes rules governing how to use electrical, electronic and related technologies, influence the development of the market by providing manufacturers and customers with guidelines as to what is safe to use and buy.
The present international standard for hermetically sealed commercial refrigeration equipment limits the use of flammable refrigerants to 150g. It is commonly accepted by experts that this limit does not allow manufacturers and end users to fully exploit the safe application of hydrocarbon refrigerants in this sector.
To address this, Working Group SC61C was created in 2015 with a view to raising the recommended charge limit for flammable refrigerants. After almost three years of intense work, the working group has now approved the proposed text to amend the IEC standard, marking an important step in the process of standards development. Nevertheless the amendment to the international standard that could raise the charge limit for propane to 500g is still a long way from being finalised.
Final standard expected in 2019
Once the working group completes the Committee Draft for Vote (CDV) it will be circulated for comments by national committee members within IEC in December 2017. A vote on the CDV is expected in the first half of 2018. Provided that more than two-thirds of the committee members vote in favour, the draft will go to the final vote phase (FDIS) by the end of 2018 following a committee meeting in Busan, South Korea in October 2018.
A new version of the IEC standard is expected at the beginning of 2019.