IEC TR 63225:2019 pdf download

IEC TR 63225:2019 pdf download.Incompatibility of connectors for DC-application in photovoltaic systems
1 Scope
This document highlights the problem of incompatibility of connectors for DC-application in photovoltaic systems (DC connectors) produced by different manufacturers. It addresses four particular issues in that context: • background information on incompatibility of DC connectors from different manufacturers; • observations and challenges concerning the handling of DC connectors from different manufacturers; • stakeholders concerned by the incompatibility of DC connectors; • recommendations for long-term standardization and interim measures to address incompatibility of DC connectors.
2 Normative references
IEC 62852, Connectors for DC-application in photovoltaic systems – Safety requirements and tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62852 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 http://www.iso.org/obp 3.1 DC connector connector designed for use in DC circuits of photovoltaic systems, as defined in IEC 62852. Note 1 to entry: This document generally refers to connectors of type MC4 or similar, and particularly products that are often referred to as “MC4-compatible”. 3.2 compatible DC connectors interoperable DC connectors intermateable DC connectors <connector pair> components which terminate conductors for the purpose of providing connection to and disconnection from a suitable mating component under supervision of one quality management system
4 Background
In the early years of terrestrial photovoltaics, a range of different DC connectors were available on the market. They were of distinctly different designs and could not be connected between each other. In the early 2000s the connector type MC4 1 became more and more popular. Manufacturers started to adapt their connectors to the MC4 type. However, no international or consortia-based interface technical specifications for this connector type are available. IEC 62852, often referred to in this context, is a product safety standard and is not intended to test intermateability. Several countries report that problems with DC connectors are a major cause for failure such as fire hazards in PV systems. Reports from different testing laboratories have shown that DC connectors from different manufacturers may not be safe to interconnect. Even if they meet basic quality requirements in the short term, they may derate when connected to products from different manufacturers. Disregarding these circumstances, DC connectors are often declared by manufacturers as being compatible with each other. This claim of compatibility is potentially misleading as it suggests a safe interoperability of DC connectors from different manufacturers.IEC 61 730-1 tackles the safe electrical operation of PV modules, but does not tackle the topic of connecting DC connectors from different manufacturers. However, IEC 62548 and IEC 60364-7-71 2:201 7 are installation standards and they explicitly do not allow the connection of DC connectors from different manufacturers. IEC 62852 is not intended to be used for DC connectors produced by different manufacturers and does not guarantee long-term reliability of components from different quality management systems. Despite the explicit prohibitions in these International Standards, even installers aware of the dangers of using connectors from different manufacturers continue to do so since there are often insufficient available alternatives.These reasons often give the installer or system owner few choices but to assume the risks of mating connectors from different manufacturers and as a result several fire hazards caused by non-compatible DC connectors have been reported. Although a burnt connector leaves little evidence to ascertain the initiating root cause, connectors from different manufacturers are found to be a common factor. These observations are not new and multiple agencies have reported the problem. For several years, test laboratories have been reporting insufficient connection quality and reliability if DC connectors from different manufacturers are connected, and it can be assumed that the continuing connection between incompatible connectors will lead to an increasing number of fire hazards in future. Nevertheless, no satisfactory solution has been found yet to the problem of needing to use connectors from the same manufacturer, but not having easy supply of all connectors currently available on the market for use in the field.