Since 2015, both local and international standards have been amended and this has created some confusion of the compliance requirements of low voltage switchgear. Switchgear is indispensable in the transmission of electricity to power consumers. Inadequate testing and/or the purchase of untested products can have dire consequences to the supply of electricity as a result of increased explosions or malfunctions of equipment.
The South African National Standards (SANS) that apply to switchgear have been adopted from the International Electrotechnical Commission (IEC). In October 2015, IEC standard 61439 replaced SANS 60439:2004, which was the standard that applied to low voltage switchgear and controlgear assemblies. The new standard allows for any one of the three types of design verification to indicate compliance to the standard (Verification by Type Testing, Verification by Calculation or Measurement, and Verification by Design Rules), whereas the previous standard required verification by testing without reference to all categories. While SABS adopted IEC 61439 as SANS/IEC 61439: 2015; for South African use, the testing requirements also need to include the Wiring Code SANS 10142-1:2017.
“Switchgear end users are faced with exploding switchgear or malfunctioning equipment as a result of increased temperature rise, and these scenarios can be drastically reduced through ensuring that switchgear is independently tested and verified through type testing. Verification by type testing subjects the equipment to performance limits or ‘destructive’ testing, functional tests and, most importantly, includes temperature rise tests for indoor and outdoor applications. Most manufacturers prefer to conduct verification by calculation or by design rules as this is cheaper and does not have to be conducted in a laboratory. The critical gap is that these tests exclude destructive testing of the equipment and testing to South African conditions,” says Garth Strachan, Acting CEO of SABS. SABS has held several consultative engagements with the electro-technical industry to raise the concerns of inadequate testing of switchgear.
In October 2018, SABS reintroduced partial testing or testing to customer specific requirements to enable type testing of switchgear. “Independent type testing of switchgear through accredited laboratories may be an additional expense for manufacturers; however, it will provide assurance to switchgear end users that the equipment is safe to use, can withstand South African climatic conditions, and is functional.
Switchgear end users are advised to review all the test reports provided by switchgear manufacturers to ensure the tests have been conducted by accredited laboratories and to ensure that type testing by a South African accredited laboratory is provided,” says Strachan. SABS, through its independent, third-party, National Electrical Test Facility (NETFA), which is accredited by the South African National Accreditation System (SANAS), is capable of conducting verification by type testing on a range of switchgear equipment.
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