Introduction to 61439-1

Key Issues and Challenges Associated with the introduction of BS EN 61439-1

BS EN 61439-1 and 61439-2:2011 incorporates several changes from the previous standard. Blackburn Starling has implemented these changes and is able to offer a product which complies with these new standards. Verification of various alternatives / options (e.g. withdrawable) is ongoing.

The verification has been split in to 2 sections, 1 covering Construction and 1 covering Performance, the clauses below refer to those in BS EN 61493-1.

The issues pertaining to Blackburn Starling and the product we manufacture are listed below, of which 3 are related to construction (C) and 1 to performance (P), in all other aspects our existing product complies with the latest standard: -

C – Clause 10.2.2 – Resistance to Corrosion
C – Clause 10.2.3.3 – Verification of resistance of insulating material to abnormal heat and fire due to internal electrical effects.
C – Clause 10.2.5 – Lifting
P – Clause 10.10 – Verification of temperature rise.

Implementation / Progress

Clause 10.2.2 – Resistance to Corrosion.
Blackburn Starling has conducted tests at an independent laboratory to verify our compliance with this clause under Severity A – which is applicable to metallic indoor enclosures. This test was performed on a typical MCC enclosure, ensuring all manufacturing and assembly aspects were included – door hinges, locks, seals, fasteners, etc. were fitted as standard.

Clause 10.2.3.3 – Verification of resistance of insulating material to abnormal heat and fire due to internal electrical effects.
Blackburn Starling already utilise materials providing insulation and shrouding within our MCCs in order to comply with this clause. The requirements are that any insulation material used to support current carrying parts must be able to withstand a glow-wire test at 960oC. All other parts (e.g. those used to shroud live parts) are able to withstand 650oC.

Several customers are now requesting the installation of fire barriers between sections and the material used here is a GP-03 Product, which has a V0 rating in accordance with UL94 (for a thickness of =/> 2.4mm). Based on this and for flexibility of manufacture Blackburn Starling is utilising this product in more areas of the construction / assembly as it is readily identifiable by its RED colouring.

Clause 10.2.5 – Lifting.
Tests are required at 1.25 times the maximum shipping weight. All MCCs differ in arrangement and weight when being shipped due to the configuration of the circuits. Blackburn Starling uses a combination of lifting eyes and beams when lifting and transporting panels to and around a site. Certification tests have been performed on the lifting beams that we manufacture; these can be reviewed during CFAT and prior to despatch.

The weight of individual sections to be lifted varies from 350kg to 1500kg and this defines whether lifting eyes or lifting beams are used. The lifting eyes we use are made from Stainless Steel grade A4, size M18 and come with a Test Certificate. During loading at the factory they are fitted to the panel and remain in place until the panel is off loaded / installed at site where they are removed and returned to base. We have 100 lifting eyes held in a 2 rack system, each time an eye is used it is returned to the lower rack, once all the eyes from the top rack are used the racks are swapped over – this ensures rotation of all the lifting eyes on an even basis during the year. The lifting eyes are checked / verified annually by an independent company. Any damaged units are disposed of and replacements purchased.

In accordance with the details of this clause, the actual lifts we have performed on site do represent these sequences: -

panels have been moved horizontally, via a crane, for a distance greater than that listed below.
panels have been suspended on cranes whilst lifting into multi-storey buildings, this has exceeded 30 minutes on more than 1 occasion
and the lifting devices have been proof load tested at a SWL of 1.25X.

To ensure that our lifting methods and procedures are compliant we have conducted independent tests on sample products covering the areas listed in this clause;

Lift to a height of 1 ±0.1m
Repeat a further 2 times
Raise and then suspend for 30mins without movement
Raise and then move 10 ±0.5m horizontally
Repeat twice more – 3 tests at 1min intervals.

Clause 10.10 – Verification of temperature rise.
Three methods have been detailed as to how verification can be made;
Blackburn Starling has undertaken these tests with load and simulation via heaters to produce its reference tables. Extrapolation is then used for MCC’s whose rating does not exceed 1600A (clause 10.10.4.3) in accordance with IEC 60890.

The details in BS EN 61439-1:2011, Annex E, define several scenarios for testing equipment based on the ratings / arrangement of load circuits and the incoming ACB.
In each of these scenarios the load circuits are rated at the design diversity factor per Table 101 (BSEN 61439-2:2011), but the incoming circuit breaker is always shown at 100% of it nominal rating.

Based on this, Blackburn Starling has conducted tests on 1600A, 3200A and 4000A ACB’s in various Switchboard configurations, the load current through the ACB was 100% nominal rating and the load through the outgoing circuits, collectively was between 0.6 and 1.0 diversity, these certificates and details of the tests can be reviewed by the customer upon request or at time of CFAT.

During these tests we have established a watt loss for various compartment sizes in relation to the other compartments within the assembly.

Based on this and in accordance with Clause 10.10.3 we used this data to verify other compartments or change of component suppliers,

a) provided the compartment dimensions are the same or greater than tested
b) provided the component watts loss is the same as or less than that tested.

Future development for BS EN 61439-1:2011 and -2:2011 will include additional tests as required by product development or by customer requests.

Based on the above we can provide certificates covering the Construction and Performance listed in Clause 10.1 to show our compliance to BS EN 61439-1:2011 and -2:2011.

In summary,

1) Blackburn Starling considers itself to be compliant with BSEN 61439-1 and BSEN 61439 -2.

2) Blackburn Starling will undertake further independent tests as required by product development or by customer requests.

3) Blackburn Starling will continue with temperature rise tests using loads and simulations to extend the range already covered and develop our knowledge base of losses as our scope of supply extends to bus bar ratings of 6300A.

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