Blackburn Starling first began manufacturing low voltage switchboards in the 1920s utilising DC switches & rheostats to control various types of equipment. Switchboards as we would recognise them today began commercial manufacture in the 1960s.
The earliest British Standard for this type of equipment was: -
BS4070:1966.The performance of AC control gear equipments rated up to 600V was published on the 1st January 1966.
Blackburn Starling first undertook ASTA Certification testing in 1975 & has continued to develop, improve & test its products to ensure compliance with the latest British & European Standard: – BS EN 61439-1:2011, Low-voltage switchgear & control gear assemblies Part 1: General Rules.
Short Circuit Tests on our assemblies cover the following ranges: -
|Icw Ph – Ph rms||Icw Ph – N rms||Ipk Peak current|
|25kA for 1s||16kA for 1s||52.5kA|
|43kA for 3s||25kA for 3s||112kA|
|50kA for 1s||30kA for 1s||105kA|
|50kA for 3s||30kA for 3s||105kA|
|71kA for 1s||43kA for 1s||156kA|
|80kA for 1s||48kA for 1s||176 / 200kA|
|100kA for 1s||60kA for 1s||220kA|
Short Circuit tests on the Protective Conductor cover the following ranges: -
|Icw Ph – PE rms||Ipk Peak current|
|60kA for 1s||132kA|
|48kA for 1s||101kA|
|30kA for 1s||63kA|
These tests have been performed on a range of HDHC copper busbar systems with sizes ranging from 25.4 x 6.35mm to 200 x 10mm, (400A to 6300A) with the maximum number of laminations being three per phase.
In the 1970 & 80s we also conducted tests on fuse / contactor / overload combinations to prove compliance to Type C co-ordination @ 415V. In more recent times the manufacturers’ of the components conduct these tests to prove Type 2 co-ordination to BS EN 60947, at various voltage levels (380, 400, 440V etc).
The busbar systems & enclosures are Blackburn Starling’s own design & manufacture, these have been tested as complete units. This ensures the tests are performed on a “complete assembled unit” as would be supplied to a customer.
The tests are carried out using one set of busbar supports, so they are made to withstand several fault conditions. This is beyond the requirements of the standard which allows for the busbar supports to be changed after each successive test.
On completion of the Fault Testing each assembly was subjected to a di-electric test of 2500 Volts for 60 seconds. We have also conducted this test at 3500V for 60 seconds without any detriment to the equipment.
This combination of tests & HDHC copper busbar ranges enables Blackburn Starling to offer a product to suit most applications required across industry i.e. offering a Type Tested Assembly in relation to the Short Circuit rating.
In order to demonstrate compliance with BS EN 61439-1:2011, Section 10.1 details 2 lists of areas to be reviewed under the heading
Design verification shall comprise the following: -.
10.2 Strength of materials & parts
10.3 Degree of protection of enclosures
10.4 Clearance & creepage distances
10.5 Protection against electric shock & integrity of protective circuits
10.6 Incorporation of switching devices & components
10.7 Internal electrical circuits & connections
10.8 Terminals for external conductors
10.9 Dielectric properties
10.10 Verification of temperature rise
10.11 Short-circuit withstand strength
10.12 Electromagnetic compatibility
10.13 Mechanical operation
This is also covered in ANNEX D, Table D.1
The following tests have all been verified by an independent Association, such as ASTA or TUV.
10.2, 10.3, 10.4, 10.5, 10.6, 10.9, 10.11,
The following tests have been verified by in-house testing.
10.7, 10.8, 10.10, 10.12, 10.13
Test 10.13 is verified by the Manufacturer of the Products utilised & is repeated by Blackburn Starling to ensure it is correctly integrated within our equipment.
Routine verification tests are listed in Section 11.1, under the heading
Verification shall comprise the following categories: -
a) Construction (see 11.2 too 11.8):
1 Degree of protection of enclosures
2 Clearance & creepage distances
3 Protection against electric shock & integrity of protective circuits
4 Incorporation of switching devices & components
5 Internal electrical circuits & connections
6 Terminals for external conductors
7 Mechanical operation
b) Performance (see 11.9 to 11.10):
1 Dielectric properties
2 wiring, operational performance & function
All equipment, upon completion in the factory, is subjected to the above mentioned tests in the presence of the customer. Insulation tests are performed in excess of the BS requirements, typically 2200V for 60s (the requirement is 1s).
Blackburn Starling will issue a copy of Annex C (Annex BB of BS EN 61439-2) on receipt of an order to ensure that the correct design information is available from the contractor & this will form an important part of the design verification process & Technical File. All the design information is held in both the Contract file & the Technical Information Files which are made available to the customer as required. These files are reviewed by the customer during the inspection & we provide a set of certificates confirming compliance of the products as a TTA.
Temperature-rise details are dependant upon the equipment installed within the switchboards. Information is provided by the component supplier & tests undertaken have verified compliance to the relevant British / European Standards. The company has established a knowledge base which provides a reference list of watts loss per compartment size/volume & section for various sizes & type of product.
Each switchboard layout is arranged to suit the customer load requirements, then checked to ensure each sections heat loss does not exceed our reference list. This information is checked during the design verification procedure & is maintained in our Technical Information File. The switchboard layout is signed off by the Technical Director or Chief Electrical Engineer.
The temperature rise tests have been performed using load banks & heaters to simulate component losses. The test records are available for review.
When installing equipment, such as variable speed drives the heat loss on these types of units require additional ventilation requirements & these are defined by the manufacturer of the product. This detail includes the heat loss & the required air flow (m3/h) through the device. We ensure that all our equipment is fitted with externally mounted IP54 fans (& filters) with the same or increased airflow than that required by the manufacturer.
Our switchboards have been subjected to Independent Test for Degree of Protection at IP54. This test was performed in accordance with BS EN 60529, Clause 13.4, Category 1 (with a partial vacuum). This test is in excess of the requirements for BS EN 60349-1 which only requires Category 2 (no partial vacuum) for all product rated IP5x.