The new standards IEC and IEC replaced the previous standard IEC is a product standard which defines the specific requirements. date BS EN is withdrawn and BS EN and BS EN should be used. Since the publication of IEC other parts of the series. – The new standard. IEC Relationship between the two standards is as shown in the table below: IEC replaces. IEC
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Purchase your copy of BS EN as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards. assemblies to IEC and when ratified BS EN on the only routine tested, is no longer an option as it was under BS EN chausifetonis.ml UserFiles/file/downloads/assessment/Beama%20Guide%pdf. Add to Cart. Printed Edition + PDF; Immediate download; $; Add to Cart Replaces BS EN which remains current.
PSC-assemblies can be divided to attain one or more of the following conditions between functional units, separate compartments or enclosed protected spaces: - protection against contact with hazardous parts.
Separation may be achieved by means of partitions or barriers metallic or non-metallic , insulation of live parts or the integral housing of a device e. So, to satisfy the main criteria for Form 4, one alternative is to merely use an MCCB which by definition has a moulded case enclosing the electrical and mechanical parts necessary for it to fulfil its function. In this case, the terminal compartment may also physically form one of the constructional elements of the MCCB device.
To effect this arrangement, a means of shrouding the terminals and connected cable glands to ensure a minimum of IPXXB is necessary.
Form 4 Type 5 indicates this may be done by use of insulated coverings. Forms 4 Type 6 and Type 7 require the separation via metallic or non-metallic rigid barriers or partitions.
So, again, a suitably designed MCCB device can satisfy both the main criteria, for Form 4 and the sub-criteria for Form 4b, and depending on the materials used to form the termination chamber, can provide Form 4 Type 5 or 6 arrangements. One key issue to note is neutral N conductors, as they contribute to the fulfilment of the same function, form part of a particular functional unit and, in respect of Forms of Separation, must be treated as part of the functional unit.
To this end, each outgoing way must have its own individual N connection, usually alongside the phase connections, and not be connected at a common N bar or terminal. It is usual for a triple pole MCCB, for example, to have a separable neutral link mounted immediately adjacent to the MCCB to allow connection of all external cables in the same protected space, assuming adequate shrouding of all four terminals.
A common N termination point arrangement cannot be deemed to be Form 4 as there is no separation of the terminals for external N connections for each functional unit in this case. Both can be declared Form 4 separation and both meet the performance requirements for separation. However, separation is not the only criterion to be considered.
This paper provides feedback on our experiences with the new standards so far. Significant changes Firstly, we should be reminded of the most significant technical differences between the old and new standards. This initially appeared to reduce the requirements for actual testing.
The verification tests described in IEC confirm the reference design from which subsequent configurations may be verified by the alternative methods described. However, the introduction www.
IEC also covers common questions such as: manufacture at alternative premises and substitution of alternative functional components. The actual requirements of most of the tests are very similar and some testing to IEC may fulfil the requirements of IEC However, the most significant difference is for the temperature rise testing which introduces three possible methods of performing temperature rise tests: a Considering individual functional units separately plus the complete assembly including busbars b Considering functional units, main and distribution busbars and the assembly collectively.
The standard also requires the manufacturer to specify the method required, which is not the easiest of tasks, if you do not know the benefits of each method. Another quite significant change was the introduction of a new clause for Materials testing, tests which were not included in IEC They include corrosion resistance, properties of insulating materials, resistance to heat, resistance to UV radiation, lifting, mechanical impact and marking.
Other less significant changes were mechanical operations on built-in electromechanical devices instead of 50 and 5 positive and negative impulse tests instead of 3.
Therefore, providing that all parties read and understood the new standards, it was fairly straightforward, or, was it? Our experiences Many manufacturers in the preceding two years have still chosen to test to the old standard, knowing that their end user will still accept the certification. However, during , we have encouraged most of our clients to test to the new standard in preparation for non-acceptance of the old. Not all testing laboratories can carry out all of the tests, in particular, the strength of materials tests.
For some laboratories, this has required investment in new equipment and of course, different laboratories have different interpretations of how certain tests must be performed which makes choosing a test provider even more complex.
Test availability has reduced due to the increased testing time and manufacturers needing to get their assemblies tested within a short period of time.