>----------
>From: Rains,Mike[SMTP:[email protected]]
>Sent: Wednesday, February 05, 1997 1:22PM
>To: [email protected]
>Cc: '[email protected]'
>Subject: RE: Transformer Approvals
>
>John,
>
>My understanding of IEC1010 is that IEC742 only applies to transformers
>that are stand-alone (not built in). Transformers that are built-in need
>only comply with the requirements in IEC1010. While there is no specific
>section for transformers in IEC1010, there is a section for doing short
>circuit tests on secondary windings (4.4.2.6). The transformers would
>also have to meet the applicable spacing requirements in Annex D and the
>dielectric strength requirements in 6.8 and other construction
>requirements as they apply (e.g., double insulation, etc.). Regarding
>IEC950, I can't think of an instance where a transformer that met IEC950
>requirements would not also meet or exceed the IEC1010 requirements.
>There may be some conditions where it wouldn't, but I haven't run into
>one yet. I would challenge the interpretation that you received.
>
>Regards,
>Mike Rains
>Foxboro Co.
>>----------
>>From: [email protected][SMTP:[email protected]]
>>Sent: Wednesday, February 05, 1997 7:58AM
>>To: [email protected]
>>Cc: [email protected]
>>Subject: Re: Transformer Approvals
>>
>>Just wanted to thank you for your explanation. In this case, the
>>transformers are built in to the instrument, behind a panel that
>>requires a 'tool' (key locked) to gain entry. I did have some
>>confusion about this, because as you indicated, IEC 1010 doesn't
>>specify a specific transformer standard to follow.
>>
>>I guess that we now have (2) choices -
>>
>>1. Purchase and install transformers that have IEC 742 certification.
>> - or -
>>2. Purchase copies of both IEC 742 and IEC 950 and evaluate
>>whether the IEC 950 certified transformers meet the requirements
>>of IEC 742 for our equipment. This *may* involve additional testing
>>and would most certainly be more time consuming. Potentially it could
>>be less costly in the long run, as domestic manufacturers of general
>>purpose transformers seem to only be offering products with IEC 950
>>compliance. To get a transformer with IEC 742 compliance, I'd have
>>to switch from using Signal Transformer to Legrand or some other
>>European company.
>>
>>-----------------------------------------
>>John Bielot
>>Canberra Industries
>>Applied Systems Division
>>e-mail: [email protected]
>>-----------------------------------------
>>>
>>>On 04-Feb-97 you wrote
>>>
>>>
>>>Hello from San Diego:
>>>
>>>
>>>IEC 742 (aka EN 60742) applies to transformers in general and
>>>stand-alone transformers in particular.
>>>
>>>IEC 742 contains some additional requirements for stand-alone
>>>transformers compared to those in IEC 950 (aka EN 60950).
>>>
>>>Unfortunately, IEC 1010 (aka EN 61010) does not contain specific
>>>transformer requirements, so IEC 742 can be invoked if the test
>>>house so chooses.
>>>
>>>If your transformer is built-in, then I believe a transformer
>>>complying with IEC 950 also complies with IEC 742.
>>>
>>>It may be that the test house is simply saying that an IEC 950
>>>certified transformer, by definition (not by test), does not
>>>comply with IEC 742. In other words, they cannot accept, carte
>>>blanche, the IEC 950 certification as being applicable to
>>>IEC 1010, whereas they could accept IEC 742 certification.
>>>
>>>This may mean that the test house will need to conduct tests to
>>>demonstrate compliance with IEC 1010.
>>>
>>>
>>>Best regards,
>>>Rich
>>>
>>>
>>>
>>>-------------------------------------------------------------
>> >Richard Nute Quality Department
>> >Hewlett-Packard Company Product Regulations Group
>> >San Diego Division (SDD) Tel : 619 655 3329
>> >16399 West Bernardo Drive FAX : 619 655 4979
>> >San Diego, California 92127 e-mail: [email protected]
>>>-------------------------------------------------------------
>>
>>
>
