Re: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Pete Perkins
The US product certification system seems confusing to those who have not grown up with it and used it. It is divided, as has been discussed, between commercial/industrial (OHSA regulated) and retail/consumer (local AHJ controlled). OSHA has pretty clear requirements but enforcement is prima

Re: [PSES] Mandatory certification

2020-02-19 Thread Richard Nute
Hi Dürrer: 1. Self-declaration is not accepted by any jurisdiction (or by OSHA) in the USA. However, safety certification is not mandatory (or enforced) in some local jurisdictions. 2. Where the NEC is adopted by the local jurisdiction, the adoption may have exceptions and addi

Re: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Chuck August-McDowell
I think an example of the field inspection/label program not part of OSHA's NRTL program would be the City of Los Angles Department of Building and Safety. http://www.ladbs.org/services/core-services/plan-check-permit/product-approval/electrical-test-lab Note, I did not confirm they are not also

Re: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Regan Arndt
Hello Dave/Bernd. Just a comment/clarification. The field inspection/label program is not part of OSHA's NRTL program despite some NRTL's that conducted this service. I know it can seem confusing but there are also some non-NRTL's that conduct these field evaluations, all of which are under state

Re: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Ted Eckert
Hello Bernd, The requirement from the National Electrical Code is either an NRTL Listing or approval by the local Authority Having Jurisdiction (AHJ). The latter option means that a local electrical inspector or building inspector will look at the equipment to determine whether they think it is

Re: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Nyffenegger, Dave
Bernd, I don’t know any jurisdiction that would accept a manufacturer self-declaration if the jurisdiction is requiring a safety certification. An alternative to an NRTL listing is an NRTL field inspection/label which is unique to each product at each installation. -Dave From: Dürrer Bernd

[PSES] AW: [PSES] [EXTERNAL] Re: [PSES] Mandatory certification

2020-02-19 Thread Dürrer Bernd
Hello Ted, hello Regan, Thank you for your clear statements on NRTL certification. Can you please provide some guidance on the interpretation of the National Electrical Code NFPA 70 (2020 edition), article 110.3, on the suitability of installation and use in conformity with the NEC? Information

Re: [PSES] Keeping cellphone noise out of audio op-amps

2020-02-19 Thread John Woodgate
Thank you very much. Best wishes John Woodgate OOO-Own Opinions Only www.woodjohn.uk Rayleigh, Essex UK On 2020-02-19 12:20, Gert Gremmen wrote: Basically any connection to an opamp can create unwanted susceptibility. So a small cap to ground preceded by a suitable impedance for the frequenc

Re: [PSES] Keeping cellphone noise out of audio op-amps

2020-02-19 Thread Gert Gremmen
Basically any connection to an opamp can create unwanted susceptibility. So a small cap to ground preceded by a suitable impedance for the frequencies to be suppressed will do the job. What pins ? Those that have a substantial length (compared to wavelength) on PCB (or off PCB). By placin

[PSES] Keeping cellphone noise out of audio op-amps

2020-02-19 Thread John Woodgate
I see two apparent ways of keeping cellphone noise out of audio op-amps: - 10 pF between + and - inputs; - 47 pF (or similar) from output to inverting input. Which is usually more effective? I suspect that the first one is, but I see it less often. -- Best wishes John Woodgate OOO-Own Opinio

Re: [PSES] SV: [PSES] Ground copper fill on signal layer on multilayer PCB

2020-02-19 Thread James Pawson (U3C)
Hi Amund, If you have the space on the board then a ground fill around the perimeter (on all layers) probably won’t do any harm. Whatever ground fill strategy you decide on for the signal layer I would make sure it is well connected with vias to both of the adjacent planes along the edge nea