[OpenTRV-dev] Radio Conundrum

[Joseph Heenan]

Hi Damon,

> On 9 Aug 2016, at 14:04, Damon Hart-Davis <dhd at exnet.com> wrote:
> 
>> If one could find something that is a finished product (for the sake of
>> argument, say, a CE marked USB dongle containing an RF module and an
>> antenna) and plug it into a TRV, then the RF aspect of demonstrating CE
>> compliance might be alleviated, but whatever it "plugs into" needs its'
>> own compliance if it is to be put on the market.
> 
> At the very least this allows me to ship our valve unit first without CE stamping for radio, ie decouples the (initial) CE marking for the valve in the first instance from the thorny radio issue.


One thing to be aware of is that when you CE test the valve, you normally test it in a "typical" configuration. If it is expected that 90% of the users will run the valve with a radio module, you may find you need to CE test with the radio module in place - if that is what happens, you're not really saving anything.

I am not an expert in CE, so I wouldn't recommend taking my advice - given you will definitely be doing some CE testing, I'd engage with one of the CE test houses to get advice. I have only had (mostly indirect) dealing with one; http://www.yorkemc.co.uk - their pre-sales engineers know what they are talking about.

Of course their advice will tend towards the options that require more time in their test facility / they will be cautious and tend to recommend towards more testing to ensure any liability isn't with them if anything goes wrong; pointed questions like "Do I really have to do <x>?" "How big is the risk if I don't do <y>?" can help.

At the end of the day in many cases CE is a self certification, there is no legally established minimum level of test and I believe you can count the number of times Trading Standards have insisted on a full recall for CE certification failures with just your fingers, and even then the cases I have heard of are at the level of power supplies that had a tendency for passing mains voltage AC across onto their outputs. It's all about risk management and mitigation.

(You may or may not find that any public / product liability insurance you have has criteria for test buried somewhere.)

Cheers,

Joseph