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    Lightning protection in Africa

    The $64,000 question for us is it worth spending money on air terminals at all? Our buildings are mostly corrugated “iron” roofed and of low value. If lightning blows a hole in the thin roof it’s cheap to repair. What we don’t want though is the occupants to be hurt or the electronics to be...
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    Lightning protection in Africa

    Thank you for your support. I am very interested in your costing, if only because I may need to get a church's earthing in UK fixed as it is fractionally over the 10 ohm limit. In Zambia we have been quoted only £2200 for the four 15m poles, spikes/air terminals, 4 earth pits and wiring. That...
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    Lightning protection in Africa

    I have had a think about all this and come up with the attached which is my attempt to arrive at a lighting protection concept that is achievable in Africa considering the limited budgets usually available there. It includes some photos of "good" practice from Austria where I was last week...
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    Lightning protection in Africa

    Following a quick read of http://www-public.tnb.com/eel/docs/furse/BS_EN_IEC_62305_standard_series.pdf I understand more. Interesting that they are talking of 10 ohm earth resistance as that means the earth is going to jump many 1000s of volts if no SPDs One thing I don’t understand is the...
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    Lightning protection in Africa

    Thank you. I put the things I especially wanted to know in bold above to make it clearer. Don't know much about BSEN 62305 and my electrician son does not either because lightning is not a serious problem in UK (and we don't use TT earthing much), but in Zambia it would be classed at very high...
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    Lightning protection in Africa

    Just measured an old church in UK which has 2 solid 50mm2 round bars, presumably of copper, down from its lightning conductor. They go into the ground in 2 places 4 m apart either side of the Norman tower. No idea what is underground there but it passed its last test for earth resistance 5 years...
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    TT supply with TNS sub mains

    Bizarre things happen in Africa. In South Sudan where I have worked the DNO has a good quality new TT system. Yet the DNO often comes along and cuts your wire to your earth rod leaving you no earthing at all. No explanation for this practice is given. I had one site where the live was...
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    Lightning protection in Africa

    I have a problem with lighting protection in a charity in Zambia. The earthing is TT, i.e. earth pits or rods are provided for almost every building. I have measured the resistance of these and some are half to one ohm. But others are 100 ohm which is is dreadful and we are redigging these...
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    Solar Panel immersion heater automatic switch.

    If the mains is disconnected from the inverter it will drop out as the inverter can't deliver current without a mains connection, as otherwise it does not know how to synch with the mains frequency. How exactly are you deciding when to switch in the next capacitor? When you measure the grid...
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    What have you been up to lately?

    Have been busy developing the Wi-Fi version of the Intelligent Immersion solar diverter, which we are calling the I3. This performs all the functions of an I2 solar diverter but adds a wireless interface so owners can monitor and plot graphs of several energy flows from a smartphone, tablet or...
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    PV immersion heater proportional control

    The new relay equipped version of the Intelligent Immersion provides this function. It measures the export, ignoring the variable immersion load, and switches on its relay at the value you set. Useful for say a heat pump where the user wants it to turn on at 2kW export yet, if the export is...
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    PV immersion heater proportional control

    Not actually true as the EMMA is EMC compliant too and so is the Intelligent Immersion I2. And the latter is based just round the corner from you!
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    Another immersion heater controller....

    I agree. Some things we have found looking at some diverters are:- Not using any form of EMC filtering beyond maybe one capacitor and a VDR, which are totally inadequate to meet the regulations Not using proper fusing so a shorted load will destroy the unit Use of burst firing which often...
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    remote switch for immersion heater

    Not exactly sure what you are trying to do here but solar immersion diverters such as ours (Intelligent Immersion model I2) and Immersun's modulate the power into the immersion so you don’t need to have a switch to turn them fully on or off. We do though offer an option where the load is turned...
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    Proportional Controller Technologies

    The published links favour one particular product whilst casting doubt on all the others. E.g. it is trying to claim that all apart from PWM ones have no Lab Conformity Certification whereas theirs does. That might be true of some/many but what evidence have they used? For instance our own...
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    PV immersion heater proportional control

    My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient...
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    PV immersion heater proportional control

    A lot of the companies in this field are quite new and so there is indeed a risk that your support lifeline will fail if they do not last. The important thing therefore is to get a reliable product that will last you many years even if the company vanishes. E.g. does it have a fuse to protect...

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