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Date: Fri, 24 Sep 2010 03:39:58 -0700 (PDT)
From: Tony Baldwin <tonybaldwin@yahoo.com>
To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: Photovoltaic Installation
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Hello Hugh.

I had a wander about with my transistor radio this morning with the inverter 
switched on.
I found that the noise generated covered the whole of the radio's coverage from 
150 KHz to 30 MHz with peaks and troughs. The worst affected was the whole of 
medium wave especially at the bottom end and 80m. The noise it makes is very 
similar to the video noise you get on 6m.
It is certainly carried on the wiring and it especially bad in the house on MF 
where I'm surrounded by mains wiring, but a good 50m from the inverter.
Outside I lost the noise at about 30 metres from the nearest mains wire on MF 
with the radio's ferrite rod antenna.
My inverter is a pure sine wave and not square wave and unfortunately (for you) 
it still creates noise even when it's on standby, so probably no respite even 
after dark on a photovoltaic system.

Your neighbour's system would be a grid tie inverter accurately synchronised to 
the incoming mains phase and frequency, so not too much fear of incorrect 
phasing and big bangs.

Sorry to be the bearer of bad news

73, Tony EI8JK




________________________________
From: Tony <ei8jk@o2.ie>
To: rsgb_lf_group@blacksheep.org
Sent: Fri, September 24, 2010 9:31:50 AM
Subject: Re: LF: Photovoltaic Installation

Hello Hugh.

I have a wind turbine and an inverter which is an ordinary computer UPS, and it 
does give blanket noise all across LF, MF & HF. It's only when you get to VHF 
that it can't be heard.
I have no idea how far it radiates but I will test it out for you later and see 
how far away I can get before I lose the noise.

I have the advantage of course that I can switch it all off when I play radio.

Tony, EI8JK.


On 24/09/2010 08:53, Hugh_m0wye wrote:
> Greetings to the LF group,
> My neighbour informs me that she is intending to have photovoltaic panels 
>installed on her roof, in a scheme where she gets free electricity (all 
>subsidised by the government of course!)
> 
> My concern is the possibility of high levels of interference generated by the 
>kW inverters needed to pump electricity back into the National Grid. I would 
>guess that such invertors probably operate kHz and might be expected to 
>interfere with LF and VLF reception. The wiring to all the panels on the roof 
>might act as a very good aerial!
> 
> It also occurs to me that any lack of RF immunity to my transmissions, in the 
>new installation, might have dramatic consequences - I know from studying 
>electrical engineering at college that connecting a generator to the grid with 
>incorrect phase leads to a big bang!
> 
> Has anyone any experience of such installations?
> Perhaps someone has one nearby and could comment on any EMC effects.
> 73
> Hugh
> 
> 
> 


      

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<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div>Hello Hugh.<br><br>I had a wander about with my transistor radio this morning with the inverter switched on.<br>I found that the noise generated covered the whole of the radio's coverage from 150 KHz to 30 MHz with peaks and troughs. The worst affected was the whole of medium wave especially at the bottom end and 80m. The noise it makes is very similar to the video noise you get on 6m.<br>It is certainly carried on the wiring and it especially bad in the house on MF where I'm surrounded by mains wiring, but a good 50m from the inverter.<br>Outside I lost the noise at about 30 metres from the nearest mains wire on MF with the radio's ferrite rod antenna.<br>My inverter is a pure sine wave and not square wave and unfortunately (for you) it still creates noise even when it's on standby, so
 probably no respite even after dark on a photovoltaic system.<br><br>Your neighbour's system would be a grid tie inverter accurately synchronised to the incoming mains phase and frequency, so not too much fear of incorrect phasing and big bangs.<br><br>Sorry to be the bearer of bad news<br><br>73, Tony EI8JK<br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><div style="font-family: arial,helvetica,sans-serif; font-size: 13px;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Tony &lt;ei8jk@o2.ie&gt;<br><b><span style="font-weight: bold;">To:</span></b> rsgb_lf_group@blacksheep.org<br><b><span style="font-weight: bold;">Sent:</span></b> Fri, September 24, 2010 9:31:50 AM<br><b><span style="font-weight: bold;">Subject:</span></b> Re: LF: Photovoltaic Installation<br></font><br>
 Hello Hugh.<br><br>I have a wind turbine and an inverter which is an ordinary computer UPS, and it does give blanket noise all across LF, MF &amp; HF. It's only when you get to VHF that it can't be heard.<br>I have no idea how far it radiates but I will test it out for you later and see how far away I can get before I lose the noise.<br><br>I have the advantage of course that I can switch it all off when I play radio.<br><br>Tony, EI8JK.<br><br><br>On 24/09/2010 08:53, Hugh_m0wye wrote:<br>&gt; Greetings to the LF group,<br>&gt; My neighbour informs me that she is intending to have photovoltaic panels installed on her roof, in a scheme where she gets free electricity (all subsidised by the government of course!)<br>&gt; <br>&gt; My concern is the possibility of high levels of interference generated by the kW inverters needed to pump electricity back into the National Grid. I would guess that such invertors probably operate kHz and might be expected to
 interfere with LF and VLF reception. The wiring to all the panels on the roof might act as a very good aerial!<br>&gt; <br>&gt; It also occurs to me that any lack of RF immunity to my transmissions, in the new installation, might have dramatic consequences - I know from studying electrical engineering at college that connecting a generator to the grid with incorrect phase leads to a big bang!<br>&gt; <br>&gt; Has anyone any experience of such installations?<br>&gt; Perhaps someone has one nearby and could comment on any EMC effects.<br>&gt; 73<br>&gt; Hugh<br>&gt; <br>&gt; <br>&gt; <br><br><br></div></div>
</div><br>

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