Golly gosh, been a little hectic here this last few days to say the least. I’ve got lots on the ‘to do list’ as it is but we’ve had a couple of unexpected disasters here that have shaved a few days off the holiday, and jobs off my list. Number 1 and 2 being generator related, not just Harry my HR2 Lister but Cyril the SR2 next door too. Lost track of the days right enough but one fine frosty morning I got up to do the usual chores first thing, one of these being a look into the ‘power station’ to see what we’ve generated or used overnight.
As soon as I approached the shed door I was greeted by the very expensive smell of the ‘magic smoke’ from inside the shed It was warm too indicating that Harry had been running over night. This would be on account of me altering the inverter settings to set the inverter to start the generator at 60% SOC and stop it at 80% SOC, that’ll be ‘state of charge’ of the batteries. I had gradually been increasing the lower setting from the default 40% and reducing the upper setting from 100%. My logic being that the batteries last longer if cycled less and the extra solar from the lengthening days means the batteries are charging faster during the day.
Using the generator to charge the batteries fully is very wasteful due to the way lead acid batteries (most batteries in fact) like to be charged. The initial charge, called the ‘Bulk’ phase is done at a high current and so the generator is well loaded and running efficiently. However the next phase, ‘Absorption’ is done at much lower current and can take up to three hours to fully charge a battery. So, with longer days and still plenty of wind and hydro it makes more sense to let nature do this bit. Anyway, I guess I’d set the lower threshold a little high so, around 4:00am the generator must have started to charge the batteries.
Unfortunately something went wrong Trouble is, I’m not entirely sure what!!! Luckily when I bought this massive Lister HR2 15kVA set with a mere 50hours on the clock some 13 years ago it came with a load of spares. I paid £1000 for it delivered to Sconser and being a ‘standby set’ from a satellite tracking station it had hardly been used but was well serviced. It even had a heater in the sump, so was kept warm for twenty odd years before I bought it. Amongst the injector pipes, filters, springs and gaskets was a brand new, yes brand new starter motor.
Fitting the starter is a pretty straight forward job, though mine has extra relays and wiring for the ‘Murphy ASM 170’ start module. That will be the same one I’m fitting to Cyril next door https://lifeattheendoftheroad.wordpress.com/2016/03/08/the-murphy-asm170/ and, as I hinted that’s not going too well either. The generator is starting and stopping better than it’s ever done at ‘Number 3’ but it’s started tripping the RCD in the house More of Cyril later, back to Harry, well, I’m a little perplexed cos I’ve not actually identified the cause of the problem yet. Did the starter stick in and get driven by the engine? Did it short out internally or did the inverter send some wrong info to the start module.
Truth is I’ve not got a clue and even downloading the ‘event history’ from the inverters SD card hasn’t really helped. The data shows a low SOC start request being initiated around (3:53 actually an hour later) EDIT, further investigation reveals that it was a ‘BMS’ request
Roughly translated this means the genny ran from 3:53 to 6:03 when it was shut down due to ‘reverse power protection’. Usually this means that the AC grid is receiving more renewable energy than the energy generated by the generator. In effect this means that say the wind has got up or the sun come out (though not the latter at 7:00AM) At 6:24 another start is initiated and this continues for another hour and a half (another 4 starts) until 8:25 when the generator fails to start and I guess the starter motor starts belching the ‘magic smoke’ So, until I get to the bottom of it I’ve switched the generator to ‘manual start only’ and increased the minimum time between starts to 60 minutes.
Well then, methinks I’ve gotten somewhere after studying the ‘event history’ and ‘logging’.
I know it’s all gibberish, it was to me for hours but it would appear that the generator was requested at 70% SOC under a condition known as a ‘BMS full charge request’ which overrides the SOC request. Needless to say I’ve turned that function off now. It doesn’t explain what wrecked the starter but it does explain why the generator was running so long and kept going into ‘reverse power protection’. These SMA ‘off grid’ inverters do seem to have their own way of doing things!!! I do like this German stuff, you can feel the quality in it, a huge die cast aluminium chassis to take the heat away and lovely soldering on all the boards. However the Sunny Island SI 6.OH does seem to have a mind of its own!
Desperately boring stuff I know so I’ll try and get ‘back on track’.
OK, I’ll try again, I’ve been writing this for three days now and still no nearer posting it! Can’t even remember what I’ve been doing as I’ve not even filled in the ‘paper diary’ this week.
Thursday I’ll not forget right enough as we went to Aultbea to visit my dad at the ‘Isle View’ http://www.isleview.co.uk/ care home.
The isle in question being the Isle of Ewe situated within the large sea loch that was once a marshalling point for the Russian convoys and a well used anchorage for the Royal Navy.
I spent a bit of time diving in the area in the seventies and eighties, returning over twenty years later with my son and his pals for a ‘look see’ https://lifeattheendoftheroad.wordpress.com/2009/09/21/batteried/
Funny how things turn out, if anyone had said to me in 1980 that my father would end up in a care home there I’d have said they were mad! Still, he couldn’t be in a better place, the staff are excellent and the food great. I know cos we always turn up for lunch Not deliberately of course, it’s just that if we catch the 7:55 ferry and drive straight there we arrive just before meal time. This lasts about an hour and a half because the staff take so much time and care over all the guests. There’s no hurry or rushing about, everyone gets a friendly word and some good craic with their food.
Even managed to get a raspberry and smile out of me dad, who is settling in there very nicely.
In another bit of synchronicity someone I met via the Internet and blog lives on the island and has family in the same home. So after lunch I left me mammy with pop and went to meet up in the hotel http://www.aultbeahotel.co.uk/ Methinks I will have to return for longer, my friend also lives ‘off grid’ and has his fingers in some very interesting pies.
The piggies return
Leaving the home around 14:30 we headed the 80 miles to Kyle
to collect two pigs in nine boxes from Lochalsh Butchers. One compensation of the 100 mile drive from Sconser to Aultbea is the stunning scenery along the way.
The pigs weighed 66kg and 83kg so, with half a pig going to a friend that meant we’d around 100kg of pork to deal with and it was after 19:00 when I got in By 22:00 we’d had enough so left the rest in the car, which was just fine, it was a frosty night and the freezer could only freeze so much anyway.
Believe me, this is only a fraction of it, it took us three days to get it all in the freezer as we can only freeze 28kg per 24h. I dunno how many sausages we had but it was a lot!
Not sure what happened on Friday after another few hours of bagging sausages, probably I was round at the neighbours working on their generator or servicing the pig trailer. I did that at some point recently in preparation for its trip south to collect a wind turbine. Just changed the number plate and removed the wheels and bearings to check and grease them.
I did make dinner for my son and I right enough, it was a small haggis and black pudding from Cockburn’s of Dingwall http://www.cockburns-haggis.co.uk/Haggis
I boiled the black pudding in tinfoil for forty minutes along with the haggis rather than frying it in slices, boodly delicious with some mash and mixed veg.
A touch of paranoia
Friday night saw a good breeze of wind and after a couple of glasses of red I went out to the ‘power station’ to check on the wind turbine output. Fatal mistake as I managed to convince myself that there was something wrong with it. The voltage and current values did not seem to be stable or correspond to the amount of power generated. After braking the turbine and metering across the phases I further managed to convince myself that there was some serious issue within the turbine head, faulty core, poor connections or duff slip rings. Another glass of wine helped confirm this and before i went to bed I’d convinced myself that I needed to lower the turbine to check it.
True to form, I was up early on Saturday to lower the turbine.
The 11m mast makes this a wee bit more of a chore than the 7 m mast at ‘Number 3’, for a start the ‘gin pole’ is much heavier. This makes it a good deal harder to set up than on the shorter mast, it also means that you really need a jack to start it off. With the shorter mast you could easily just lift the mast by hand enough to start it tipping. Obviously this would be AFTER you’ve connected the Tirfor wire.
Left hand picture is the old method complete with Skye Batik http://www.skyebatiks.com/ shorts and the right hand picture is hydraulic jack method required for the 11m mast.
In the pishing rain and with half a gale blowing I managed to lower the turbine and remove half of the top cover for inspection.
Everything was in order and all resistances similar across all the phases, both before and after the slip rings!!!! Having said that I had taken the original readings on my very expensive Fluke ‘auto ranging’ multimeter and I think I got a little confused. A cheap Chinese jobbie set at 0 – 200 Ohms seemed to indicate that all was well all the way back to the inverter. So, basically I’d spent most of the day working my socks off and achieved nothing other than ‘peace of mind’.
Still, it was good exercise and lessons were learned
The day after the sun was out, everything seemed rosy and I got a tow bar fitted to the ‘Egg Chariot’, that’ll be wifey’s Subaru Forester. A task that proved incredibly easy, I had the choice of a UK made one for £200 plus an ‘arm and a leg’ for delivery or one from Poland for £62 plus £20 delivery!!! How is it possible to send something from Guetersloh in Germany to Sconser than from Wolverhampton to Sconser? Sure, I had my doubts about the quality but this tow bar wasn’t really going to get much use so I wasn’t too fussed. However, it was well made, thickly ‘powder coated’, easy to fit and came with all the hardware required for installation. The instructions were carp right enough, as were the imitation ‘Scotchlok’ connectors but everything else was first class http://www.ebay.co.uk/itm/151751017732?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Another job done on the turbine was the addition of extra mounting studs grouted into rock with Hilti HIT RE 500 resin. The original Proven/Kingspan mount had 6 x 24mm studs, which is probably just fine but after ‘storm Henry’ I decided to add more for ‘peace of mind’. I had plenty of M20 A4 stainless studs and had seen some resin very cheap on eBlag.
So, with a 24mm bit I bored 5 extra 400mm holes into the rock and fitted the extra studs. Once the holes were drilled then I power washed all of them and hoovered out the water, the resin is then injected into the hole and then the stud inserted. The resin takes about 9 hours to cure at these temperatures so I’ve not actually torqued them up yet.
And I have no idea how I ended up with one dirty foot!!!!