Sunday, December 25, 2016

Joining The 21st Century, The Hard Way.

Warning: at some points this article may become excessively technical. Don’t worry, I haven’t a clue what I’m doing either, but it’s surprising how much we can learn given the right kind of need. I’d say don’t try this at home, but I just did and I’m still not dead. I guess it depends on how bonkers your domestic arrangements are.

We’ve survived the last few years on board with what I believe is termed a ‘rats nest’ of extension cables and whilst the 12 volt side of things has gradually come together to provide a reasonably coherent system that powers lighting, pumps and soundsystem power/phone charging via what we’ve always termed My-First-Inverter (a cheap device from maplin), the big power from our generator has always been assumed too dangerous and mysterious to play with so we’d run extensions along the deck every time we needed juice.

My old skipper Alan says POWER IS EVERYTHING, so with that in mind here is a little story of how far we’ve come.
Back at the beginning of this year and feeling unexpectedly flush I purchased a fancypants bit of technology, an inverter/charger that promised to deliver real, pure sine wave 220v AC power. the motivation was to power the computer on which I’m typing right now. The My-First-Inverter that we’ve had for years produces a simplified version of AC power, essentially just switching power back and forth 50 times a second (Hertz) and when we tried plugging the computer into it we noticed a disturbing and loud buzzing sound coming from inside; we decided that really didn’t sound too good so we switched it off. Ever since then the computer has only run when the generator was running, reducing its role more or less to writing invoices for work. This would not do forever.
I proudly screwed the new super inverter to the side of our battery compartment and cheerfully wired up the 12v side of things using the most monstrous cables I’ve ever seen, thicker than my thumb, but that was all I thought I could do. I had several longing examinations of consumer units (fuse boards for want of a better description) and was completely baffled so we decided we needed someone who knew what they were doing, an actual electrician. Our work promised a favour that at some point one would visit and help us wire everything up. 
Over the course of a few weekends Becky and I ran all the cables that would supply sockets around the home as well as the immersion heater and electric side of the oven. Under floors and through bulkheads, practising a kind of gonzo contortionism to thread the cables through. Going behind the port side water tank I couldn’t reach the cable end that Beck was waggling about for love nor money, so after a moment of head scratching I gaffer taped a spaghetti serving spoon to a stick for extending my reach and sort of snared the cable with it. Every electrician should have a spaghetti spoon in their toolbox, right?
Then we waited, but all the electricians at work were busy, running around daft busy. We were bumped to the bottom of the list.
One night in early summer the generator shut itself down unexpectedly, and I was horrified to discover an empty fuel tank, smoke pouring off the engine top and fuel dripping from all over the deckhead. I needed engineering advice, and after many questions directed at Damian, Wolfy and Robin I discovered the fuel lines leaked like sieves. No wonder the generator had been a bugger to start as at rest the lines were filling themselves up with air. The final straw that caused the rather dramatic leak was a large split that opened up in the line north of the fuel injector pump. I learned about bleeding air, non return fuel valves and the fact that I now required a third hand and a flip top neck to do up new hose clamps around the injectors themselves. I replaced the entire fuel line system from one end to the other and suddenly the generator would start straight away every time. Result.
I got all excitable about the possibility of making the generator ‘remote start’. Up until this point I’d have to go on deck, open a hatch, climb into the generator room and turn a key to make it go. We wanted to start the thing from the domestic side of our vessel. Robin drew me a circuit diagram and helped me learn all about the wonder of relay switches. These clever little devices enable a low power circuit, one that can work over a long run of cable, activate a high power circuit- like a starter motor. I did all the work myself, even sussing out a second relay was going to be needed for the engine preheat circuit and the sense of fist pumping triumph when I turned a key in our galley at the other end of the boat from the generator and heard an engine vrummm distantly to life was worth all the head frying lessons on it’s own.
We waited a lot longer for an electrician. They were busier than ever.
Just over a week ago the long wait was over, and Kevin arrived to wire up two consumer units, one direct from the generator, and one south of the inverter/charger. I sploshed back and forth through a wellington booted high tide to the merchants for missing parts and extra pieces, and I helped provide earth bonding for each unit by fixing a hefty copper cable to frames of the hull.
Our big moment arrived and we ran up the generator to test the circuits.
First inklings that things were not quite as they should be came with the socket tester telling us we had an earth continuity fault. ‘Never mind’ says Kevin ‘that might be ‘cos we’re on a boat, let us test the inverter’. I read the instructions one more time for luck and switched it on in the order I was told to. Second inkling of trouble came with the discovery that whilst it would happily invert power up from the batteries the promised automatic switch over to charging just would not happen.
So I rang Sterling Power, the device’s manufacturer. I was told in no uncertain terms that the generator was the likely culprit. What technical support actually said was ‘your waveform is crap phone up the manufacturer and get them to supply you with a better voltage regulator’. O-kayy then, but I bought the generator second hand five years ago. When I got off the phone Kevin hit me with the third and final inkling of bad shit. While I’d been trying to keep up with Sterling Power he’d been testing the supply, ‘The power looks like its coming out backwards and theres a massive earth leak’ said Kevin, ‘did I wire that control box up the right way?’ he said ‘oh, yes, I did.’ he said. He explained that generators were outside his field of experience, so I thanked him profusely for his work and helped him load his van. I was on my own.
Except, I wasn’t. There were knowledgeable people I could telephone and bug for advice, again.
So it’s more learning time, again. With masses of help from Robin, Barry at Maple Electrics, Kevin, Alan at BP Norse Marine, and Meccalte UK technical support, and slightly less help from the internet which is confusing as hell; I have embarked on my journey to understand AC power. Think of it as a sort of crash course in AC electrics and electromechanical engineering. I only tried this because well, you try finding a generator expert the week before sodding christmas.
The journey began with the how to of multimeters, and getting my head round the idea that why on earth is power coming mostly from the neutral wire.
I took the cover off the alternator, and gazed at the mass of dirty copper. Right. More tests. That one is live, so is that one a bit, but not the other one. And I don't know what this one does. The simplest answer is that whoever sold me the generator in the first place had wired it up the wrong way round. Ok, swap that wire for this wire. Next, earth leak. Could it be dirt and filth? I cleaned the rotor and stator up as best I could with Jizer. Oooh look at all those lovely diodes. I considered complete dismantling of alternator, baulked. Put it back together. Two hours later, same ‘earth leak’ but the other way around. Next the discovery that while the frequency was about right the voltage was under 200v. So I made another couple of phone calls and after assuring the manufacturers that whilst I was no electrician I was prepared to give any advice sensible consideration a method of increasing voltage while leaving frequency in the same place was revealed. The alternators output is transformer controlled. The transformer is that row of three copper sausages on top of the output stator. Its core is made of two iron forms, one is E shaped, and next to it is one that is I shaped. There is a TINY air gap between the two. Undoing all the nuts and carefully increasing that gap should increase the voltage. I do not know why. But I took the thing apart, cleaning as I went and after a few hours managed to wedge that gap open a bit. Reassemble again. Ran the bugger up and a moment of pure celebration when tests revealed 236VAC at 50Hz bang on. Put the generator under heavy load and that figure drops to 220VAC at 50Hz. Acceptable according to advice and it looks like I’ve successfully sorted two big issues. 
I’m still a way to go. The ‘earth leak’ may not be an earth leak at all. many older generators are non polarity specific, I’m told this means that voltage is measured across live to neutral, therefore output is the total of voltage measured live to earth (vessel) and neutral to earth. Somebody mentioned earth bonding neutral to earth as a possibility. I gave this a go and decided it was a bad idea when I got a bit of a zap, the sort that makes your teeth rattle, the generator made a terrible clunking sound while I convulsed so I guess that’s not a sensible solution, and understandably I’m reluctant to repeat the experiment live to earth.
So, all reassembled and running various things are working. One thing is not. Good news items are: No more extension leads, anywhere. This here computer runs fine on the new inverter, with no scary wasps nest within sounds. The immersion heater heats a tank of water quicker than it did. And the electric side of the range works for the first time ever.
Bad news item is: The sodding inverter STILL won’t flip over to charging. The received wisdom is that this is a sensitive piece of electronics and it is therefore extremely picky about the kind of power input it likes. Bollocks. One thing I somewhat unsurprisingly don’t own is an oscilloscope, a device that would help me to see the waveform depicted graphically. I am however not quite done yet, and apparently an old style 50 watt light bulb may help stabilise the waveform although I’m buggered if I know why. Another possibility is purchasing a thing called a voltage regulator, which purportedly may help to scrub the waveform up. This will need to be wired in just north of the offending inverter.
Of course, complete dismantling and cleaning of the alternator is still a reluctant possibility too, but since it appears to at least mostly work this will be reserved for last ditch engineering attempts.
Are any readers still with me? If you’ve made this far A) well done, and B) there is a distinct likelihood that you have become confused. Congratulations and welcome to the club because I am too. But I shan’t be beaten mostly because I’m definitely still not dead and I regard this as a bonus of sorts.
After coming so far the internet bit was easy. I just phoned up the mobile phone company and bought one of these fancy mobile wifi thingies. At least this appears to work without taking it to bits over and over again.

In an effort to celebrate things mostly functioning, last night we slammed some food in the oven and curled up to watch the silliest DVD we could find on the computer. It was brilliant.

1 Comments:

Anonymous Anonymous said...

Another post of creative genius. You'd never have these things to play with if you lived in a conventional house....and that wouldn't be nearly as much fun.
Can you weld off the generator?

Chris, Sydney, Au

8:11 pm  

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