Monday, 27 May 2013

Advanced Alternator Regulator

To finish the alternator modification I have added to the house battery system an advanced alternator regulator made by Sterling Power Products  I chose the ProD model.

Unit on the right.  The left is the MPPT

The first thing to do was to connect 2 wires to the inside of the alternator.  Only one of these wires is used but it need to be determined which.

These wires go to the brushes in the alternator.

Cap back on and wires out of a convenient hole.

With the alternator running normally its necessary to identify which type of alternator sensing you have.  Mine is a Negative sensing.
Once the right wire is found simply snip the unused one off.

This explains what they do but in a nutshell it changes the charge profile of the original regulator in the alternator without modifying it. It will fail safe to the alternators own regulator if it encounters any number of possible problems protecting the alternator and batteries from themselves as it makes the alternator & batteries and connecting cables work much harder for longer.  The full manual is here.

The additional load on the alternator started to cause the belt to slip on engine start up as the ProD loaded the alternator.  I could have added more tension to the belt but this just adds extra loading the the engine front bearing and the alternator bearing. To overcome this I applied some Belt Dressing which has done the trick.

While out this week the engine clocked up 200 hours.

It's very noticeable how much quieter the engine is becoming as time goes on, and since the alternator modification how much smoother it feels.  I can offer no explanation for this tough.

I have decided to change the central heating boiler and have ordered a Hurricane CH25

The Mikuni MX60 has been and continues to be great, its done sterling service for 2 winters but I want the greater flexibility the Hurricane offers with its zoning, hot water only and the added feature of being able, with the use of an additional heat exchanger, use the the engines waste heat to heat the radiators.

More on this soon.

Another modification on the horizon:-   I have ordered a new propeller.  The current one is 21 x 16 and I shall be replacing it with a 21 x 21.  I should get this in a few weeks and have a slot booked on a local crane day but I might try to do it in the water.  I looking into the feasibility of this.


Thursday, 16 May 2013

Down The Tubes

I've decided to totally replace the flexible rubber sanitary hose because of the smell it was leaching.  I was going to just replace the long run in the saloon and kitchen but decided in for a penny etc.

Initially I thought this would be a complete nightmare, but a bit of thinking about it and a plan came together.  

The worst part was drilling a new 2" hole in the rear bulkhead.  This of course was in a very awkward position and took about an hour as I had to keep resting because of the horrible position I had to get in made me all hurty.  I lost a bit of knuckle skin in the process of course.  I wasn't able to use the original hole as I wanted to maintain the current system until I was ready to chop it out as I had no idea how it would go and I wouldn't be able to re-fit the flexible one.

A week or 2 ago I removed a bathroom cabinet and a section of wall to gain access to part of the system. Link here.

One of the main problems was going to be turning the corner to the right about 4" above where the vertical tube disappears.  I was going to simply draw the tube back and wrap it in aluminum tape to add another barrier which was suggested on the canal forum, then connect either side, Instead as I drew it back and forth I realised I could get a new piece of plastic sanitary hose round the bend.  I already had a piece of this in the system near the toilet and this hadn't developed any smell.  Indeed even when this 9" bit was removed after the previous tube purging of a dozen or so fresh water only flushes there was no smell even from the inside of the tube.

I also had to cut a 6" hole in the electric cabinet in kitchen to get my hand in to guide the the new plastic tube through the bulkhead and it's onward journey.  In doing so I shorted the Cat5 cable to the inverter against a mains wire and have damaged my inverter network bus, PC/USB interface unit and the remote panel, 1 Cat5 cable and 3 mains cables.  The cables were easily repaired as all of them were only slightly nicked, but just enough to short across the cutter :-(

Similar to this 

The new pipe was easily installed from the toilet all the way to the tank.  The whole system was replace in about 4 hours. I'ts also now easy to inspect, remove and service and only has about 2' of flexible plastic pipe throughout.

This is the only photo I took

I withdrew the old "No Smell" tube which stunk and put it outside.  To my surprise there was a lot of fine bits of lime scale grit about the size of large tea leaves inside the tube which were brown like teas leaves when wet but curiously almost white when dry.  These didn't smell at all when dry.

Next morning I noticed the smell in the saloon had completely gone and the back canopy area was where the pipe passes under the floor was also smell free.  Long may it remain.

Total cost of the replacement tube and fittings cost about £70, damage to the inverter and accessories?  I'll let you know.  

Saturday, 11 May 2013

Alternator Modification

I've been having trouble getting my house batteries topped up and getting enough amperage from the engine alternators even though they are now paralleled.  Also we have an electric combi oven on board and the original idea was that the oven would run through the inverter powered entirely from the amperage supplied by the 12v alternators.

For some reason despite my best calculations this simply didn't pan out the way I anticipated, so the option was to replace the house alternator with one of a larger capacity.

A bit of digging around on good old ebay and I managed to find a 215amp alternator which is 100amps more than the one originally supplied as the house alternator.  It was also fortunate that the mounting spigot was the same 55mm as the original.  I’m thinking this might be some sort of standard.

This is what the alternator setup looked like originally.

The new larger alternator obviously requires a much larger belt to drive it due to the extra load, so I ordered it with a PK7 pulley. That was the easy part!

This extra load could not be delivered by the original single V belt and the ratio was not sufficient spin it at optimum speed in the cruise RPM range. 

I then needed to get the larger drive pulley. Originally I thought this would be a simple job of just getting one off the shelf as you can with many other types of drive pulley. However the PK standard of pulley seems to be specifically used in an automotive situation and the engine manufacturers make their own pulleys to suit.

This left me with no choice but to get one made. Once again Canal World Forum held the answer as one of the members Tim Leach of Dutton Dry Dock offered to make me one for me.

I was able to get RPM and charge data for the alternator and the max over speed rating from the supplier so I was able to work out the drive ratio. I settled on 4.5:1 as this would provide a very high charge at tick over and maximum charge at cruise revs of 1300rpm but would not over speed it at maximum RPM which in reality is never used. Knowing the small pulley diameter I worked out the large one needed to be 235mm

The first job was to get the existing pulley re-machined to take a 50mm shaft.  

This part was done by a local engineering firm as it needed welding which I did. The shaft was left long to allow for design as it had to be made up in situe. Once the design for the pulley was finalised all the parts were sent of to Tim.
As the actual belt alignment could not be predetermined exactly the best solution was to use a Taper Lock pulley and hub. This design permits the pulley assembly to be mounted anywhere on the shaft then locked off.

Old system alignment

A week or so later the pulley assembly was returned to me along with a couple of spacers I also needed. I somehow managed to lose the key which I suspect has fallen overboard so I scavenged for a but of scrap and armed with nothing more than an angle grinder and file I soon made another.

 This bit of scrap turned into the new key

All the modifications done

One thing I didn't allow for was the bolt heads sticking out from the hub face and the original ones that would have stuck out from the rear of the pulley and sitting on top of the shaft fixing bolts, so I had to use countersunk bolts instead necessitating the back of the pulley to have holes counter sunk.  

Thanks once again to Garth at The Boat Yard Ely for the use of his countersink and pillar drill.

This is what all the new parts look like.

I then bolted the new shaft into place.

Then I positioned the new pulley and hub assembly on the shaft. Only 9 x M10 bolts!

Having previously fitted and connecting the new alternator I fitted the belt, set the alignment then locked the new pulley to the shaft.

Job done!

So what has all this achieved?  Well I now have over 300amps of charge with the 2 alternators working in parallel.  This means I will be able to charge my batteries much quicker and more deeply.  There's a bit more this this as any battery expert will tell you. 

Also my electric oven draws roughly 220amps from the batteries via the inverter.  The basic maths on this is inverted power is 10v divided by the mains wattage. So 2200watts = 220amps at 12v out of the batteries.  10v is used to account for conversion losses.  It's not exact but it is pretty close and simple to do in your head. The previous setup wasn't quite able to supply this.  This means I can run my oven with the engine only and there's a hidden bonus in that any extra power from the alternators will go into the battery charging system so on initial tests I was running the oven and still getting a surplus 56amps of charge.  If the batteries are were even flatter there would be a theoretical 95amp spare available.

Conclusion is this has been a worthwhile modification. The next stage if necessary will be to add an external alternator regulator to increase the regulated charge voltage to 14.8v from the normal 14.4v  This is a better charge profile for my battery type.

One final note.  I did a rpm check with the engine running at a shaft speed of 1035rpm the alternator was spinning at 4565rpm so the ration calculations were pretty spot on.

Thursday, 2 May 2013

A Boaters Favorite Subject

Yeh toilets again!

Following the removal of the 230v toilet in favor of the 12v again I was left with a gap behind the toilet as I had to remove some extra wall to get the plumbing connected to the 230v one.

I made a template a week or so ago and my brothers stone firm cut and polished a cover plate out of a type of man made porcelain.

So why are there tiles missing on the lower left?  Well, first of all it was an accident of removing the skirting board but then it became apparent this was a fortunate accident as I have another problem that needs fixing and these broken tiles sowed a seed to part of the solution.

The rubber sanitary hose used to take the macerated waste to the holding tank which is sold a "Smell Free" is now after only a year leaching a nasty smell in the boat and needs replacing.  This was supplied by a an expert firm in the field.  When questioned about this I was told that basically all flexible sanitary hose will leach smell sooner or later.  This I find unacceptable and have taken it up with the supplier.  In all fairness to the supplier I don't think they are to blame as they only brand that which is available elsewhere.  Neither the less to be told this hose should be regarded as an item that will need replacing anywhere from a year onwards is just not on.  Plumbing as far as I am concerned is a fix and forget item!

So in order to get the old hose out and new one in access has to be got.  By removing the right hand bathroom cabinet:-

I was able to carefully remove 2 tiles to replace the damaged ones:-

Then using a borrowed Fein Cutter (Thanks Garth at The Boat Yard Ely) I gently cut through the board behind ensuring not to plunge any deeper needed to breakthrough because behind are plenty of services:-

As you can see!  I'm pleased to report nothing unintended was cut or even nicked.

So if anyone want's to buy me a pressie, a Feins Cutter will do.  In case you're not sure this is what one looks like.