davidk65
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Posts posted by davidk65
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Try connecting a 240V incandescent filament lamp between Live and Earth, and report back whether the lamp lights or not.
cheers,
Pete.
Hi Pete.
Dealing with other comments on this thread: i.e.Use an Incandescent Lamp to test:
i) Inverter Output voltage: In this test, the lamp across L + N, the lamp reached it's full brilliance. I concluded that as stated by others my multimeter cannot read the voltage of the inverter and the output from the inverter is correct. Thank you for that.
ii) Lamp Test testing Line + Earth: Connected this way, the lamp did not light. Does this indicate that the earth and neutral of my inverter are not bonded to each other.
On the case of the inverter there is a double 13amp type socket outlet. The earth connection of the sockets are connected directly to the inverter case and the case is attached, via an earth cable, to the hull of the boat. From the checking I have managed to do today, the earth leads from the sockets that we use appear to be connected at a common earth junction which is connected to the hull. I have yet to find this connection as I have only determined this with the use of a meter on continuity.
iii) RCD/MCB: In close proximity to the inverter, but located in such a position that I can touch but I am unable to read the information on the unit, there is either an RCD or an MCB, but I cannot determine which. Please can you tell me what are the distinguishing features of either of these devices? What also puzzles me about this is; because I connected a lamp, Line to Earth, would this/should this have caused the RCD/MCB to trip?
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Try connecting a 240V incandescent filament lamp between Live and Earth, and report back whether the lamp lights or not.
cheers,
Pete.
Hi Pete.
I haven't tried the test you mention on the boat. I know that if I was to do that at home, if the earth was good, the light would come on at full brilliance, but I have measured the voltage (L to E) on the boat and that only reads 96 volts. In view of this I assume the lamp would be dim or not light at all.
From other comments on this thread, I have come to the conclusion that the neutral on my inverter is not connected to earth. The 230 volts the inverter is supposed to be capable of delivering appears at two points, Line and Neutral, both created by the components and inverter circuitry. The only valid earth connection being the inverter case which is not connected or needed in providing an ac output. If my assumptions are correct, testing the external wiring, Line to Earth, should be nil volts, so also would be Earth to Neutral at nil volts i.e. earth in this contexts being a "mechanical" connection to the hull and not an electrical connection to a Neutral center point internally on the inverter circuitry?
Question: Why is there a voltage showing on the Line to Earth on any of my ac sockets?
I now think it's time for me to go and lay down in a darkened room to rest my brain!!
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It would help to know what make and model the inverter is but...
The low voltage may be either a symptom of your meter measuring a non sine waveform or it could be that the voltage is reduced at low power outputs to save power when it is on standby, some do this. I guess that as long s it is running what you want it to run without problems there is no point in doing anything about it.
Regarding the assymetric voltges on live and neutral, It sounds as though your inverter is one where the neutral is not bonded to the protective earth.
On most units this can be achieved by simply wiring a link between the neutral and earth at the inverter but you will need to make sure that this is possible with your unit. You can do this by temporarily connecting an incadescent bulb between both live and neutral and protective earth, it should not light up and when connected the voltage between the other line and earth should be more or less the same as the live to neutral voltage.
Also it is essential to have RCD protection as close the the inverter as possible and a good bond to the hull of the boat (given it is a metal hull of course).
Don't worry about the lack of a ring main, as long as your boat is wired with 2.5mm blue artic (as most are), it will carry even the full output of the inverter with negligible volt drop.
Regards
Arnot
Regarding the internal connections of the inverter, I have contacted the supplier and asked for more details. Good point about the earth connection mentioned in the inverter literature, it will be for the case to be earthed and not a Neutral point to earth. The voltage readings obtained I think indicate this (L-N = 173 v. L-E = 96 v. E - N = 76 v) if I add together the 2 readings 76v+96v they as near as dam = the inverter output voltage.
I will certainly try a lamp across it and check for relative brightness. When we finished cruising in October I certainly don't recall any problems with the TV/DVD player (main item for my Capt that must work!). Working on the basis of "if it is not broken don't fix it" I might leave it alone. However what about the earth connections from the sockets I take it that they should all be connected to the hull and the AC feed, from inverter to the sockets connected via a RCD as you mentioned?
Again, thank you all.
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Not the question you are originally asking, but the view on here in the past is that there are issues with using an inverter on a boat if the neutral of the output is not bonded to earth. It is sometimes possible to add this on inverters that do not have it, but IIRC, not every inverter can be modified to be suitable.
Clearly from the information quoted above, yours is not earth/netral bonded, and this may be something you should be concerned about.
I have just done a search for "+earth +neutral +inverter +bonded", and it brings up a few old threads. Quite a few, unfortunately, so you might have to read a few to see what I'm referring to.....
Trust Gibbo's view on this, and be rightly suspicious of those who disagreed with him......
Thanks for the comments.
A little bit more information:
Inverter Earthing: The information supplied with the inverter states "In a boat, the earth terminal should be connect to the existing grounding system, which may be the hull of the craft".
Voltage Measurement: Again the information states "AC output voltage values are RMS voltage readings.
Meter Spec: The specification for my digital multimeter states " Displays effective value of sine wave (mean value response). This I take to mean RMS values measured. If I use this meter to measure the voltage at home it reads 240 volts, the domestic supply being also expressed as RMS.
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Not sure why but my inverter, stated as being a 230volt 1000w, is only showing 173 volts at its output.
When I went further I found that:
i) Earth to Neutral reads 76 volts. ii) Line to Earth reads 96 volts.. iii) Battery supply voltage to inverter = 12.5 volts.
There is an earth stud on the inverter case which is connected, via a cable, to the hull.
I give the following description of the installation in an attempt to clarify things, but I accept that it might have little to do with low inverter output apart from the fact that there could be a earth bonding problem indicated by the "Line to Earth" reading showing only 96 Volts.
In a domestic installation the "Line to Earth" reading should be the same as mains voltage and one would expect to get a negligible voltage Earth to Neutral.
Being only 32ft in length we have very few 230 volt appliance and only 3 13amp sockets fitted in the boat.
I have not been able to check fully, but the wiring to the sockets does not appear to have been been done as a ring main. 3 separate 3 core cables have been run to each socket from a junction box. A 3 core flexible cable fitted with a 13 amp 3 pin plug top connects the cables at the junction box to the inverter. I also need to check where the earth bonding for the sockets is connected.
Any comments/ suggestions.
PS The inverter is a quasi sine wave inverter.
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To answer my own question and save time; the best way of getting out is not to fall in in the first place but......
Having said the above, I know someone who is concerned about getting back on the boat from such an accident. Having fallen in myself I could not believe that my arms did not have the strength to allow me to pull myself back on to the boat. In this case, I was able to walk to the bank and managed to get out on my own whilst my wife took care of the boat.
What then is the best and safest method of getting back on board?
Us a ridged ladder? Using a ridged ladder, if the boat is not against a mooring, would surely cause the boat to move away when the ladder is deployed?
Folding Rope Ladder? I have seen a short rope ladder that folded up into a bag when not in use, but how practical and effective is such a device?
Comment and advice please.
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I use a device intended for an electric drill. I got the tip from another boater (whilst waiting in the rain at a tunnel some time ago) which was to use the steady arm that come with an electric drill. These are the type that clamp around the drill on the front bearing casing just behind the chuck. Mine now clamps around the tiller arm, at right angles of course, the handle of a golf brolly after being trimmed down a little just pops into the handle of what was the drill steady.
I find the problem when in use comes from the wind and low bridge holes. Because the brolly handle just slips into the "steady", the wind can catch it and you can loose it, but with bridge holes I just lift it out until I am through. On straight bits or when forced to wait in the rain it is a boon. I stand beside the tiller arm, under the brolly when in use, and have not found it a problem. But like most things when boating, you have to use it sensibly.
I thought the problem of being hit by a tiller arm occurred mostly on boats with a trad stern. The tiller arm on these boats being longer than on a cruiser stern seems to encourage boaters to stand outside (or perch on the sides) right on the edge of the back deck and often leaning out when turning, this action to give them more leverage on the tiller?
David.
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Again I say thank you for all the tips and advice on this topic.
Can I now share a few bits of information on and off topic so to say:
1:Whilst searching the web I came across an excellent site, sorry but I can't get the link to work so here it is in long hand.
"www.the-river-thames-co.uk". This is packed with all sorts of practical information concerning boating on the Thames.
2: Pursuing advice from members, I contacted the web site of "visitthethames". They have now emailed me with the following:
"It is advised that Narrowboats visiting the River Thames carry two anchors, so they can have one either end of the boat."
3: In another thread concerning mooring lines and the Thames, members were recommended to visit the site of "tradline.co.uk". Another member had previously responded that the links on tradline site don't work, that was also my experience. On contacting tradline by phone they are aware of this problem and advise that firefox browser, for some reason, mishandles the search. I use firefox hence my failure, however when I tried MS Explorer it worked fine and it is also a very good site and the staff, on the phone, very very helpful.
David.
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Thank you all for your comments I am most grateful.
After further thought on this we have decided to go via Oxford downstream (turn at some point probably Windsor), come back upstream to the Oxford/Lechlade area.
We did attempt a trip to the Thames in 2006, got to Hillmorton, illness and the advice from Rugby Hospital A&E,forced us to abandon the boat on the moorings there and come home by road. We did not see the boat for about 12 weeks, so we never made it to the Thames. We hope for better things this time.
The comments about single handed/disabled were helpful. On the subject of mooring; unless we can get close to the bank and it is reasonably level, my wife has to stay on the boat. From what little experience I have had of rivers, I know it is not always possible to get these conditions, but does anyone have any suggestions about places to moor. Or would it be better to restrict our selves to certain areas more than others.
Just one more point, I have been reading on the forums about the Thames. As we shall be keeping away from the tidal bits is an anchor on the none-tidal section mandatory/essential?
By way of additional information. Our boat is a 32ft steel narrow boat with a 27hp 3 cylinder diesel.
Thanks again.
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I have read somewhere that if one had the choice it is better, on rivers, to go up stream rather than down. I wonder what the view on this is if applied to the Thames?
To get to the Thames I shall be cruising down from Cheshire passing Coventry thence to Braunston. At this point if I was going to go Up Stream on the Thames I would go via the Grand Union coming on to the Thames via Brentford.
Down Stream route I would enter the Thames at Oxford. We would then have the the option of cruising say to Windsor turning then heading up stream back to Oxford then home.
I shall not be making this trip on my own, but the other crew member has restricted movements so to all intents and purposes I shall be single handed. As to the length of our trip, time is not a factor as we have long ago beat the "retirement trap".
Any comments/advice would be most welcome
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Hi. As the one who posted this thread. Having just returned from 2 weeks on the Llangollen (August 2010) thought someone might be interested in our experience.
From what I had read here I expected to be faced with "wall to wall boats" on the canal but I was very pleasantly surprised at the ease at which we were able to move.
Grindly was a problem going up, we did encounter long delays but the sun was warm and we had no need to hurry and it soon sorted its self out.
As to direct problems with other boaters, rather than that being from hirer boats with their inexperience, it seemed to come from private boaters (of which I am one) usually being impatient with others.
I found the stretch from Trevor to Llangollen the most problematic. We draw some 26/27inches and it was hard going because of the shallow depth, but it was my choice to go.
Going up, the worst place was before the bridge at Bryn Howl. Just before the bridge it bends to the right and then a sharp turn through the bridge to the left. On the off side, having come through the bridge, at least 3 boats had stopped, I think to check that they could go forward in the direction of Trevor, but this restricted my movements through the bridge and I was well and truly aground for some time.
The other bad experience was being overtaken by the trip boat on its way back to Llangollen. He took the water and me with it and smashed me against the bank with an almighty bang. At least one other boat had the same treatment. Having said that; the BW man at Llangollen gave me some good advice. Going down to Trevor, "follow the trip boat down as the steerer does not take any prisoners", and so it proved to be the way was cleared for us.
In all it was great. We found that away from the "hot spots" there where plenty of very good 48hr moorings.
A trip down the Montgomery was very worth it. Just one difficulty though here. Coming up, there was a queue for the locks and there where very few holding places for boats. People had no alternative but to take risks trying to keep in line and allow boats coming down to pass. The lock keeper says that he has told his bosses that there is a serious risk of injury to people and damage to boats because of the lack of safe holding places; but they appear not to be interested.
Thinking of going; I would certainly go again.
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I have read here that in "August the Llangollen is like being on the M25 in rush hour."
With that in mind, and taking into account we are not tied to time, what are the busy/trouble spots on the Llangollen in August i.e. what days and times should one avoid the difficult bits when it comes to moving?
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I have read recently of a boater being prosecuted for spilling diesel into the canal whilst attempting to fill the fuel tank on their boat from small drums.
Having attempted the same thing myself recently, does any one have any suggestions of how this operation can be done cleanly, not only from preventing the inevitable oil spillage, but also to take the backache out of the job?
DavidK
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Just came across this thread, not sure if the cure/solution was found?
I am also not sure if this thought will help, but here goes.
When I was at sea, in the days when the majority of ships were DC powered and used insulated lead and return wiring, on our main switch board we had "earth" lamps. They worked like this.
If the ship was free of earths, both lamps would be on in equall brilliance. In the event of a leak to earth, say on the positive side, the lamp connected to the negative supply would glow brighter than the positve lamp or if it was on the negative side the other lamp would be brighter. It was then a matter of isolating each section of the electrical system, breaking it down step by step. In our case, the earth leak was usually traced to any of the outside lighting/nav lights or deck sockets that we suspected especially if we had experienced bad weather. It was amatter of great pride to keep your ship earth free!
Below I describe the simple circuit for the "Earth" lamps
Two lamps of the correct voltage and of the same wattage were connected in series.
One end of the ciruit was connected to the main negative whilst the the other end was connected to the main positive.
From the mid point, between the two lamps, a center tap wire was connected to the ships plates i.e earth.
Just a thought.
DavidK
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Hi..
I've always painted my hull with Comastic paint, when I first did it the price difference was very little over normal tar paint.now it's much dearer. I was told originally that once i'd used comastic I could only ever use the same over the top, but a chap recently told me that I can paint any tar paint over it.
Anyone know for sure which is right?
Thanks..
Can't really contribute to what paint can be used over what paint, but a word of caution about Comastic.
We had shares in a new boat and being one of the first "owners" to take the boat out after a weeks cruising I decided to touch up the black paint above the water line. It was Easter time, we were at Anderton, the sun was shinning. I found some black paint in the locker and so I started to roller the paint on. As usuall passerby gave me some stick, all very good humored and I was enjoying myself. I did not think for one moment I could be in any danger as I was out in the fresh air and was only at it for about an hour.
About 3 am in the morning, I thought I was dying. In fact, according to the doctor, that could easily have happened. I was ill for over a week with suspect liver and kidney problems all because of my use of Comastic. Much later, contacting the manufacturer, they said their product should only be applied when using some kind of air pressure mask.
Do be careful. It might do what it says on the tin, but it could also give you an unwanted bonus.
Davidk
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When it comes to the boat not being used so much in the winter months, is it advisable to change the engine oil and filter before the winter sets in or after?
I seem to recall reading somewhere that with a diesel engine if it is left standing with used oil in it, there is a danger that lubricating properties can break down. If I can, I try to have the occasional " out of season" cruise, Christmas Eve and New Years day at least, at other times I run the engine for a couple of hours at least each month until the weather improves.
What is the best practice to adopt on this please.
DavidK
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Thanks Nick
I think I'll wait and see how we get on in November! - We have a clear view of the Winter Hill mast from home (30 miles away). At the moment the analogue signal is better than digital. With digital the audio and video signals are usually out of sync.
Phil
I think the wait and see approach is the right approach, it is certainly what I am going to do.
A local supplier of all things digital, tells me that currently TV signal strength is set low but; when the change over comes, (just like when the revolution comes) signal strength will be doubled. That he said will be the time to see if you need anything more than the good old coat hanger!!
Davidk
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I dont think there is a best method. Each have their advantages and disadvantages. You should probably decide how you will use the boat and then see which method will best fit your needs or find a boat you really like and live with what it has got.
I like this approach as they say you have to be in it to win it. Or unless you try it you will not know what suits you best.
Our boat is 32 ft and has a calorifier. We find that the water get hot very quickly and is still hot enough for dishes etc the following day without running the engine. But if you want a shower then you need the engine to run. That is not to much of a problem because depending on your current draw and the batteries you do need to run the engine to charge.
On of the problems with a small boat is the space available to fit such a thing as a calorifier. Ours is placed horizontally under the rear settee, but of course we loose storage space.
An instant gas water heater is another possibility but I understand they do need to installed and maintained correctly.
But, we like what we have.
Davidk
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It is generally accepted that 100a is the normal for a v belt BUT that is if you are using the small " car size" pulley originally on the alternator ,
Gear the alternator for 12000 rpm at your max engine revs.
I feel you fall into the common trap of thinking if you upgrade the alternator it will charge your batteries faster ...it will not ...the 70 A is its oultput to resitive loads ...lights and the like not charging loads ...you will be unlikley to exceed 25 A if the battery is well down and this will fall off rapidly as the charge comes up ....have you seen a battery charge at 100A ? Gas and fume and heat ...no no
Please . no body shout but.
Reading this thread I was reminded of my own setup i.e. I have a 60 amp alternator and wanted to fit a bigger (more amps) unit.
Having checked, because of the compact design of the engine, this is not possible without major re engineering. So could I get more amps from the existing unit by simply changing the alternator drive pulley?
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The elbow that goes into the engine water pump is the primary feed, the return should come from the thermostat housing into the top of the heat exchanger somewhere?
As there only appears to be one water pump, it looks as though what is normally reffered to as the primary and secondary circuit are joined? So even if there is a shell inside the heat exchanger, it may have had the tube removed?
This is sort of confirmed by the fact water runs out of the heat exchanger when you remove the cap on the header tank.
What worries me is if it is in fact a single system, I would expect the bottom of the skin tank to go direct to the engine water pump and the top of the skin tank to come from the heat exchanger. I cannot see how your existing system would work on convection as it doesn't sound as though there is anything to circulate the water through the skin tank?
Of course it is possible that the apparent shell inside the exhaust manifold is arranged to circulate the water through the skin tank too!
Hi RobinJ. Thank you for your comments the fact that you expressed some "worries" ("What worries me") about the system led me to contact the the Nanni Dealer AR Peachment. I have done this in the past by phone and email but they never respond. But this morning was very different. I described the current installation to a very knowledgeable gent who was most helpful. Surprise surprise.
His Comments:
Heat Exchanger: For a "fresh water system"; the 2 connections we have from this unit to the skin tank are correct. There is also a pipe from the HE connecting to the belt driven water pump on the engine.
Engine Water Pump: On this engine/system there is only one pump for coolant circulation. The impeller on the pump protrudes from the back of the pump into the water jacket of the engine and circulates the coolant around the system. The Pump has 2 outlets, flow and return, which connect to the calorifire/heating.
Expansion Tank; (In my case Orange Juice Bottle). Apparently different installers do it differently! But it's satisfactory to simply take a pipe from the HE and simply place it in an unpressurised container (orange juice bottle) to catch the expelled coolant. The design of the standard cap does not allow for the coolant to be drawn back into the system.
Header Tank: Again different installers follow different practices with regards to header tank installations. One of the reasons for the header tank is often to give a greater height above the calorifire to increase flow through the unit. The tank would also allow for any air in the system to vent in to the tank as well as for topping up, for this, any coolant that was in the orange juice bottle just needs to poured into the header tank this would stop over topping.
The final note was that as he understood the details I had supplied on my system. although it had one little particularity (the connections of the header tank), he felt that all was well.
He did suggest that if I wanted, the cap on the HE could be changed to a sealing cap instead of a pressure cap. If this was done, expansion would then need to take place in the header which would then need a pressure cap.
I thought that this was complicated and as he thought it was OK as it is I would leave it.
I hope this is the end of this particular saga?
Thanks to everyone for your help.
David.
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Thanks again for all the informed views and comments expressed in this thread.
My Cap't, aka she who must be obeyed, has a view on this which is " if it ain't broken don't mend it".
She reminds me that the problem developed after I replaced the leaking water hose and then removed the expansion pipe from the HE and made a new connection to the external header tank. Prior to this (she said) everything was OK. So put it back the way it was!!
Reviewing all the comments, you all seem to be following the same kind of thinking.
So now I have a plan for my return to the boat.
1: Check for sure that there is not a second pump in the cooling system.
2: Reinstate the orange juice bottle and make sure the pipe is long enough to reach and expansion fluid there in.
3: Check and make a note of all the pipe connections to/from the HE to the skin tank and other devices.
Finally; run the B.... engine and see what happens.
Watch this space for the next installment.
David.
Here is the latest Info.
Had a an early start and made a flying visit to the boat, sorry about the mixed metaphors.
Heat exchanger. This has four connection points:
i) Exhaust connection. Going to the silencer.
ii) Two hose connections. One going to the top of the skin tank and the second going to the bottom of the skin tank.
iii) Underneath the HE the final hose connection ( remember I can't see this and have to rely on feel) that goes to the front of the engine to the belt driven water pump. This connection starts with a rubber elbow, changes to a right angle bend metal pipe. then changes to a rubber hose to connect to the pump.
Water Pump: Only one pump. fitted high up on the engine, as you would find it say on a car engine, and is belt driven
Header Tank: When I arrived at the boat, I found the header tank looked as if it was nearly empty. Can't remember if I left it like that when I was last there. With out touching the cap on the header tank I removed the cap from the HE. The level there appeared lower than usual, I then removed the cap from the header tank and the level in the HE suddenly increased and overflowed.
HE Expansion tank (Orange Juice Bottle):
Reinstated this bottle. Connecting a hose from the cap on the HE via a small hose direct into the bottle.
Put some coolant into the header tank, started the engine and let it run on fast tick over for about 25 minutes.
No sign of any leaks. Unable to detect anything that would suggest that there is still problem or even if the problem is now fixed.
I guess I will now have to wait until I can go back and take it for a cruise.
Just a point, from what has been said here; the cap on the header tank should this be just a screwed cap, or a pressure cap that the one fitted appears to be?
Thanks again everyone.
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Thanks again for all the informed views and comments expressed in this thread.
My Cap't, aka she who must be obeyed, has a view on this which is " if it ain't broken don't mend it".
She reminds me that the problem developed after I replaced the leaking water hose and then removed the expansion pipe from the HE and made a new connection to the external header tank. Prior to this (she said) everything was OK. So put it back the way it was!!
Reviewing all the comments, you all seem to be following the same kind of thinking.
So now I have a plan for my return to the boat.
1: Check for sure that there is not a second pump in the cooling system.
2: Reinstate the orange juice bottle and make sure the pipe is long enough to reach and expansion fluid there in.
3: Check and make a note of all the pipe connections to/from the HE to the skin tank and other devices.
Finally; run the B.... engine and see what happens.
Watch this space for the next installment.
David.
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Not certain of your arrangement either. (Had an air cooled engine for the last 15 years forgotten what the others are like!). However, consider this.
Does your drinking water taste a little strange? Coolant leaking into the calorifier when engine coolant pressure is higher than domestic water pressure, and back the other way when the cap released.
Thanks again for all the comments on this problem.
Perhaps I should say that the boat in question is a 32ft steel NB built in 1999 with a cruiser stern. I am the 2nd owner of the boat.
The engine space is best described as "compact". This means that I can only look down on the engine and can't get to look at the sides or the crankshaft end. What I have to do is to put my hand down the sides and go on touch e.g. I can't see the starter which is directly under the heat exchanger, but I can feel it.
I have found the engine hand book supplied by Nanni. On the subject of "Cooling System" It states:
"It consists of two different systems: the inner fresh water circuit and the external sea water system.
Fresh water circuit: Consists of a pump operated by the crankshaft by means of V belt, a heat exchanger and a thermostat.
Sea Water Circuit: Consist of a pump, the heat exchanger, exhaust mixer.
The book contains a not very good photo of the front of the engine and shows the belt driven water pump but also another pump described as " sea water pump." I am not sure but when I was "feeling around" I did not feel this pump was there the only pipe I could feel was connected to the bottom connection of the belt driven pump. I am confident that the engine does not take water from the canal or river for cooling purposes.
When I get back to the boat I will try to get some photos. How easy is it to put them on the forum?
David.
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I'm also somewhat suspicious that this is not actually an indirectly cooled engine with a heat exchanger, but may simply not be understanding the info given.
Surely the obvious test would be the number of water pumps present.
If the only one is the normal engine water pump, then the system must surely be direct, and only one water circuit involved, (the water in the engine, and that in the skin tank would then be the same).
For it to be indirect, then as well as the "normal" engine pump there would need to be a second pump, (something like a Jabsco impeller pump ?), circulating the water that goes to the skin tank.
Could David please clarify the situation ?
Alan.
In response to the questions raised by my query, the information is:
Engine: The engine is a basic unmodified Nanni Diesel 3 cylinder.
Heat Exchanger:Never been dismantled to check, but when the cap is off there does appear to be a core fitted to the unit. i.e. you cannot look right down inside because of solid metal object below the neck of the outer case.
The heat exchanger connects to the skin tank by two large diameter rubber hoses, approx outer diameter about 2 inches. One goes to the bottom of the tank the other to the top.
No of Pumps fitted: The only pump in the system is the standard engine water pump mounted on the front end end of the engine, belt driven by the crankshaft pulley and alternator.
Heat Exchange Cap: No identification shown i.e. does not show any indication of pressure value. looking at the cap, there is a spring which exerts pressure on a rubber faced metal disk which when the cap is fitted presses on the opening in the heat exchanger neck thus sealing the opening.
In the center of that disk is smaller rubber/hard plastic round disk, when I compress the spring by hand the larger disk moves back and this smaller disk appears to be anchored to a cylindrical object (located within the area of the outer spring). Presumably, under pressure, the center object expands allowing excess pressure to escape from the exchanger. The rubber seal, whilst it is marked it is complete, it show that it has been seating correctly.
Orange Juice Bottle: The excess fluid expelled from the exchange unit was fed, via a small hose, to the orange juice bottle, however, when the pressure dropped, I could not understand how the excess could be drawn back into the system until such times as I either lost the content of the bottle our poured it back into the header tank. It was this thought which led me to do away with the orange juice bottle and connect this hose direct to the header tank.
NOTE: the juice bottle was not fixed in anyway it just lay on it's side on the port side swim. The bottle cap was not air or water tight, the cap was just pierced roughly to take the pipe which was not long enough to reach the bottom of the bottle.
Header Tank: On my return trip home on the same day, I did only put a small amount of coolant in the tank, just to cover the lower hose connection located on the side of the tank at the bottom.
Tank Cap. This screwed cap is the correct top for the tank. It does have some kind of pressure device built into the cap but does not appear to vent any over pressure within the tank to the outside atmosphere.
The header tank is not an item of original equipment supplied by Nanni. The boat was owner fit out so this tank and the plumbing is the previous owners design. Which I must say has never caused any problems until I replaced the leaking hoses and did away with the orange juice bottle.
Thank you for all your time spent on this and I hope that the above information may enable you to give some more suggestions.
I am not able to go to the boat this week and having topped the system up when I left, I wont know what will have happened until then. I was hoping I would find a leak but I have not.
Thank you.
David.
Inverter
in Boat Building & Maintenance
Posted
Hi Gibbo.
I have been back to the boat and carried out the test you suggested. With the lamp across Neutral and Earth and with a volt meter across the lamp; Meter showed zero volts and the lamp did not "glow".
I take it that it is now OK to proceed and bond the Earth and Neutral together at the inverter?
I have managed to get closer to the location, and it is an RCD that I have on board.
In connection with testing a RCD, is it possible to obtain the details of the tester you mentioned.
Thank you