Split charge relay problem

[NB Willawaw]

The other lesson to learn from this, is to always get the electrician to make a circuit diagram of any upgrade work.

 

Make it a condition of the job.

 

I always provide clients with a soft copy of the revised wiring, when I finish.

 

You currently have a boat sparks who has vanished for 6 months of the year and no idea how the boat has been wired.

 

Everybody is trying to guess how your bow thruster is wired in.

 

If you had been able to publish an "as fitted" wiring diagram, it would be fixed by now.

[NB Alnwick]

Edit:

 

Reply removed as this is a duplicate thread already running here:http://www.canalworld.net/forums/index.php?showtopic=41560&pid=755659&st=0entry755659

 

Duplicate topics merged . . .

 

How bizarre.

 

I didn't intentionally post twice. It looks as though in correcting a typo, I (or the system) has inadvertently re-posted the message.

 

The duplicate topics have been merged but it may be worth checking the first post to see if the typo edit survived the process . . .

[WotEver]

What would make a new VSR pack up?

Almost anything - probably nothing more than sheer bad luck. It could even be a faulty connection to it.

 

And (assuming that's the problem) should I replace it with another one, or get something else?

Without seeing a circuit diagram I don't think any of us can really take this any futher. I do agree with others that you appear to have an uneccessarily complicated system so without seeing how it's actually wired, it's all guesswork.

 

With the 'more normal' layout of BT batts at the front of the boat you don't even (necessarily) need a split charge relay, dependant upon on how small the interconnecting cables are from front to back, and if you have one it absolutely doesn't need to be a VSR, simply wired 'on when engine running'.

 

Tony

[blodger]

Thank you, that sounds encouraging.

 

I have an old 30A charger knocking around. I think I'll just connect that to the BT batteries as I haven't a clue what to short. The various items on the main electrical panel are squeezed in fairly tightly and it's hard to know what's what.

 

What would make a new VSR pack up? And (assuming that's the problem) should I replace it with another one, or get something else?

 

VSRs are usually pretty reliable iy's more likely to be the connections to it preventing it working which seem somewhat complicated and tortuous in your case; I am in agreement with Bob 18. I think that ultimately effective repair is likely to be a simplification of the existing along the lines alluded to in posts.

 

Yes in the interim get the batts charged and salve them from sulphating up

[WotEver]

... the fact that its not connecting charging to the 24 volt battery suggests its the isolation contactor that's failing, and that there is some interlocking that gives you the repeated tries.

Not necessarily, Bob.

 

Firstly, the contactor arrangement doesn't have to completely disconnect the BT batts from the charging circuit; it only needs to disconnect one of them and put it into series with the remaining one.

 

Secondly, if the whole parallel-to-series contactor arrangement is powered by one of the BT batts then the machine gunning will be because as soon as it's connected the BT pulls the batts below the hold-in voltage.

 

However, because we don't have a circuit diagram we have no way of knowing if either of my above assertions are correct.

 

Tony

[sebrof]

I don't think the system is "unnecessarily complicated". Larger bow thrusters tend to be 24V anyway, and this switch allows me to have a single charging system for both my 12V domestics and my 24V BT batteries.

 

There isn't a shred of evidence at the moment that the switch is responsible for the problem.

 

Big bow thrusters use a lot of power. It is good to be able to use shore power to charge them, and not have to rely on the engine alone. And, of course, the solar cells can also charge both systems. The switch facilitates this at low cost.

 

I doubt if there is a cheaper way to achieve what I have, and (as stated) there is no evidence that there is anything wrong with it.

 

But we shall see....

 

BTW, Tony, I think your assertions are correct.

 

Incidentally, I think I will get some spare fuses while I am about it. There are a number of 100 amp Buss fuses in the system. Is there a good place to get these at reasonable cost? The ones on Ebay mainly seem to come from America.

[Bob18]

As you say, without the circuits we are all trying to find the candle in the coal cellar, and someone's shut the door behind us.

 

Another question (and probably a physically difficult one to answer) Does the charging system make any attempt to charge the bow thruster battery - it MIGHT be possible to watch the voltage on that battery as the engine is started and revs up - probably a two person job.

 

Process is something like:

Turn the Victrons off for a few hours before you start this, so the batteries are nicely rested.

One person connect meter to the battery terminals with the engine stopped, note the battery voltage, other person starts the engine while first person watches the meter.

Stop the engine, move the meter to one of the battery outputs from the VSR and repeat the measurements

Stop the engine, and do the same for the other battery(s)

A moving coil meter might be better than a digital one - you are looking for change in voltage, not the absolute voltage, but it can be done with a multimeter.

Only run the engine for a few seconds each time - we are looking for changes, not absolutes.

[NB Willawaw]

If Bob, Tony and co manage to fix it for you at distance and save you the expense of paying a professional to do the job, will you put £25 in the RNLI box ?

[sebrof]

If Bob, Tony and co manage to fix it for you at distance and save you the expense of paying a professional to do the job, will you put £25 in the RNLI box ?

 

I have been putting £100 a year into the RNLI box for over thirty years as a member of Shoreline, and I don't suppose another £25.00 will break the bank.

 

As you say, without the circuits we are all trying to find the candle in the coal cellar, and someone's shut the door behind us.

 

Another question (and probably a physically difficult one to answer) Does the charging system make any attempt to charge the bow thruster battery - it MIGHT be possible to watch the voltage on that battery as the engine is started and revs up - probably a two person job.

 

Process is something like:

Turn the Victrons off for a few hours before you start this, so the batteries are nicely rested.

One person connect meter to the battery terminals with the engine stopped, note the battery voltage, other person starts the engine while first person watches the meter.

Stop the engine, move the meter to one of the battery outputs from the VSR and repeat the measurements

Stop the engine, and do the same for the other battery(s)

A moving coil meter might be better than a digital one - you are looking for change in voltage, not the absolute voltage, but it can be done with a multimeter.

Only run the engine for a few seconds each time - we are looking for changes, not absolutes.

 

Bob,

 

I have a Smartguage, and that shows no change to the BT batteries when I put the chargers into bulk mode. It shows a massive change to the domestics, of course.

 

I really don't think I am getting anything through the VSR, but I will try your suggestion with a voltmeter on the BT batteries.

 

Thanks

[NB Willawaw]

At narrowboat prices, £25 is only about an hours labour, so thats a cheap fix if they cure it for you.

 

I have been putting £100 a year into the RNLI box for over thirty years as a member of Shoreline, and I don't suppose another £25.00 will break the bank.

[Bob18]

Lets have a think what we are trying to achieve, and what we've got as "hard facts".

 

1 Some time ago the system worked, both the domestic and bow thruster batteries were being charged, and the bow thruster worked.

2 Someone came along and did some modifications.

3 The bow thruster batteries were reported as being in a good state of health.

4 Since then the domestic batteries have remained in a good state of health, and are being charged.

5 There are two "boxes" in the system, first a VSR to direct the charging volts and amps "in the right direction".

6 Are we right in assuming this is still in the same place as it was before the modifications?

7 The second is a "box of tricks" to re-wire the bow thruster battery from its "normal" state - 12V/charging to its working state - 24V/bow thruster.

8 Are we right in assuming this is still in the same place as it was before the modifications?

9 Are the batteries in the same place as they were before the modifications?

10 First symptoms of a problem was the bow thruster not working properly.

11 How long after the modifications was this (hours/days/weeks/months)?

12 The bow thruster batteries are in a state of discharge, and don't appear to be getting any more charge.

 

 

What do we want to achieve?

We want to be able to charge both the domestic and bow thruster batteries from the available sources of charge.

(preferably without spending much/any money)

 

 

Warning - "bright idea":

 

There is one way we haven't considered - replace the complex VSR and "re-wiring" boxes with a DC/DC charger. The bow thruster only runs for a few minutes at a time, while in that time it draws a lot of current the total amp-hours drawn isn't that high. (Lets say the bow thruster draws 200A, and runs for 6 minutes, that's only 200x0.1AHrs = 20AHrs). So we don't need a particularly massive dc/dc converter to take the 12v from the domestic battery, convert it to 24v and charge the bow thruster battery with that.

 

The price varies form about £140 to "the sky's the limit" depending on the badge, the output current and what the manufacturer thinks they can get away with. Given the low duty cycle, and the small charge requirement I'd go to teh bottom of the price range, for example http://www.power-store.com/view-item.asp?itemid=1270&id=209& looks a "good starter for ten" and lists at £140 (which is about the list of a VSR and a very relays and contactors).

Advantage - its a lot simpler than trying to do the re-knitting, no split charge (high amps) relays to worry about. A pair of 6mm wires from your domestic battery to the dc/dc converter, and a pair of 6mm wires from the converter to the 24v battery, which stays wired as a 24 volt battery all the time...

[sebrof]

Lets have a think what we are trying to achieve, and what we've got as "hard facts".

 

1 Some time ago the system worked, both the domestic and bow thruster batteries were being charged, and the bow thruster worked.

2 Someone came along and did some modifications.

3 The bow thruster batteries were reported as being in a good state of health.

4 Since then the domestic batteries have remained in a good state of health, and are being charged.

5 There are two "boxes" in the system, first a VSR to direct the charging volts and amps "in the right direction".

6 Are we right in assuming this is still in the same place as it was before the modifications?

7 The second is a "box of tricks" to re-wire the bow thruster battery from its "normal" state - 12V/charging to its working state - 24V/bow thruster.

8 Are we right in assuming this is still in the same place as it was before the modifications?

9 Are the batteries in the same place as they were before the modifications?

10 First symptoms of a problem was the bow thruster not working properly.

11 How long after the modifications was this (hours/days/weeks/months)?

12 The bow thruster batteries are in a state of discharge, and don't appear to be getting any more charge.

 

The BT arrangments are original. The VSR, domestic batteries, chargers, etc., are new. Previously there was just a manual switch.

 

What do we want to achieve?

We want to be able to charge both the domestic and bow thruster batteries from the available sources of charge.

(preferably without spending much/any money)

 

 

Warning - "bright idea":

 

There is one way we haven't considered - replace the complex VSR and "re-wiring" boxes with a DC/DC charger. The bow thruster only runs for a few minutes at a time, while in that time it draws a lot of current the total amp-hours drawn isn't that high. (Lets say the bow thruster draws 200A, and runs for 6 minutes, that's only 200x0.1AHrs = 20AHrs). So we don't need a particularly massive dc/dc converter to take the 12v from the domestic battery, convert it to 24v and charge the bow thruster battery with that.

 

The price varies form about £140 to "the sky's the limit" depending on the badge, the output current and what the manufacturer thinks they can get away with. Given the low duty cycle, and the small charge requirement I'd go to teh bottom of the price range, for example http://www.power-store.com/view-item.asp?itemid=1270&id=209& looks a "good starter for ten" and lists at £140 (which is about the list of a VSR and a very relays and contactors).

Advantage - its a lot simpler than trying to do the re-knitting, no split charge (high amps) relays to worry about. A pair of 6mm wires from your domestic battery to the dc/dc converter, and a pair of 6mm wires from the converter to the 24v battery, which stays wired as a 24 volt battery all the time...

 

That's food for thought. Sounds like a good plan if the VSR or switch is knackered. It's certainly simple, and I could probably put the batteries in the bow and sell the cable.

 

I hadn't previously taken on board the fact that the power used by the BT is actually quite small.

 

Thanks again.

[bizzard]

At narrowboat prices, £25 is only about an hours labour, so thats a cheap fix if they cure it for you.

Steady old chap steady.

I'd say stick the batteries up the front too,no doubt at all,after the test.

For £20 Trix,ll fix it.

 

Ps Sorry Willawaw,this was meant to be for post 34.

Edited September 30, 2011 by bizzard

[Bob18]

Everything is pointing towards the modifications not being done correctly :-((

 

Either not correctly wired up, or wrongly rated components used.

 

 

 

 

 

 

 

If either, or both, of these proves true I'm sure Tony will join me in supplying you with a bit of wire and instructions so you can "string up" the absent electrician to something suitable... (Tony, do you have an old hand cranked magneto tester to hand?)

[bizzard]

Or do away with the electric thing,and weld in a transverse Phutt-Phutt tube.the extra warmth from a stove up front now winters approaching must be beneficial.

[WotEver]

(Tony, do you have an old hand cranked magneto tester to hand?)

Just as good, I have an old Megger somewhere

 

Gee, last time I used a mag tester was on the Gypsy Major in Tiger GA-CDC...

 

Tony

 

ps - I agree with the 'update' breaking the system. I suspect the BT batts have never charged since the work was done.

[NB Willawaw]

From Post 1.

 

I should be grateful for some advice.

 

My bow thruster does not appear to be getting enough power from the batteries (2 large 190AH lead acid jobs). It has been gradually declining during the past few months, and now just gives a grunt and gives up when I switch it on.

 

A few months ago, I had new electrics installed.

[WotEver]

From Post 1.

Indeed.

[sebrof]

Just as good, I have an old Megger somewhere

 

Gee, last time I used a mag tester was on the Gypsy Major in Tiger GA-CDC...

 

Tony

 

ps - I agree with the 'update' breaking the system. I suspect the BT batts have never charged since the work was done.

 

It is what I have been wondering since Bob's post pointing out how little energy a BT uses if only deployed for a short time.

 

It certainly hasn't had a lot of use.

[Bob18]

Its a common mistake. Lots assumes that a bow thruster uses lots of energy. In terms of amps per second they certainly use a lot, but since they are only on for a few minutes at a time it doesn't add up to much.

You do however need a decent bit of cable between the battery and the thruster otherwise the cable will get very hot, even in the few minutes of use.

 

The reason for bow thruster manufacturers give a particular size of battery is so during the few minutes of use the battery voltage will not drop too far in that couple of minutes of use - not quite like the 400A for twenty minutes to an hour I used to inflict on the batteries when hauling cars/lorries/lumber out...

[sebrof]

The batteries are charging. And the BT is working (for a second or two).

 

The Smartguage reports a voltage of around 13.1V from the BT batteries now, so whatever the state of the batteries, the problem is not that they are dud.

[WotEver]

The batteries are charging. And the BT is working (for a second or two).

 

The Smartguage reports a voltage of around 13.1V from the BT batteries now, so whatever the state of the batteries, the problem is not that they are dud.

I think that's what we all expected. It won't have done them any good, going without charge for a few months, but it certainly shouldn't have killed them.

 

Tony

[bizzard]

The batteries are charging. And the BT is working (for a second or two).

 

The Smartguage reports a voltage of around 13.1V from the BT batteries now, so whatever the state of the batteries, the problem is not that they are dud.

Are you sure the B/t's props not fouled up,or motor seizing up?.

Also if the small gauge cabling's terminals from the switch and soforth are of the crimped type, you know Yellow,blue red ect. As i find these time and again have faulty or lose connection between wire and crimp,they don't like vibration.I hate em.i always solder all mine,and if i do any wiring work for anyone always solder,no come backs. bizzard.

[bizzard]

Are you sure the B/t's props not fouled up,or motor seizing up?.

Also if the small gauge cabling's terminals from the switch and soforth are of the crimped type, you know Yellow,blue red ect. As i find these time and again have faulty or lose connection between wire and crimp,they don't like vibration.I hate em.i always solder all mine,and if i do any wiring work for anyone always solder,no come backs. bizzard.

Go about jiggling all the wires in their crimps checking for loseness.

With your Victron unit ect you've probably got hundreds of the little horrors.

If so an antidote for your ''getting bored quick''thing could be solved.Why not during the winter,replace em all with solder terminals,(one by one though).

[WotEver]

Why not during the winter,replace em all with solder terminals,(one by one though).

Sorry Bizzard, but that's really bad advice. We've been here before, but why do you suppose that all military, aviation and space programmes specifically insist on crimped connections only? Put a soldered connection beside a correctly crimped connection on the same vibration rig and the soldered connection will fail first. Every time.

 

Tony