Sea Panther Series 1 and 24v starting on Centaurs

K

KieronRyan

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23 May 2005
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www.bibble.co.uk
My centaur (753 Nore Sand) is fitted with a seapanther, which I have
rebuilt. Can anybody explain the 24v 4 position switch used the change
the batteries from 12 to 24 and also the function of the CAV voltage
controller connected to the CAV 24 generator.
Am I correct in thinking that the batteries can only be charged in 24v "mode" and therefore I can not have a reserve battery ?
I can not find a drop down resistor.


Kieron
 
To be honest I really don't know anythig about these items however you mention a generator. That sounds like an old dynamo generator ie not anj alternator. If you have any trouble with it or simply need more power then a truck 24 volt alternator and regulator would be well worth fitting.

24 Volt system is well worth retaining especially if the starter is 24 volt. It results in lower current hence less voltage drop and better starter performance and is essential for big diesels.
I can't quite picture how a 12/24 volt switch would work unless it was to shift the batteriews to paralell configuration for running services. This would mean you would have to shift to 12 v for running radios. Lights could either be 12v or 24 v however you would have to be on one or the other at any given time. ie no charging when on 12 v. I am guessing it is a pretty old system built before modern 24 to 12 v converters became available. If you got a converter to supply 12 v from 24 then I think yiou could throw away the 12/24 switch.
(If you keep the switch you need a contact to disconnect the 24 v line to starter generator etc. from the top of the top battery and switch that terminal to connect to the + termiinal of the bottom (one side earthed) battery. The bottom _ve of the top must be connected to the _ve of the bottom battery in lieu of being connected to the top+ of the bottom battery.
The + of the bottom battery now becomes the 12 v supply to services. NB it can always be a 12 v supply point at any time but you run the risk of discharging one battery more than the other. OK for small loads short term.)
The simplest arrangement is to get a 24/12 v converter from a motor spares shop. This will supply 12 volts to your radio etc. Run all the lights on 24 volt and throw away the 12/24 switch.
An alternative is to get a 12/24 comverter with an output of exactly 13.75 to 14 volts or find one you can adjust the voltage (internally) on. This can be used to charge a 12 volt services battery so you run everything from the 12 v services battery except the starter/ generator. Any lower voltage from the converter ie 12 v wi9ll not charge your extra battery.
If you do that howefver I suggest you get a 24 volt Voltage sensing relay to isolate the 24/12 converter otherwise you will tend to charge the 12 v battery from 24 v battery even when engine is not running which will discharge 24 v battery. In lieu of the VSR you may have a 24 circuit/switch which is only on when engine is running or operate a relay from an oil pressure switch. Anything to automatically stop the 24/12 converter from charging the services battery when the 24 v is not being charged. ( diode isolator won't do this job)

Of course it is nice to have an isolated services battery so you can always get an engine start however with a little discipline you should find it unlikely that you discharge the engine 24 volt battery if you are using it for lights etc because of the lower current needed for starting and for lights. That depends a lot on your boating style and habits. ie if you run a fridge get an extra serces battery.
A modern 24/12 converter actually switches the 24 volts into a transfomer so that you get twice the current out at 12v that you put in at 24v less inefficiencies 80%. An older series regulator type converter simply dissipates half the voltage in heat so 10 amps in at 24 v gives 10 amps out at 12 volts with 120 watts wasted in heat. This type can automatically vary its internal resistance to ensure 12 v out regardless of current drawn. A resistor of course dissipates the power in heat again except that at high currents you get less than 12 v out while at small currents you get too much out nearly 24v. So resistor may be OK for lights on one switch but no good for radio. There is a lot more story here and you can actually make a series converter type for small currents quite cheaply.
Have I confused you. Much of this is guess work. PM if you want regards olewill
 
Hi Kieren

Welcome to the forum. I have exactly the installation you have: 24v Sea Panther in a Centaur.

I have two isolated systems. This is not ideal since there's no chance of changing over if the engine battery is flat.

I have a 24v side with a 24v alternator fitted to the engine & an external regulator. This is the standard arrangement shown in the Sea Panther manual. I have 2 x 12v batteries in series dedicated to the motor.

I also have a separate alternator from a 1.3l Fiesta mounted remotely with another belt to drive it. This is not ideal since it's mounted on the engine mounts & any engine vibration creates load on the alternator. However since it's a standard auto part it's cheap to replace & seems fine with no wear on the bearings after 5 years. This charges a single 12v battery dedicated to the domestic side & mounted under the port side saloon seat (B layout).

There is no change-over switch. I just have individual isolator on both banks.

The only complication with this arrangement is switching the field winding on the 12v side with the engine key. As the boat was when I got it, this was done by a large croc-clip on the 12v battery - just connect the wire. Not ideal so I've replaced that with a switch. I'm going to replace the switch with a relay to make the whole lot "automatic". Just use a 24v relay that's enegrgised from the 24v starter switch and switches the 12v field winding.

The engine panel is very simple with an extra charge light for the 12v system. This is just a small 12v lamp in series with the field winding.

One comment I'd make immediately about the system is that the starter is prone to failure since it's a 12v starter with 24v across it. I've had the boat three seasons and am on my second starter. I now intend to change the starter as part of the winter maintainance. It's only £29 exchange from the motor factor so it's no problem. In fact for £80 I could carry a spare.

I have looked at an arrangement of 2 x 24v banks & one alternator. This would allow cross coupling if the engine bank was flattened. But, I would need to use a 24v to 12v converter for the domestics. This is not a real problem but if I do it, I'd still keep the 12v alternator fitted with belt disconnected, plus some patch wires to allow the domestic bank to be converted back to 12v quickly if the converter failed.

If you don't have the standard wiring diagram for the Sea Panther, I can send you a copy. PM me.
 
And there was I thinking I was alone in the 24V starter stakes!!

Do you have the pre-ignition heater in the inlet manifold?

My plan is to (having rebuilt the engine... nearly there) :-
1. fit the standard starter motor and try to start it (just to see what happens)

2. If it won't turn over then the situation is Academic, I'll investigate installation of the Pinto starter. It fits but the pinion is wrong. If it turns but won't start I'll invest in a pre-ignition heater from Stephenson Marine (although probably from a Bedford truck) and see if I can't start it with that.

The geometry for the pinion is on the bendix so I can have one made for the pinto starter.

3. As an alternative I could have a second set of batteries with Isolation, wired in parallel to the first set. Start the engine and have a switched mode system.

4. I could install a secondary charging system.

One of the things I like least is the implication of the whole family of batteries they're starting to breed!!

Of course the obvious comment is that this is all getting incredibly complicated and that’s exactly what I didn't want.

The saga continues. Off to the garage now to finish the rebuild!!
 
I have a Sea Panther on a Kingfisher 30.
The Sea Panther was designed to start 24 volt and charge 12 volt, using a 12 volt starter motor, which is an engineering bodge of epic proportions
That said mine starts first time, every time, because it scares the living daylights out of the starter motor - they do say in the manual that you should not crank for more than 15 seconds - mine starts in 2!
I cannot see why Westerley would modify the basic setup to give 24 volt charging.
There should be a thumping great relay which switches to series, when starting via the starter switch, giving 2 x 12 volts= 24 v, and which when started, drops back to allow the batteries to charge in parallel at 12 volts.
According to the manuals which I have, the system was designed for a dynamo, later up dated to a Lucas Alternator, and which in my case has been further uprated to a Bosch 55 amp alternator.
If we have a running Centaur engine, put a meter across the batteries, when charging, and it will be about 13.6 volts if a 12 volt system and double that if 24 volt.
That will settle the series start - parallel charge debate.
If that succeeds, I have a wiring diagram for the Kingisher, originally typed but now in Autocad format, and which I would not expect to be any different for the Centaur. PM me if you want a copy
 
Hi,
thanks for the input, I have not seen a relay anywhere (Centaur engine bays arn't that big !!) so no change over contacts.

Have you ever tried it 12v ?

Do you have a pre ignition heater ?

could I have a copy of your manuals ?

The hand switch would appear to do the change over betweeen off|12vA||12vB||24v, and the CAV 440 regulator would appear to regulate 24V (according to Stephenson Marine).

I think I need to trace all of this and draw it out...

regards


Kieron
 
Hi Kieron,
good to see you are getting some support here. Dont let Alf or Simon slow you up too much!!
Didn't see your car there yesterday?

Jim
 
I'm closing the engine, or at least I would have had I not broken the water pump inpeller (again) !! Long story needed to move it 2mm so it didn't strike the block and "twang" !

I have jobs I can do, but at the moment everthing is engine/ electrics orientated. So rainy days is engine and sunny days is boat electrics !!

Interesting to see other people having similarly wierd wiring !!

Any suggestions on how to cross reference Ford Part No with Sea panther numbers...

I have the sea panther numbers

__________________________________________________

I'll be down next weekend to try and finalise an electrics plan

regards


Kieron
 
Having posted earlier, regarding the K 30, I have dug out the original manuals, wiring diagrams and handbooks.
The Printed manual states quite clearly that the engine has a 24 volt system using a CAV 24 volt alternator @31 amps.
The actual installation instructions on the other hand states that there is a dual 24 volt start and 12 volt charge system using relays.
There is no mention of any cold starting system, which if like the Perkins system for the 4108, preheates with an electric element a small amount of diesel, which is sucked into the air intake during the starting proceedure.
My Sea Panther starts instantly even in sub zero conditions!
I have therefore the original 24 volts diagram in the Printed manual, a diagram in the installation instructions by Watermota dated 1972, which is typed and hand drawn and this is the hybrid 12 -24 system, and a modern copy on Autocad, including items such as third battery and gas alarms etc.
I have never seen a 24 volt Watermota, and would be interested if we know the age of the engine you have. The Printed Manual is dated 1970, the installation instructions dated 1972, which suggests they switched to 12 volt starter and dynamo(alternator) in 1972, using the relay system.
The relay box by the way is about the size of a fag packet, and it metal clad.
 
My alternator is a CAV 234 (lucas), and we think, from a military spec application.
I have a block box called a 440, yes that's it !!, that's all I know about it !
My Centaur is 753 so we think it's a 72 or 73, most of which ties up with other evidence...

The preheater was much later say '75, but I'm guessing, it's in the watermota book as a drawing for the parts list.

Does your relay box have any numbers on it?

could we do an exchange I'll scan in the watermota book(cost me £15!!) if you'll send me what ever wiring diagrams you have ?

would be very much appreciated !

regards

Kieron
 
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