Relay on battery charging system / tugboat

[lefty51]

Im doing some work for a marina. They asked me to check out the battery charging system, on a tugboat. Boat is very old, and the prints are in dutch. Relay in the charging system starts clicking rapidly, ( sometimes...but not always ) but of course never when Im there to check it. It does not look like a standard relay....probably voltage sensing, and / or current sensing, as it has some electronic devices on the board. Anyone have experience as to requirements for a typical relay for this application ?? ( The relay is also hardwired in, the cover is removeable...but thats it. Obviously I want to change to plug in style, which can be readily changed if need be.
4 wires on the relay....its 24V DC....so basically 2 for the coil, and 2 making and breaking a circuit.
I know this is kind of vague, but im pieceing information together as needed, and make a decision from there. Thx!

 

[waross]

Step one;
Is this an alternator or a generator?

Obviously I want to change to plug in style, which can be readily changed if need be.

If the device in question is a voltage regulator, that is neither obvious nor recommended.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[lefty51]

I believe there is 380 volts / 3 phase / 50 hz supplying the charging system....so this would be an alternator system...correct ?
Generator = DC
Alternating generator ( alternator ) = AC.

 

[ccjersey]

Sounds very similar to most systems where low voltage (especially due to a high resistance connection in the circuit) results in a chattering relay.

 

[PHovnanian]

Now you've got me confused. You have a 24Vdc relay (coil and maybe contacts), but the 380V, 3ph, 50Hz sounds like shore power. Or perhaps a gen set driven off the engine.

I think waross' question about generator/alternator envisioned a charging system much like an automotive or truck system with a dedicated 12V or 24V alternator. While these are AC devices, typically they have a built in rectifier and put out DC at the battery voltage.

While a 380V machine could be considered an 'alternator', the presence of that voltage makes me believe that you have something else going on here. Can you scan in and post the applicable schematics? There might be a few people here that can actually handle the Dutch.

 

[lefty51]

Well, Im kinda glad that somebody else is confused as well.....makes me feel a whole lot better...lol !!
I will see if I can scan the drawing and post it. That would be invaluable.

 

[oldfieldguy]

Sounds like an old electromechanical voltage regulator to me.

Do you find an electronic voltage regulator on the engine's alternator/generator (the 24-volt one... ti's got to be somewhere around there.)

Old marine stuff can be quite confusing, especially when it comes from overseas. there are some very 'creative' approaches to things.

old field guy

 

[itsmoked]

Describe the system in more detail. Is it a big box with shore power feeding it?

A motor generator set?

One of the most common failures in large battery systems is the jumper cables and other power connections. They corrode and become flaky. This can confuse whatever charger is there, be it an alternator or an off-the-line charger. The intermittent can cause things like relay chattering.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[raithrovers1]

Most battery charger systems have the following relays to initiate alarms:
High volts, low volts and mains fail. These are generally controlled by electronic threshold monitors.
If you could post a copy of the drawings as mentioned before then I am sure we can pinpoint what the relay is for and why it may be chattering.

UPS engineer

http://www.powerups.co.uk

 

[lefty51]

Let me see if I can get one of the guys from engineering to scan the drawing, and then I can post in a PDF file.
Will try and get this tomorrow. Yes, its a humbling & learning experience.........

 

[waross]

The tugboats I have worked on had either an alternator or a generator (very old, pre 70s) driven by the engine to charge the battery. This is similar to the alternator or generator on your vehicle.
If you have a static charger fed from a 3 phase source, then you better tell us something about the source as well.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[lefty51]

Here is one PDF file, which looks like power layout ?

 

[PHovnanian]

I see two control positions, one in the wheelhouse and wiring to two solenoid valves for some sort of propeller control. That's as far as my Dutch gets me.
No batteries, alternators or chargers. This must be the wrong page.

 

[lefty51]

Should be able to post the other page today.

 

[lefty51]

Here is the 2nd one.Engineer had some problems scanning the document.....perhaps this will shed some light as to the overall operation. Thx.

 

[waross]

Well the drawing on the left, subject to correction, looks like the starters for three generators, fed from a bus. The bus may be connected to either of two battery banks, "Lader" will be the charger. The relays disconnect a battery from the charging bus and connect it to the charger. Only one battery at a time may be connected to the charger.

Haven Groep literally translates to Harbor Group, Possibly Shore power or shore services (On-board power normally used only in port??).
On the right side of the drawing, we have a 24V bus fed from either of two alternators and/or the harbor group.
There are contactors connecting battery #1 and battery #2 to the 24V bus. When a battery is to be connected to the charger, the #431 or #432 contactor must be opened to disconnect the battery from the main 24V bus. Another contact must close to connect the battery to the selector switch at the charger.
Questions:
Are the battery disconnect switches (#431 #432) manual or magnetic? there doesn't seem to be any control for them, but then the "M" coils do not seem to control anything.
I would expect these relays to be fairly heavy, 431 and 432 must carry normal charging and starting current which will be several hundred amps. They may be manually operated disconnect switches with auxiliary contacts.
The 451 relays must carry the output of the charger and may be larger than most plug-in relays but you may have a very large plug in relay in mind for replacement.
Battery #3 may be charged by the charger but not by the charging bus.
Our next step in trouble shooting is to identify which relay/contactor is chattering.
Can you take a look and tell us what contactors #431 and #432 and relays #451 look like physically and if one of these is the problem relay?
Note; If either the #431 or #432 device is not closing to the full limit of its travel due to age, wear, poor adjustment or any other factor, or if one of the auxiliary switches is out of adjustment or loose or failing, that could cause one of the #451 relays to chatter. (Either one is possible due to the cross connected interlocks.)
A #431/#432 device failing would also explain the intermittent nature of the fault. One time it is operated it seats properly and there is no problem, the next time it doesn't seat all the way home and an auxiliary switch is not operated properly causing the associated #451 to chatter.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[PHovnanian]

Here's what I see:

Two 24V alternators and 24V shore power (havengroep) feeding a 24V bus. A switch (#421) connecting a charger (lader) to one of three batteries. There are two contactors (#431, 432), also controlled by switch #421 selecting either battery B2 or B3 to the main 24V bus. These contactors have some auxilliary contacts that appear to be used for an interlock (preventing both batteries from feeding the bus at once?). There also appears to be a voltage sensing relay within the charger block, possibly tied to the 24V alarm panel (alarmbord).

Where is the relay you are interested in?

 

[waross]

Looking at it again, the "M" devices may be interlocks to the starting circuits so that an engine may not be started unless both battery banks are connected to the bus. Do they have trouble starting when a relay is chattering? If so, then check the auxiliary switches controlling the "M" devices.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[raithrovers1]

OK, starting at the bottom, you have a 380Vac supply from the Hoofdschakelbord (Head Link Board) going to the input of the charger. The charger produces 24Vdc nominal output and also supplies 24Vdc alarm board.
The main 24Vdc goes up to switch 421. If switch 421 is moved from where it is drawn to the first contact it will charge the 420Ah battery through the 63A fuse and distribution board EB4.
If you move switch 421 to the next position it will charge the bottom bank of 200Ah batteries BUT only if the switch 432 is open (supply from alternator) if 421 is closed the auxiliary from the switch opens the battery charger supply.
If you move switch 421 to the next position it will charge the top bank of 200Ah batteries BUT only if the switch 431 is open (supply from alternator) if 431 is closed the auxiliary from the switch opens the battery charger supply.
This is to prevent the charger and the alterantors being operated in parallel.
What is the output voltage of the charger, how many batteries are there in a string and are they lead acid or Ni-Cad batteries?

UPS engineer

http://www.powerups.co.uk

 

[raithrovers1]

Correction on the above post.
If you move switch 421 to the next position it will charge the bottom bank of 200Ah batteries BUT only if the switch 432 is open (supply to starter motor) if 421 is closed the auxiliary from the switch opens the battery charger supply to prevent the charger feeding current into the starter motor when starting.
If you move switch 421 to the next position it will charge the top bank of 200Ah batteries BUT only if the switch 431 is open (supply to starter motor) if 421 is closed the auxiliary from the switch opens the battery charger supply to prevent the charger feeding current into the starter motor when starting.
The M coil on the left hand side does seem to be some kind of interlock. Not sure if it stops both batteries starting the engines or only allows both batteries together to start. From experience I would guess that you would normally choose which battery to use to start rather than use both.
Going back to your initial thread I would still assume that your problem is with a voltage level relay within the charger itself monitoring output voltage and therefore the chattering would mean it is right on the monitoring threshold. I would assume that there are a couple of pots (variable resistors) on this card that set the thresholds.
If you can control the output volatge of the charger (without batteries connected) then I would lower the voltage (with a meter attached to the output). See if the relay starts to chatter. This will be the low volts setting. If not increase the charger voltage if relay chatters this is the high volts threshold. Once you have found the point at which the relay chatters then you have found whether it is a low or high volt problem.
My guess is that when the engines are started and high current has been taken out of the battery, once the charger is re-connected it will go into low volts alarm due to the charger current limiting itself. This would not be a problem as it is how the system is designed.


UPS engineer

http://www.powerups.co.uk