BALMAR MAX CHARGE MC-624 not working

[DITB]

After finishing fixing my hydraulic rudders succesfully, next problem is charging from the engines to the house batteries.

Last time I tried, neither engine (two 40HP Yanmar diesels) drove any charging to the house bank, while they both charged their own 12V start batteries.

Both engines have separate alternators, to charge the house bank. While the engines are obviously 12V, the house system is 24V, hence the MC-624 (24V version). So four generators in total - the two 24V generators are Balmar 60-24-70-SR-IG Alternator 24V/70A, with a MC-624 controller each (still need to locate the one in port side)

I now understand where the expression "I have cracked the case" has come from:



I applied 12V DC to POWER and GND, just to see if it's completely dead or what. Since it's all 24V, I will try that now and see if there's anyone at home in my "cracker box".

These units costs something like 300-400 USD, can it really be that they just crack themselves up? See photo.

I suspect the other unit suffered a similar fate (need to locate it first). Before I cough up with two new units, I want to ask the forum here if I might have done anything wrong. I don't want to install two new units just to see them blow as well.

Thank you, forum.

[smac999]

I wonder if that is from heat? too close to engine?


I have never seen that. put in lots of balmar regs.

[DITB]

Originally Posted by smac999

I wonder if that is from heat? too close to engine?


I have never seen that. put in lots of balmar regs.

It is indeed in the engine compartment, and Hong Kong does get up to 100 F at times, just the ambient temperature.

I had both engines serviced (new oil pans and more) by the local Yanmar dealer, and didn't see if the charging actually worked, during testing. It's a very silly location, difficult to get to on starboard side especially. Just lifting the engines out is a challenge in itself - I wonder if they hit the unit physically in the process (things start to fall into place now). A 300+ pound engine dangling close to the Balmar (yes, it is close on the starboard side), I can imagine they hit it with the momentum of the engine.

I managed to locate the starboard MC-624, and it seems intact. Upon starting the engine, I made a video (after about a minute of running), to see the display codes. No error codes reported, but nothing came up to the house bank itself. Stupid me - forgot to cover the solar panels first or disconnect, that made it harder to track the voltage. Turning on a few high drain items it was certain that the starboard engine did NOT charge the house batteries. I covered most of the panels, and voltage dropped, house bat started to drain.

Now, the almost obvious test is to remove the port MC-624 and place it on the starboard engine - to see if there is any indication.

Btw - forgot to mention - last time I started the engines (for testing, when I also discovered the rudder hydraulic leak), the charging voltage went up to above 30V DC! (24V DC system). I suspect that the faulty (cracked) starboard MC-624 sent some field voltage out (by fault) that triggered the alternator to go bazerk.

I will note down the values of the display from the operational port side MC-624 and post shortly.

Thank you for helping!

[DITB]

Codes from port side engine (functioning MC-624 - although it doesn't charge the house batteries).

This is after a few minutes of running, engine in higher than idle, around 1,500 rpm, for testing.

(The codes below means "Balmar 624, Program P04/AGM, 502 Soft ramp charge, 503 Set Bulk / hold battery voltage.)

Bu and Cu confuse me a bit, however. The book says

BU "Indicates "real time" battery system voltage. Followed by actual voltage reading"
CU "Indicates Calculated voltage (target voltage based on preset program levels). Followed by actual voltage reading."

But then

Bu "Bulk voltage adjustment. Controls the maximum limit of allowable bulk voltage. Starts at value set by bat- tery program currently in use. Adjustment spans from 28.2 to 29.6 volts. To reverse direction of scroll, release magnet and wait for LED to display bu code. Re-activate switch with magnet and release when desired value is indicated."

Cu isn't mentioned, that I can see.

Is that a mistake in the program, or the manual? I checked the video again, it definitely shows "Bu" and "Cu", never "BU" nor "CU"

Anyway, the codes I get (Initially at around 1,500 rpm):

BAL
624
P04
AGL
502
Bu
24.0
Cu
27.0

Subsequent values of Bu and Cu:
23.6 28.6

(program changed to 503, then more Bu and Cu values)

Bu Cu
24.2 28.7
23.4 28.7
23.8 28.7
24.6 28.7
23.9 28.7

After a few minutes of increasing the load and covering solar panels, I ran back to idle ~ 700 rpm, and took values again. The program was still at 503, but now I got

Bu Cu
0.0.0 28.7
0.0.0 28.7

Huh?

[DITB]

I got the MC-624 out from port side, so I can mount it on starboard and try it out there.



Despite the units bought at the same time (according to records), in November 2006 from a local well known dealer, it seems they are different vintage. They are punched 2006/07 and 2010/10, so I guess the broken one was replaced already once (record shows a repair but no parts).

I better find a different mounting location for the starboard unit, seems it lives life dangerously in that position ...

Sorry for all the babbling around, fishing for input AND hope someone else with similar equipment could learn from this some day (especially after I sort it out)

[donradcliffe]

Your Balmar manual is a bit different than mine, but the main thing is to measure the field voltage (blue wire). If the Bu is 24v and the Cu is 28v, the regulator should be putting out in the order of 22v in the bulk mode. If the 22v is getting to the field of the alternator, the alternator should be putting out in the range of 75% of its rated amps, or it is shot.

If you throttle back and the Bu goes to zero, something is definitely wrong with the regulator or the wiring. Check the voltage on the brown wire and make sure it is the same as the battery voltage. If it is lower, trace the brown wire back to the battery--there is a switch somewhere (ignition or oil pressure) and it may be bad.

[bobofthenorth]

Having just gone through this with the 12 volt version of that regulator I can say that you need to do some serious troubleshooting before you start throwing parts at the problem. Past the obvious stuff like loose connections and bad cables take a good look at any oil pressure switches that may be in place to detect a running engine. They do fail and when they do the symptoms can present as a failed reg or alt which is in fact OK. Balmar is pretty clear about the voltages you should see at the regulator but you may have a compound failure - reg + alt for example. You can test the alternator by BRIEFLY jumping 24 volts directly to the field while monitoring the output voltage.

R.J.(Bob) Evans
www.bobandmarilyn.ca

[Nicholson58]

Balmar has good instructions on line. You should print them. Balmar may be able to help you figure out what happened to your units. We have been struck twice by lightening in the last 5 years. Both times we have lost one of our alternators. Most of the diodes were fried. A wrecked alternator could mess with the Balmar. Get your alternators serviced at a place that rebuilds truck alternators. Ours were $60.00 each time for total rebuilds & diode replacement.


When I installed my Balmar charge controller (24 VDC) the instructions said to avoid installation in a hot area, however, the device comes only with a 4-foot or so cable. This would limit it to adjacent to the engine block. I soldered extension wires of much heavier gauge and extended the installation by about 12 feet to put it at the nav station where I can see what's going on.

[Stu Jackson]

Do you have the manual for your regulators? They are available online at Welcome to Balmar.

They have very good trouble shooting details.

Bu is battery voltage measured at the batteries with the battery sense connector on the regulator. Too many people wire them up with the sense wire at the alternator. Because of the possible voltage drop between the alternator and battery bank, the actual battery voltage with the sense NOT at the bank will lose you charging voltage. RTFM which says both will work, but it's just wrong to say either will work.

Where does your sense wire go now?

Cu is what the regulator is telling the alternator it SHOULD be doing, it's the "target" voltage. Also covered in the manual.

Get them out of the engine compartment. Period.

Good luck.

Alternator Regulator Wiring Diagrams - all three http://c34.org/bbs/index.php/topic,4548.0.html

[Stu Jackson]

Originally Posted by DITB

Last time I tried, neither engine (two 40HP Yanmar diesels) drove any charging to the house bank, while they both charged their own 12V start batteries.

I still don't understand from your descriptions how your electrical system is designed so that the alternators charge the house bank.

How is it supposed to work? Do you have a combiner, echo charger or other VSR? Or do you use manual switches?

[smac999]

Originally Posted by Stu Jackson

I still don't understand from your descriptions how your electrical system is designed so that the alternators charge the house bank.

How is it supposed to work? Do you have a combiner, echo charger or other VSR? Or do you use manual switches?

he has 2 alts per engine. each direct connect to start battery and house battery.

[DITB]

Thank you for all the feedback.

Yes, I do have the manuals, and also some extra troubleshooting booklets (they say more or less the same, though, although cabling varies slightly from the general troubleshooting towards my installation)

I measure the connections, and it seems the ground connection didn't have too good contact. It has now:

I took all connections off, cleaned them with contact cleaner, and put them back on. While contact cleaner is good for just that - what should I do after I am done to prevent corrosion - cover all connections in grease? Contact cleaner sure makes contact, but also leaves it open for subsequent corrosion.

Using the MC-624 from port side, I got the starboard side up and running.

It's doing what it did before failing, however, and this has me concerned (increasing to above 31V DC charging in a 24V system). Also, i cannot find and over-voltage scenario in the troubleshooting sections.

The voltage goes up to about 2.5 V above the commanded voltage, so even when at stage S03 (or is it 503?), the voltage is above 31V DC on both alternator and on the main ship DC panel.

Yes, I have all DC and AC equipment switched off and yes, I also measured on the MC-624 itself: All three (alternator/MC-624/House Battery switch panel) say close to the same value, over 31V DC while the MC-624 is claiming to command only 28.7 (it varies slightly from test to test, obviously, depending on which stage the MC-624 is in it's program).

I measured the resistance between the MC-624 connection and the alternator, for both field and power (with engine and ignition off). Both are less than 0.5 ohm, so that should be OK?

Also with all systems off, when I measure the voltage on the alternator, the MC-624 power and compare to the ships battery indicator on the main ship DC panel, they all stay within 0.1 V DC. If the connection had been bad, there should have been a significant difference.

I made a video where the DC Voltmeter is connected to the alternator, while the engine has just been started not long ago. Unfortunately, we can only see the commanded voltage every time the display is cycling through that Bu and Cu:

https://www.youtube.com/watch?v=O17_YzOTrdM

As it goes up above 31V, I can't keep measuring to see what it does, as I am afraid to kill the (almost newly replaced) 4 house AGM batteries.

Both engines and their MC-624 are connected to the 24 house battery bank (as is solar panel controller, Viltron 24/3000/70 inverter-charger, a separate Vinctron Centaur charger (mostly disconnected though) and then of course the Genset (Panda Fisher). There is a CenterFielder to balance out the two MC-624s. No DuoCharge is installed (to charge back the 12V start batteries).

As far as I know, all of these charging sources are connected directly to the 24V house bank. I can't really see how they can all co-exist without some kind of controller of sorts, but that's how the boat is built. Maybe this is normal. The electric diagrams reflects this description (can upload if it helps)

So ... the conclusion is (for starboard engine) that the alternator simply needs servicing?

Thank you for all your feedback and help.

[DITB]

That would have been two times "Victron" in the previous post. I didn't catch that autocorrect changed it.

Can't edit the post any more it seems.

[DITB]

Great news!

Balmar replied - I just need to pay for shipping, and they will send me a new MC-624, even though it's out of warranty (from October 2010)

And yes, I will have both alternators serviced as well, as soon as I can't proceed further on my own.

[DITB]

I hope I didn't scare away everyone from this thread

More findings today:

Moved the working MC-624 back to port engine. Cleaned all contacts, and did some measurements. The alternator never gets a field other than about 2.2V, and I am using the troubleshooting from the book. The centerfielder gets a signal from ignition, but I don't see anything on the field. I tried to disconnect those centerfielder cables, as I am running one engine at a time anyway for testing - and no difference (no charging with the MC-624)

I can manually engage the alternator by making a proper field voltage - at that surely brings the alternator to life!

From 1,400 rpm, I can hear a slight drop in RPM (no need for magnetic sensing here), and the charging voltage jumps to ... 31+ V DC, just as on starboard engine!

"Balmar 6-series alternators" - I didn't find a specific reference to this, but am I right when I am guessing that 60, 621 and any other Balmar alternator of the format 6x or 6xx is a "6-series"?

If this is the case, them my 60-24-70-SR-IG alternators should have the "Smart Ready" internal regulator installed - which can be used as emergency back-up in case of external regulator failure. I couldn't find a "How to use the Smart Ready internal regulator" section, but rather indirect descriptions of what it can be used for. I do have one diagram, involving a "double throw switch". When I hook up the alternator this way, I get 31+ V DC ... which is quite a lot of voltage for a 24V battery system.

I know I can just call in the pros to come help me, but I thought there must be a way to figure out more of how this works. Yes I'm a novice in many areas, but I gotta start somewhere. The more I can learn myself about the systems on board, the better I feel prepared if something happens at sea.