Advansea S400 Sounder Problem

[Bill McIndoe]

Sounder Problems
Hi,
I am having a problem with my Advansea Multi S400 Depth Sounder and seek help from the Cruising Log Forum members.
About two years ago I replaced my Navman sounder instrument because the figures were not illuminating properly and the interior of the face was fogging. I replaced it with a Advansea Multi S400 sounder unit which was designed as a specific replacement. The transducer was not replaced because it had been tested in place, seemed OK and it was a big job to change.

For some time I have been having a problem with the Advansea Multi S400.
When the engine is stopped and the S400 is powered only from the well charged bank of 4 house batteries it records the depth accurately.
When the engine is running at idle it records the depth accurately.
When I increase to say 1200 revs and the charge voltage from my Bosch 120A
alternator reaches about 13.8 volts the depth figures on the screen flicker and then disappear.
This occurs when the water depth is below 5m.

When the water deepens to say 10m the depth comes back on the screen with the engine still at 1200revs or higher.

On first starting the engine the BEP ER3 Automatic three stage controller will bring up the charge rate to 14.7v and after about 10 minutes it will drop back to 14.2v as it should according to the BEP ER3 manual but there is no depth showing on the screen.

We connected and tried it with a another transducer with the same result.

According to the Advansea Multi S400 User Manual page 6 the Sounder should be able to operate on a voltage from 9v to 16.5v, but at 13.8v, well within its operating range, the unit fails

Could any member please help me in this problem.
With our draft of 1.7m and we are doing adventuresome gunk-holing around the minor channels in the Otago Harbour it is scary when the water gets thin and the sounder goes blank.
Yes the system is more complex than I have described here but my electrician friend Graham and I have tried to sort out where the possible problem is without bringing in unnecessary complications. But we can tell you about the whole system if it would help.
Best Regards,
Bill McIndoe
Yacht Avanti (Cav39), Careys Bay,
Port Chalmers, Dunedin, New Zealand.

[redbopeep]

Hi there,

We don't have specific helpful advice for your case, sorry to say. I'm just writing to say you're experiencing something rather similar to our problems with Airmar DST transducer attached to a CruzPro MaxVu display. Hubby believes it it related to engine start-up in our case and I can't get further into it because that's all I know. He's abed and I'm standing anchor watch so I'm on the computer and just saw your post. I'll ask him to read and reply to your post during his watch if we still have internet access in a few hours.

Fair winds,

[Bill McIndoe]

Thank you for your reply.
I hope it is not blowing too hard!
We are planning to install a gizmo that adjusts the supply voltage to the Display Unit to say 13v. Then no matter that the 120amp alternator produces 14.2v for charging the batteries only 13v gets to the Sounder.
Regards
Bill McIndoe

[redbopeep]

Many people do like putting something to isolate the instrument. In our case we believe the instrument display is the problem (because it locks up on everything being displayed including that from the DST tranducer) rather than just the transducer. Hubby says that, in theory, the battery bank should act as a huge capacitor and should dampen voltage spikes coming from your alternator but in practice this doesn't seem to occur.

We have considered switching our engine charging to just the engine start battery and seeing if everything suddenly gets nice for us. Haven't done that yet since we like having the engine charge everything. Our DST isn't as sensitive to RPM and all as yours--what happens with us is when we start the engine, there's a spike and the display of the DST goes blank and stays that way until we literally shut off the power to the display (breaker or unplug display) and recycle it.

Our Interphase FLS is a back-up in terms of providing depth information. It is incredibly sensitive to engine RPM and a host of other things such that it usually doesn't provide depth (or FLS) information as needed. Fortunately, for whatever reason, when the CruzPro MaxVu display has decided to take a break, often the FLS is actually working correctly.

Let us know how the isolation goes because that's our next thing to do for the FLS itself. The battery charging switch should (in theory) work for our problem but it is certainly temporary.

The winds were OK, windier today so hubby is outside sanding varnish (so nice, the dust just flies away) prep for me.

[Bill McIndoe]

Hi Redbopeep,

We have solved the Adversea S400 Multi sounder problem. Because this discovery might help you improve your sounder I have described our journey from despair to success in detail. Your comments about your own system were most helpful and set me on the correct thinking pattern which eventually led to success. I thank you.
Background:
In Avanti there are two alternators. A 70Amp alternator fitted to the 50hp Yanmar is dedicated to charging the starter battery only. The 120Amp Bosch alternator, controlled by a BEP ER3 automatic 3 stage controller, charges the 4 house batteries (280AH). The two banks of batteries can be cross-connected by closing the isolator switch.
The Problem:
The Adversea S400 Multi sounder:
Would operate when the engine was stopped (12.5v), and also when it was idling (12.7v). When revs were increased to 1200rpm, the 120Amp alternator cut in and the voltage increased to 14.7v, the screen went blank.
Although the sounder should operate between 9v and 16.5v it was only operating at under 12.7v.
We considered that because of a fault, the display unit could not accept the higher voltage and if we reduced the voltage at the display unit to 12v it would solve the problem.
I purchased a $NZ45 Voltage Controller, that would reduce the voltage from up to 24v down to 12v, which we wired into the circuit. This gave 12v at the display screen.
We were disappointed that it made no difference to the display still going blank!!
I disconnected the wires supplying power to the field windings of the 120Amp alternator so it did not generate (but was still being driven round) and then closed the isolating switch between the battery banks so the 70Amp alternator would be the only one charging into both battery banks.

When I revved up the engine the sounder display again went blank. It seemed the only possible explanation was that although the 120Amp alternator was disconnected electrically and not producing power, because it was still being driven round by the belt, there was some extraneous current still being produced. Perturbation perhaps?

I removed the belt from the 120Amp alternator, started the engine and revved it up. The 70Amp alternator was then charging both banks of batteries at 14.5v and the 120Amp alternator was stationary.
The sounder then worked perfectly.
There is nothing wrong with the Advansea S400 Multi.

The problem was caused by a signal coming from the 120 Amp alternator. A blown diode perhaps or what? Maybe perturbation caused by electrical current of peaks and lows that the sounder display misread?
What to do?
We intend to put the belt back and test the output on a oscilloscope to find where it is faulty. Maybe the diodes can be replaced. Maybe a new alternator is a better idea.
Either that or an automatic selective charging switch so the charge from the one alternator will select whichever battery bank needs charging.
Because the 70Amp alternator is capable of charging the 350APH of the two battery banks, and the sounder is now operating. Next week I will think about how to have both alternators operating.
I am back on the water exploring the gunk-holes of the Otago Harbour where the water sometimes gets thin. There is a spot of nice late winter sunshine promised for the weekend. A day sail and a picnic lunch out on the Harbour sounds wonderful.

Bill McIndoe
Careys Bay, NZ