12v motor causing noise in 240v system

[Paul202]

Hi - On our small vessel we have a 12v failry powerful motor to run the autopilot, where the power is supplied by the boat's battery bank. On an 'independant' system we have 240v that is supplied via an inverter, but the power originates from the same battery bank as the 12v system. The problem is that we have a laptop to run a piece of scientific equiptment, and when the laptop is plugged in to the 240v, it picks up interference whenever the 12v autopilot motor is actuated. The laptop only has to be plugged in - the socket can be switched on or off and the interference is picked up by the laptop. There is no interference on the laptop when not plugged in. So some kind of noise is crossing over to the 240v wiring i guess.

We have tried a couple things so far; adding more ferrites in various places, as well as using a voltage cleaner (a bit like a UPS) between the 240 socket and laptop but the interference still gets through.

I've been looking at things like an IEC in-line filter that I can just plug in to the 240 and laptop cord, but these seem to only filter noise generated from mains power. I'm not an electrician so i'm a bit unclear on what the solution might be, as i'm not actually sure what kind of noise it is that's being generated. Any advices welcome. Thanks.

 

[marconi]

Whereabouts on the FI?

Please send me some pictures of the problem as seen on the laptop, the complete installation and the battery configuration - more than one?- and the autopilot motor. What type and amphour are the batteries? Details of inverter.

 

[Paul202]

Whereabouts on the FI?

Please send me some pictures of the problem as seen on the laptop, the complete installation and the battery configuration - more than one?- and the autopilot motor. What type and amphour are the batteries? Details of inverter.

Hi Marconi - thanks for replying. I'll gather some more details for you asap. For now, here is the laptop screen. the instrument is a side scan sonar and what you're looking at is the waterfall sounder trace. The interference lines are the horizontal spikes at the top of the screen. Those spikes correspond to when the 12v autopilot motor is engaged. when the laptop is not plugged into to the 240v, there are no spikes. I've also attached an image of the laptop plugged in for completeness. More details soon. Thanks. Oh and we're based in Stanley. Do you know the falklands?

 

[Paul202]

Whereabouts on the FI?

Please send me some pictures of the problem as seen on the laptop, the complete installation and the battery configuration - more than one?- and the autopilot motor. What type and amphour are the batteries? Details of inverter.

Hi again - more photos attached here with detail. Hope this is all clear. Happy to send any more detail. Thanks!

01. 4 x Hankoom 104 amp hrs house batteries.
02. House battery hook ups.
03. Primary inverter - Cotek. This is the normal 240 supply that runs the laptop and other appliances.

04. Mastervolt inverter. This was installed by previous owner. It's meant to be the 'clean' power source for running science gear but it's actually worse in terms of the interference problem. In my earlier image of the laptop you can see the red sockets - that's the Mastervolt but we don't use this.

05. Engines. The vessel is twin engine. Each engine has its own startup battery. The start batteries and house batteries are linked via a splitter. It's designed such that the start batteries are not accidentally drained if the house batteries are used eg kettles, microwave, etc.

06. Splitter
07. Raymarine Autopilot control
08. Autopilot 12v motor driving hydraulic control. Also see the big ferrite wired in.
09. Splitter wiring diagram
10. Antares Cotek detail - ours is 200w
11. Mastervolt detail. This functions but we rarely use this system.
12. Inverter control panels.

 

[marconi]

Just got home after visiting my wife. Glancing at your last post there is a lot there for me to study - thank you.

I am busy running a church quiz tomorrow night with a meal so it will not be until Sunday onwards that I start responding.

In 1986 I spent 4 months down South keeping the islands safe mainly midway between the FI and Argentina.

 

[Paul202]

Just got home after visiting my wife. Glancing at your last post there is a lot there for me to study - thank you.

I am busy running a church quiz tomorrow night with a meal so it will not be Sunday onwards that I start responding.

In 1986 I spent 4 months down South keeping the islands safe mainly midway between the FI and Argentina.

Hi there - all understood. Nice to know you know the Falklands. Our boat is the RV Jack Sollis, named after a local mariner who was a bit of a legend and played a big part in looking after folk during the conflict.

Looking forward to reading your diagnosis! Thanks very much for your time, and have a good weekend!

 

[marconi]

Starting work on your problem. Please would you describe the layout, axes and imagery in IMG 7788. What does it look like when the motor is not running?

In the 09 Splitter image what are the Ah ratings of each battery? Are they Advanced Gel Matrix types?

Is the red black 12V high current cabling all 70mm2? Images 01, 02 and 06. How long is the cable run between the batteries in 01 and the busbars in 02?

Is the dc system all 12V? Thus inverters are 12V dc powered?

I can see two inverters. What do they each do? What is the power supplied by each when you have the interference?

I can see 4 batteries in image 01 but the diagram in 09 only shows 3. Could you clarify please.

Have you had the interference problem since the installation was installed?

Has the problem been getting worse over time?

Forgive me as I have not yet read and delved further into all you have posted.

 

[Paul202]

Starting work on your problem. Please would you describe the layout, axes and imagery in IMG 7788. What does it look like when the motor is not running?

In the 09 Splitter image what are the Ah ratings of each battery? Are they Advanced Gel Matrix types?

Is the red black 12V high current cabling all 70mm2? Images 01, 02 and 06. How long is the cable run between the batteries in 01 and the busbars in 02?

Is the dc system all 12V? Thus inverters are 12V dc powered?

I can see two inverters. What do they each do? What is the power supplied by each when you have the interference?

I can see 4 batteries in image 01 but the diagram in 09 only shows 3. Could you clarify please.

Have you had the interference problem since the installation was installed?

Has the problem been getting worse over time?

Hi there - thanks for this. To answer your questions;

In the Img7788 - this is called a 'waterfall plot' from a side scan sonar mounted to the side of the vessel (or sometimes towed behind) to the vessel. The thick vertical middle line is the centre of the boat, and the right and left of the line are the port and starboard sounder channels. Across the top of the screen are distances in m from middle of the boat. The white dotted jagged line running vertically is the bottom tracking. As the boat travels forward, the plot 'falls' down the page. An example of interference caused by the autopilot motor making course corrections are the horizontal spikes in the left and right channels at top half of the screen, and the bottom half of the screen is clean scans while the vessel is heading in a straight line.

Image 09 Splitter - batteries are standard automotive batteries - 104 amp hrs, sealed gel.

12V red cabling is 35mm2. The cable runs between the batteries and busbar is about 2m max - they are adjacent to each other.

The DC system is all 12V. Inverters are powered but dc.

Inverters - the Antares Cotek runs normal house appliances - kettle, microwave, laptops, etc. This is the one we use for the side-scan sonar. The Mastervolt, as we were told when we purchased the boat, is the source of 'clean' power - in image7785 you can see the red 240v sockets - that's the MasterVolt. We never use this. We had hoped this system would solve the interference problem, but in fact it makes it much worse, so we don't use that system for anything at the moment.

There are 4 batteries for 12V system as in the photo. Sorry, I should have made that clear - the diagram is just as example from the manual.

We've had the interference from when we bought the boat in 2020. We've had a big tidy-up of all the battery and wiring configuration and made it safer. Interference has been the same - no better or worse.

Sounds like you're zeroing in a potential cause?

Thanks,
Paul

 

[marconi]

yes. I have hypotheses based on the resistance/impedance of :

the 12 V sources of emf ie the batteries,

the cabling design/selection

and topology of connections to the 12V loads.

 

[marconi]

Could you send me the model number of the ray marine controller and of the motor please.

 

[marconi]

Is there one engine with one 12V alternator?

 

[Paul202]

Could you send me the model number of the ray marine controller and of the motor please.

Hi - The Raymarine controller is a Smart Pilot ST8001. Motor / pump is type 1 - the only info is as it's shown in the picture. Cheers.

 

[marconi]

Hi - The Raymarine controller is a Smart Pilot ST8001. Motor / pump is type 1 - the only info is as it's shown in the picture. Cheers.

Grounding The Smartpilot - Raymarine SmartPilot ST6001 Commissioning Manual [Page 17] - https://www.manualslib.com/manual/314147/Raymarine-Smartpilot-St6001.html?page=17#manual

Greetings from London.

Please look at page 17 of the link. You will see some advice and a drawing of how the controller should be grounded. Could you take some pictures and describe to me how the installation in this regard is in your boat?

Does your boat have an 'earth/grounding' system? Is the boat metal or GRP? Is there a through hull earth electrode to connected to the sea water?

Is ferrite filter exactly as on page 16?

in image 08 12V autopilot motor one can see the motor, the ferrite filter and then black helical cable shrouding. Does the shrouding contain only the red and black for the motor or does it contain other cables too? If If there are other cables what are they for?

Further, the red and black to the motor from the ray marine controller must be twisted together all along their length like the picture below.

See also page 3 on minimum separation distances of raymarine cables from other equipment cables and page 16 on requirement for twisted motor cables in:

https://busse-yachtshop.de/pdf/raymarine-hydraulik-pumpe-install-en-ab2013.pdf

 

[marconi]

https://media.hudsonmarine.co.uk/uploads/Raymarine/Autopilots/Hydraulic Linear Drive Installation instructions.pdf

could you look at page 32 of link above and the diagram showing the hydraulic actuator. Do you have the wire numbered 9 going to the ray marine controller ground terminal? ( I have already asked I think for confirmation as to what and where the controller ground terminal is connected.)

Lots of questions to begin with to confirm the Raymarine equipment and rudder electro-hydraulic servo system has been installed in accordance with the manufacturer's guidance.

What is the power in Watts (or VA) of the laptop? It will be on the laptop or its power supply. And what voltage range? They are often 100V to 240V ac for example.

 

[Paul202]

https://media.hudsonmarine.co.uk/uploads/Raymarine/Autopilots/Hydraulic Linear Drive Installation instructions.pdf

could you look at page 32 of link above and the diagram showing the hydraulic actuator. Do you have the wire numbered 9 going to the ray marine controller ground terminal? ( I have already asked I think for confirmation as to what and where the controller ground terminal is connected.)

Hi - ok so....

Regarding the vessel ground system - the boat is GRP. We do not have a through the hull plate grounding system. Everything is grounded to the battery negative.

Pg 17 of Commissioning Manual. Our system is an S2G (see picture). According to the Commissioning Manual this should NOT be grounded? But it does have a positive and negative so it must be grounded?

Regarding the Hydraulic Linear Drive installation pg32 - there are no electronics on our system so no, there is no ground there. The one pictured seems to be a more modern version of ours.

Regarding the ferrite on pg 16 - no it seems we do not have this ferrite. I've attached a photo of the power leading into the S2 box.

Regarding other cables contained in the black helical cable shroud, I'll have to go back and check this. Similarly, I'll check the twisting.

Regarding minimum distances between cables etc, will have to check this as well but it's likely to be less than the minimum as the Raymarine VHF system is all integrated in the same area under the dash as well.


This has all been really helpful - thanks very much! I think you've identified several areas for us to check now. Our fear was that we would need to re-ground the whole boat which would be a major undertaking but I think you would suggest that this would be the best solution. With respect to a through the hull ground plate - can we take a line from the negative earth directly to the ground plate? Or do we need to re-ground all the boat's electronics to the new ground plate?

Is there a temporary solution that we can buy to remove/reduce the noise - for example something we can use in-line between the 240v socket and laptop that will removed this type of noise?

thanks,
Paul