locked Re: tb/AMEL 54 outhaul protector burn out Mid Atlantic/AYOG

Brent Cameron

LOL. Don’t know about the “wouldn’t know”. Most Dutch guys I’ve know have been  pretty smart. Stubborn but smart.   

Anyway, it is no surprise that the TOP pops before the breaker. The breaker is designed to pop on relatively instantaneous short circuits of very high currents while the TOP won’t trip with a high starting current but is designed to trip when the motor gets overloaded (or the bearings seize, there is a difference between phases of the wiring, lower than expected supply voltage, etc). 

You can protect the motor using a beaker with a significantly smaller capacity than the wire can support but this is suboptimal. Those TOP devices SHOULD be set to trip at at lower amperages than would melt the wires.  I’m guessing that Amel had issues with people operating those particular motors in conditions where they were burning out or tripping the breakers too often and installed these to address that.  A lot of smaller AC Motors have them built in but I’m less familiar with DC motors as my experience in this area is with very large AC motors of hundreds and thousands of HP. 

There are some breakers that combine both functions but ideally you want a breaker that only pops to save the wires and won’t trip at a momentary high starting current with a TOP providing protection to the motor itself. This widens the range at which the circuit can operate without inoportuna trips.  These particular TOPs  seem to be failing in a fairly dangerous way that might not even be tied to any particular overload. That seems a bit scary to say the leaf. They aren’t normally fail unsafe like this. They are a good item to have but I’d be looking at these pretty closely. 

On May 17, 2022, 11:16 PM -0400, Nick Newington via groups.io <ngtnewington@...>, wrote:

On my 54 hull number 019 there are no Thermal Overload Protectors installed. We only have the four breakers:

Mainsail mast
Boom outhaul

I occasionally pop the outhaul and mast breakers. They pop pretty easily. I have felt the motors when they pop and they are not hot.

The breaker is doing its job.

I guess the earlier 54’s did not have TOPs installed.

I also guess that it is the TOP itself that is a danger, as suggested a component within it…

I question the need for the TOP at all; the Windlasses and Thruster only have breakers and the Bowthruster has a 425A fuse but a thermal overload shutdown inbuilt…In my opinion the Bowthruster is a potential fire source but at sea it is turned off at least on passage it is. Ditto with the windlasses.

Furthermore I question the safety of having the TOP installed at all…

Yet Amel clearly decided to add them to later 54s. Maybe there was a problem with mast/boom motor burnouts…

If the mast/boom motors were to burn out at sea, not the end of the world. No fire on board, and an acceptable manual back up for sail handling.  

When the photo of the burned TOP hit my inbox I immediately checked behind the double wall in the port cabin. I breathed a sigh of relief that none had been installed…

S/Y Amelia
AML54-019 Fethiye Turkey

On 18 May 2022, at 04:17, Teun BAAS <teun@...> wrote:



Brian next to me on SV LOLA (SUPER MARAMU 2000) says exactly the same about me: wooden shoes, wooden head – wouldn’t know 😊. In addition he proclaims to everybody on the dock that he tried to drown me but failed as my wooden shoes make me float.


There is a circuit breaker about 50 cm before that particular TOP which would be in between the motor and the battery bank.


We just can not understand why the breaker doesn’t trip but the TOP about 50 cm down the line burns out and I have to agree with Arno that a component inside the TOP is the problem.


Best Regards Teun

SV AMELIT  A54  #128



May 18, 2022 11:16:04


You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT


From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Brent Cameron via groups.io
Sent: Wednesday, May 18, 2022 11:04
To: Danny and Yvonne SIMMS <simms@...>; main@AmelYachtOwners.groups.io; main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] tb/AMEL 54 outhaul protector burn out Mid Atlantic/AYOG


Thanks Tuen, I’m quite aware of the Dutch tendencies as one of my best friends and my brother in law both are stereotypical examples. I always tease them with “wooden shoes, wooden head, wouldn’t listen”.  I’m Canadian and we have our own issues so let me apologize for that in advance.  LOL. 

Let me also apologize for not realizing that picture was your boat. The posts were coming in to my emails in weird orders so I got a bit confused.  I also had thought that it was a circuit breaker that failed and not a TOP. The purpose of the Thermal Overload Protector is actually to protect the motor - especially against excess heat from too much work being demanded of it.  This is in contrast to the circuit breaker or fuse which is intended to protect the downstream wires.  Replacing a TOP with a fuse or C/B causes you to lost that functionality so he will have to be careful to not overload the motor as it is running without that protection now but as you say, I’m sure he already does that. 

It really does seem like it’s a problem with the TOP device and a sample size of three boats in a short period of time seems to indicate an issue.  I don’t believe it has anything to do with the Lithium’s either as AGM’s are more than capable of supplying enough current to do that kind of damage. 

I’m glad he’s safe and none of your three boats were seriously damaged or lost to the damage.  On Amelit, I’d reinstall a TOP and replace that 100A fuse as you need both wire and motor protection and that fuse is very likely providing neither (assuming it is oversized for the wire) if there isn’t also a circuit breaker for that circuit closer to the battery bank (in which case perhaps the 100A fuse is meant to serve as a limp home mode knowing you’ve lost the TOP.   Anyway, without knowing the circuit it’s dangerous for me to speculate further.  


On May 17, 2022, 7:43 PM -0400, Teun BAAS <teun@...>, wrote:

Danny, Brent et al,


Let me address a couple of possibly misunderstandings:


  1. Brent: the pictures I have seen so far are Courtney’s and the other one is from my boat AMELIT (#128). We have NO pictures of LUNA (#122) Arno’s boat. Clearly on my boat there was also a burn out situation with the left black box (this is a thermal overload protector - TOP) before I got her. I discovered this when my left TOP failed in 2018/2019 in NEW CALEDONIA. I didn’t pay attention to the Amps but informed AMEL I needed a new TOP and they sent the current 75A unit which did NOT work on arrival and since I needed to leave NEW CAL we put back the AMEL supplied purple 100A fuse. Although I do agree & am aware on the Amps & wiring requirements I reasoned that this was an AMEL designed & supplied redundancy/limp home solution so safe to use.


  1. I am now personally aware of 3 AMEL 54 which had the same left TOP unit burn out  at EXACTLY the same location: the top left corner. Pls realize: 1) there are/is NO connector on that side of the TOP; the connectors are @ the bottom – totally on the opposite side of the TOP. 2) on my boat absolutely NO corrosion on those connectors at all. So no bad connection or corroded connection issues at all. It is clearly a component inside that black box/TOP.


  1. Arno is typical Dutch (difficult & stubborn) extremely anal about maintaining LUNA to the highest standards so I am convinced absolutely no corroding on his boat. I asked him if he excessively used the boom and/or used in strong winds and/or under heavy loads. He replied: not at all – just regular usage.


  1. Arno seems to think it is a MOSFET transistor shorting out; I have no clue what a MOSFET is but Arno is very familiar with electricity etc. etc.


  1. We also discussed if this could be related to/caused by the LITHIUM (he recently installed) creating a voltage spike; he doesn’t think so but we discussed this briefly as I am, jointly with the AMEL SUPER MARAMU 2000 next to me, working/deciding on a joint installation of a complete VICTRON LITHIUM systems.


  1. Pls bear in mind that in addition to the TOPS we are have 4 breakers outside right next to the TOP compartment: Head sail; Boom; Staysail and Mast. Only the Boom and the Mast have the TOP protectors inside the double wall.



Finally – on all 3 A54 I am now aware the burn out was on the left TOP and then on each unit on the left top side. Clearly there is an issue with a component at that location inside the TOP/back box.


Best Regards Teun

SV AMELIT  A54  #128



May 18, 2022 09:43:10


You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT



From: Danny and Yvonne SIMMS <simms@...>
Sent: Wednesday, May 18, 2022 03:44
To: main@AmelYachtOwners.groups.io; Teun BAAS <teun@...>
Subject: Re: [AmelYachtOwners] tb/AMEL 54 outhaul protector burn out Mid Atlantic/AYOG


Thanks Teun, what is the amperage of the fuse that is in situ. I remain of the opinion that alternative (Particularly higher) amperage fuses should not be provided for the same circuit. There is a load/wire size and the fuse should be appropriate ie it will trip when the design load is exceeded.

If I overload either the main outhaul or furler motors on Ocean Pearl, my breakers trip, and so they should That scary photo of what could easily have developed into a boat loss fire demands proper investigation. 

Kind Regards


On 17/05/2022 20:21 Teun BAAS <teun@...> wrote:





If you look at the picture I sent you can see the purple (100A) Jumbo fuse zip tied to the bundle of wires. This is ONLY one way to utilize that fuse in that compartment.


Besides my A54 (hull 128) the same set up on Arno’s boat (hull 122) and I know of another A54 with identical set up. 

Brgds Teun




On May 17, 2022, at 14:35, Danny and Yvonne SIMMS via groups.io <simms@...> wrote:

Hi all again,

I cannot believe the different amperage breakers provided by Amel would have been intended for the same circuits. Olivier can you advise.

Kind regards


SM 299

Ocean Pearl

On 17/05/2022 08:13 Danny and Yvonne SIMMS <simms@...> wrote:





Subject: Re: [AmelYachtOwners] tb/AMEL 54 outhaul protector burn out Mid Atlantic/AYOG



Hi Teun, Breakers, as Brent has pointed out are there to protect the down stream wire. They trip from either a short circuit or overload downstream from the breaker. The response should NEVER BE INSTALLING A BIGGER BREAKER. FIND THE CAUSE AND FIX IT.  The smoke and blackening is another issue, it is not the response of a breaker to overload. It is highly likely caused by poor connection of the wires in or out of the unit. I had a near house fire from a control unit for underfloor heating smoldering and then as I searched the source of the smell, seeing it break in to flames. A specialist house fire investigator said electrical unit connection fire was a common cause of catastrophic house fires. And the cause of the unit connections burning was poor wire connections in the units developing over time. On a boat corrosion is the enemy of good electrical connection. It can occur anywhere through salt laden air and more so in areas accessible to salt water trickles or splashes. So folks, the overheating and smoking of these breakers is the symptom, not the illness. Find the cause, and please dont respond with ever bigger breakers

Kind Regards


SM 299

Ocean Pearl   

On 16/05/2022 23:00 Brent Cameron via groups.io <brentcameron61@...> wrote:



Tuen, as was pointed out (correctly) here a few weeks ago, fuses and circuit breakers are NOT designed to protect the load device but protect the wire going to it. I don’t know the size of the wire that this fuse is protecting (it would be the wire between the fuse and the load) but if you can measure the diameter and ensure it’s copper, a quick look up will give you the amps that wire can safely carry at the specified voltage.   I strongly believe that a 100A breaker would be too big if the original was 40-55A. Installing this could have the same impact as no fuse or circuit breaker at all and could result in the wire melting and a fire.   

A few decades ago there was an Air Canada pilot who noticed that the toilet pump in the rear lavatory  on his jet was popping the circuit breaker so kept resetting it so the passengers could use it and this resulted in an inflight fire, emergency landing and significant number of deaths.   

The long and the short of it is that this breaker very likely tripped because there was something wrong with the circuit and not because it was underside for the wires. The fact that it emitted a lot of smoke tends to confirm that. 

I’d figure out the size/gauge of the smallest wire between the breaker and the load, do a look up to see what current it can safely carry and ensure that it is more than 100A before I’d even dream of installing that as it wouldn’t be much better than bypassing it altogether if it isn’t (other than the ability to shut the circuit down manually).   

I would also be VERY careful even if installing a new one of the same size to figure out why the original failed rather than tripped. Could it be a bad connection at the breaker or at the load? An internal short in the load?    Is there some issue with the load causing it to draw way more current than normal?  To measure the current draw, you need a clamp on type Ammeter capable of measuring DC Amps of that size). Most of the cheap knock off meters can’t do that but good ones like Flukes can.     

Twin, please tell Arno NOT to install the 100A breaker until you or someone here can confirm it isn’t too big for the wires.  A fire at sea is all our worst nightmares.    


On May 16, 2022, 5:33 AM -0400, Teun BAAS <teun@...>, wrote:

A friend of mine (Arno) is currently with his A54 (#122) 1200 NM into his passage to the AZORES and texted me this afternoon that the main outhaul protector burned. This protector is behind a panel next to the breakers in the bulkhead of the Guest cabin. There are 2 black protectors: he informed me that he has a 55A and a 40A. At this point I don't know which one burned. He also confirmed he had the Purple spare 100A fuse which he is going to plug in in the morning (the burn out happened during the night). 
He also told me that there was a massive amount of smoke & stench and feels that somebody sleeping in that cabin could have died from smoke inhalation.

BTW - one of the reasons I installed 3 smoke & carbon etc. detectors in the boat 2 weeks ago. 

On my A54 (#128) there is a heavy black spot of charred wood at the top left corner of the protector closest to the cabinet (the left one) - this was there from the original owner. I now remember that in 2018/2019 I had a malfunctioning protector and ordered from AMEL a new protector and they sent a 75A black box. I now also remember that on installation of this new 75A protector (in NEW CALEDONIA) it didn't work and we used the Purple 100A fuse between the white and the orange wire and it worked fine.

Until today, when I checked for Arno, I completely forgot about this happening and noticed today that I carry in that compartment 3 spare Purple 100 A  fuses. The other (right hand side) black box protector on my boat is 55Amp and appears to be original. 

This would mean that AMEL changed the 45A protector into a 75A protector????

Arno remembers a discussion on the forum on this A54 protector burn out but has no access to the internet/Forum. Can anybody actually familiar with this issue tell us their experience; what caused it and what to do other than using the 100A fuse.

Discussing with an AMEL 53 couple laying right next to me here in the Marina they remarked that a 100A fuse is a massive, massive fuse - what are the potential consequences using this (AMEL installed spare) fuse?

Thanks for the help


Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada

Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada

Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada

Join main@AmelYachtOwners.groups.io to automatically receive all group messages.