All DC Breakers tripping

[Keeping Up]

Is there any way that the brief voltage spike that occurs when a large load is switched off, could contain enough energy to trip the breakers? Its high-frequency leading edge just might then spread to all the circuits. For example, I have a 240v fridge, and I found that often when the motor cut out, the sudden cessation of current taken by the inverter would cause my 12v LCD detector to trip and sound an alarm as well as some other random 12v equipment misbehaviour. This led me to many sleepless nights before I tracked it down (and cured it with a big capacitor across the 12v supply)

 

Edited June 14, 2020 by Keeping Up

[Sir Nibble]

Usually each breaker will pick up a supply from a bus bar and deliver it to a consumer. If this is the whole truth then all the breakers tripping simultaneously is impossible. Since they do all trip simultaneously the first statement cannot be the whole truth. I don't have a particular theory in mind but I would like to know A/ are these single pole breakers carrying supply only, or double pole devices also carrying the return? B/ is each breaker connected to a complete circuit? That is to say, if one supplies only the horn button, then until the button is pressed there is no circuit. So are all the breakers on load?

[Jaston10078]

Here's a diagram of how I understand our boat to be wired... I've not included battery isolators and engine panel 

 

Wiring diagram

[Jaston10078]

1 hour ago, Sir Nibble said:

Usually each breaker will pick up a supply from a bus bar and deliver it to a consumer. If this is the whole truth then all the breakers tripping simultaneously is impossible. Since they do all trip simultaneously the first statement cannot be the whole truth. I don't have a particular theory in mind but I would like to know A/ are these single pole breakers carrying supply only, or double pole devices also carrying the return? B/ is each breaker connected to a complete circuit? That is to say, if one supplies only the horn button, then until the button is pressed there is no circuit. So are all the breakers on load?

Hi Sir Nibble, I'm assuming single pole as there is a separate negative bus bar for all negatives... I'm not sure what you mean about the breakers being on load.

Edited June 14, 2020 by Jaston10078

[Sir Nibble]

3 minutes ago, Jaston10078 said:

Hi Sir Nibble, I'm assuming single pole as there is a separate negative bus bar for all negatives... I'm not sure what you mean about the breakers being on load.

What I mean is if the only connection from a breaker is to a switch that's turned off, then there may as well be no connection at all. It's simply not possible for any current at all to be flowing through the breaker without an uninterrupted path to negative.

[Jaston10078]

Just now, Sir Nibble said:

What I mean is if the only connection from a breaker is to a switch that's turned off, then there may as well be no connection at all. It's simply not possible for any current at all to be flowing through the breaker without an uninterrupted path to negative.

Well, this is what had me thinking... On the load side of the breaker is a positive feed to the indicator led on each breaker. The indicator lights up to say that the circuit is working and goes out when the breaker trips so there is current flowing through the breaker even if the appliance is off. 

[WotEver]

30 minutes ago, Jaston10078 said:

Here's a diagram of how I understand our boat to be wired... I've not included battery isolators and engine panel 

Dunno why it’s pink but...

8 minutes ago, Jaston10078 said:

Well, this is what had me thinking... On the load side of the breaker is a positive feed to the indicator led on each breaker. The indicator lights up to say that the circuit is working and goes out when the breaker trips so there is current flowing through the breaker even if the appliance is off. 

But you’ve disconnected the negative returns for those LEDs, so there isn’t a current flowing. 
 

Insulate the ends of each of those disconnected wires and see if it stops happening. 

[Tracy D'arth]

So, the leds each get their negative returns through the appliances connected to that breaker. 

Still doesn't explain the tripping though.

Edited June 14, 2020 by Tracy D'arth

[Jaston10078]

9 minutes ago, WotEver said:

Dunno why it’s pink but...

But you’ve disconnected the negative returns for those LEDs, so there isn’t a current flowing. 
 

Insulate the ends of each of those disconnected wires and see if it stops happening. 

Those cables are black but are not negative returns, they are positive feeds to the LEDs. They connect to the positive load side of the breaker on the same lug as the cable to appliance. 

 

3 are disconnected in the photo. These 3 breakers are not in use. 

Edited June 14, 2020 by Jaston10078

[WotEver]

1 minute ago, Jaston10078 said:

Those cables are black but are not negative returns, they are positive feeds to the LEDs 

All the more reason to tape them up. 

6 minutes ago, Tracy D'arth said:

So, the leds each get their negative returns through the appliances connected to that breaker

?????

 

How would that work? LEDs across the breaker would indicate that the breaker was off. As OP states they indicate when the breaker is ON they must have a permanent -ve connection with the +ve fed down those black wires. 

[Jaston10078]

1 minute ago, WotEver said:

All the more reason to tape them up. 

Sorry... They take positive from the load side of the breaker and deliver it to the LEDs. My multimeter reads 0 voltage between the terminals at the end of the disconnected cables and negative. I will tape them up anyway. 

[WotEver]

47 minutes ago, Jaston10078 said:

Here's a diagram of how I understand our boat to be wired...

There should be a fuse at the battery end of the feed to the breaker panel. 

[Jaston10078]

1 minute ago, WotEver said:

There should be a fuse at the battery end of the feed to the breaker panel. 

Yeah, you're right... Not noticed that 

[Tracy D'arth]

8 minutes ago, WotEver said:

All the more reason to tape them up. 

?????

 

How would that work? LEDs across the breaker would indicate that the breaker was off. As OP states they indicate when the breaker is ON they must have a permanent -ve connection with the +ve fed down those black wires. 

I'm in error. If the led lights to show the breaker is on then there must be a negative common connection for all the leds. You are correct.

The common way these panels are wired is with the leds across the breaker, then they light up when the breaker trips. Either way they are idiot lights, I would dis them all.

[David Mack]

29 minutes ago, Tracy D'arth said:

 

The common way these panels are wired is with the leds across the breaker, then they light up when the breaker trips.

But only if the load to which the breaker is connected is switched on. 

[Tony Brooks]

As I said earlier an illuminate for on indicator usually has a an extra negative on the breaker.  Tracy is talking about an illuminate when broke, and the illumination would go out if the load was turned off.

[Jaston10078]

6 hours ago, Keeping Up said:

Is there any way that the brief voltage spike that occurs when a large load is switched off, could contain enough energy to trip the breakers? Its high-frequency leading edge just might then spread to all the circuits. For example, I have a 240v fridge, and I found that often when the motor cut out, the sudden cessation of current taken by the inverter would cause my 12v LCD detector to trip and sound an alarm as well as some other random 12v equipment misbehaviour. This led me to many sleepless nights before I tracked it down (and cured it with a big capacitor across the 12v supply)

 

I have a feeling you might be on to something here... 

[Keeping Up]

To correct the smell-chucking error that I didn't notice before, it was my 12v LPG detector that kept being triggered (hence the sleepless nights).

[Jaston10078]

27 minutes ago, Keeping Up said:

To correct the smell-chucking error that I didn't notice before, it was my 12v LPG detector that kept being triggered (hence the sleepless nights).

Ah, yes that would be concerning ?

[Jaston10078]

On 14/06/2020 at 12:21, Tony Brooks said:

Long, long shot. Is there any possibility this coincides with sharp movements or heavy vibration?

Sorry for the late reply, Tony. 

 

No sharp movements or heavy vibration... Though to test this, I gave the wooden panel upon which the breakers are mounted a moderate beating with a rubber mallet... The breakers were unaffected. My wife thinks I'm going mad. 

No breakers tripping all of yesterday... Charged the batteries with the generator with no apparent issue. Fridge doing its thing quite happily... Intermittent faults... Infuriating 

 

Edited June 15, 2020 by Jaston10078

[Tony Brooks]

28 minutes ago, Jaston10078 said:

Sorry for the late reply, Tony. 

 

No sharp movements or heavy vibration... Though to test this, I gave the wooden panel upon which the breakers are mounted a moderate beating with a rubber mallet... The breakers were unaffected. My wife thinks I'm going mad. 

No breakers tripping all of yesterday... Charged the batteries with the generator with no apparent issue. Fridge doing its thing quite happily... Intermittent faults... Infuriating 

 

 

Just about the worst sort of fault - I bet if you got someone to look at the boat it would refuse to show any faults at all.

[Jaston10078]

On 15/06/2020 at 12:58, Tony Brooks said:

 

Just about the worst sort of fault - I bet if you got someone to look at the boat it would refuse to show any faults at all.

Just an update. Since posting my original post the breakers have not tripped. With electrical tape I did Insulate the ends of the loose led indicator cables for the unused breakers. 

[Tony Brooks]

7 minutes ago, Jaston10078 said:

Just an update. Since posting my original post the breakers have not tripped. With electrical tape I did Insulate the ends of the loose led indicator cables for the unused breakers. 

Pleased it seems to be sorted for now and thanks for the feedback but I still cant see how that helps.

[WotEver]

46 minutes ago, Tony Brooks said:

Pleased it seems to be sorted for now and thanks for the feedback but I still cant see how that helps.

Me neither but seeing wires with uninsulated ring terminals flapping about bothered me.