electricity problem solving

[sailaboutvic]

Friends problem

( main power enter the boat and goes to a type of transformer to the victron inverter/ charger to some kind of switching device then to the RCD before entering the boat 230v electric)

1 Plug in the shore power with everything unplug in the boat and the RCD trip .
Victron charge is still powered .

2 doing the same without the shore power connect this time using victron inverter charger for 230v which also goes throught the same RCD and it doesn't trip ,
Plug in kettle , microwave etc and still it doesn't trip .


3 take a lead straight from the shore and connect to the RCD by passing the Victron inverter /charge still with every thing un plug and the RCD trips .

Any ideas ? Could it be the RCD ? And if so why doesn't it trip when 230v from the inverter is used .

Different shore power cables and different electric outlet used , no different the RCD still trip .

 

[Kurrawong_Kid]

Friends problem

( main power enter the boat and goes to a type of transformer to the victron inverter/ charger to some kind of switching device then to the RCD before entering the boat 230v electric)

1 Plug in the shore power with everything unplug in the boat and the RCD trip .
Victron charge is still powered .

2 doing the same without the shore power connect this time using victron inverter charger for 230v which also goes throught the same RCD and it doesn't trip ,
Plug in kettle , microwave etc and still it doesn't trip .


3 take a lead straight from the shore and connect to the RCD by passing the Victron inverter /charge still with every thing un plug and the RCD trips .

Any ideas ? Could it be the RCD ? And if so why doesn't it trip when 230v from the inverter is used .

Different shore power cables and different electric outlet used , no different the RCD still trip .

Is the shore power socket wired correctly? I.e. live and neutral “reversed”?

 

[sailaboutvic]

Is the shore power socket wired correctly? I.e. live and neutral “reversed”?

Been check plus its the same lead that's been used for some months ,
we also used another lead just to double check there wasn't a short .

 

[Billjratt]

"3 take a lead straight from the shore and connect to the RCD by passing the Victron inverter /charge still with every thing un plug and the RCD trips ."
In this scenario is the victron and everything else before the RCD disconnected? If so, there is indeed a problem within the boat in relation to shore ground. When you say everything unplugged, are you sure - is the immerser in the calorifier off for instance? You may need to isolate by tripping breakers in sequence or disconnecting circuits to isolate. is there a galvanic isolator fitted?

 

[HissyFit]

Been check plus its the same lead that's been used for some months ,
we also used another lead just to double check there wasn't a short .

But is the "other" lead wired the same as the first? It is wise to have an intermediate lead which swaps the live & neutral, for the reason that marina electrics have a reputation for being "variable" in quality/correct installation.

 

[sailaboutvic]

But is the "other" lead wired the same as the first? It is wise to have an intermediate lead which swaps the live & neutral, for the reason that marina electrics have a reputation for being "variable" in quality/correct installation.

Tested the marina polarity and its right , plus its been working fine on the same outlet for weeks.

 

[sailaboutvic]

"3 take a lead straight from the shore and connect to the RCD by passing the Victron inverter /charge still with every thing un plug and the RCD trips ."
In this scenario is the victron and everything else before the RCD disconnected? If so, there is indeed a problem within the boat in relation to shore ground. When you say everything unplugged, are you sure - is the immerser in the calorifier off for instance? You may need to isolate by tripping breakers in sequence or disconnecting circuits to isolate. is there a galvanic isolator fitted?

Everything from where the power came in to where it reaches the RCD ( victron charge/inverter switching box , transforer) are all disconnected .
Wires are removed from the rcd and only a lead from the shore power wired to the rcd .

100 % everything unplug .

What I can't understand is , why using the 230 inverter the rcd doesn't trip with all 230v equipment on , but as soon has the shore power on it trip , even it isolated every thing.

 

[PaulRainbow]

Everything from where the power came in to where it reaches the RCD ( victron charge/inverter switching box , transforer) are all disconnected .
Wires are removed from the rcd and only a lead from the shore power wired to the rcd .

100 % everything unplug .

What I can't understand is , why using the 230 inverter the rcd doesn't trip with all 230v equipment on , but as soon has the shore power on it trip , even it isolated every thing.

Most likely the inverter has separate circuits for stuff that can be run from the inverter and stuff that should only work when the shore power is on. The inverter circuit would typically exclude the immersion element, which would be the first thing i'd suspect.

Rather than unplug everything, manually trip all of the MCBs and turn the power on. If the RCD does not trip, switch the MCBs back on, one at a time, until you find which one trips the RCD.

Bet you a virtual pint it's the immersion element.

I appreciate that the Victron etc has only been bypassed for testing, but be aware that the transformer between shore power and the inverter is almost certainly an isolation transformer, without this, there is no protection from galvanic corrosion issues.

 

[PaulRainbow]

"3 take a lead straight from the shore and connect to the RCD by passing the Victron inverter /charge still with every thing un plug and the RCD trips ."
In this scenario is the victron and everything else before the RCD disconnected? If so, there is indeed a problem within the boat in relation to shore ground. When you say everything unplugged, are you sure - is the immerser in the calorifier off for instance? You may need to isolate by tripping breakers in sequence or disconnecting circuits to isolate. is there a galvanic isolator fitted?

Even if there was something connected prior to the RCD, that couldn't trip it.

Good points on the immersion element and tripping the breakers (i find it simpler/quicker to trip them all and switch them back on one at a time).

I'm almost certain that the transformer Vic mentioned is an isolation transformer, so it wouldn't have a GI, Even so, a faulty GI shouldn't trip an RCD.

 

[sailaboutvic]

Even if there was something connected prior to the RCD, that couldn't trip it.

Good points on the immersion element and tripping the breakers (i find it simpler/quicker to trip them all and switch them back on one at a time).

I'm almost certain that the transformer Vic mentioned is an isolation transformer, so it wouldn't have a GI, Even so, a faulty GI shouldn't trip an RCD.

Paul everything is unplug but even so if there was some thing we missed , surely once the inverter used the rcd would trip.
And it doesn't.
Problem just started last night , nothing been changed .

 

[Seastoke]

Even if there was something connected prior to the RCD, that couldn't trip it.

Good points on the immersion element and tripping the breakers (i find it simpler/quicker to trip them all and switch them back on one at a time).

I'm almost certain that the transformer Vic mentioned is an isolation transformer, so it wouldn't have a GI, Even so, a faulty GI shouldn't trip an RCD.

Remember Paul that the neutral at the element will still be connected so it may still trip , he needs to disconnect the element me thinks .

 

[Forty_Two]

The Victron invertor normally has a ground relay to ensure the RCD will trip when the inverter is active. I think there is an option to disable it. That could expain why the fault does not show up on the invertor. If there is indeed an isolation transformer that might br a reason to disable the ground relay.

 

[sailaboutvic]

Most likely the inverter has separate circuits for suff that can be run from the inverter and stuff that should only work when the mains on. The inverter circuit would typically exclude the immersion element, which would be the first thing i'd suspect.

Rather than unplug everything, manually trip all of the MCBs and turn the power on. If the RCD does not trip, switch the MCBs back on, one at a time, until you find which one trips the RCD.

Bet you a virtual pint it's the immersion element.

I appreciate that the Victron etc has only been bypassed for testing, but be aware that the transformer between shore power and the inverter is almost certainly an isolation transformer, without this, there is no protection from galvanic corrosion issues.

There only one trip after the RCD , if that's turn off the RCD doesn't trip as soon as it on the RCD trips .
But even so why when only using the inverter the RCD doesn't trip ,

 

[PaulRainbow]

Paul everything is unplug but even so if there was some thing we missed , surely once the inverter used the rcd would trip.
And it doesn't.
Problem just started last night , nothing been changed .

There are usually some devices that are not "plugged in". Immersion elements are usually connected directly, or connected via a switch spur.

Rather than unplug everything, manually trip all of the MCBs and turn the power on. If the RCD does not trip, switch the MCBs back on, one at a time, until you find which one trips the RCD.

 

[sailaboutvic]

The Victron invertor normally has a ground relay to ensure the RCD will trip when the inverter is active. I think there is an option to disable it. That could expain why the fault does not show up on the invertor. If there is indeed an isolation transformer that might br a reason to disable the ground relay.

Things are getting a bit lost here .
When the inverter us used the RCD don't trip

 

[sailaboutvic]

There are usually some devices that are not "plugged in". Immersion elements are usually connected directly, or connected via a switch spur.

Rather than unplug everything, manually trip all of the MCBs and turn the power on. If the RCD does not trip, switch the MCBs back on, one at a time, until you find which one trips the RCD.

I go over in the morning and make sure the immersion is not working . But as I said surly if the problem was the heater the RCD would trip when the inverter is used

 

[PaulRainbow]

Things are getting a bit lost here .
When the inverter us used the RCD don't trip

Forget the inverter for now, who's to say it's wired correctly?

You say the boat only has one MCB ? That's very unusual on anything other than a very minimal installation/small boat.

If there really is only one, it must has severel wires coming from it, or it supplies a busbar/DIN rail etc. He'll have to disconnect all of the wires and reconnect them one at a time until he finds which one trips the RCD.

 

[PaulRainbow]

I go over in the morning and make sure the immersion is not working . But as I said surly if the problem was the heater the RCD would trip when the inverter is used

Not necessarily, some of the Victron Multiplus models have two output circuits. One circuit supplies power all of the time, the other only supplies power if the shore power is on. Normal practice there is that any high current loads are connected to the circuit that only supplies power if the shore power is on, these would typically be the immersion heater and possibly other heating appliances etc.

 

[Forty_Two]

Things are getting a bit lost here .
When the inverter us used the RCD don't trip

Exactly, if the Invertor does not connect one leg of the output to ground, creating a neutral when operating, any Rcd after it will not trip when there is a ground fault as seems to be the case. Switch the invertor off or bypass it & the nuetral will appear again & allow the Rcd to trip.

 

[PaulRainbow]

Exactly, if the Invertor does not connect one leg of the output to ground, creating a neutral when operating, any Rcd after it will not trip when there is a ground fault as seems to be the case. Switch the invertor off or bypass it & the nuetral will appear again & allow the Rcd to trip.

Looks like you might be getting confused with centre tapped inverters, which the Victron is not.

It is, however, possible that the inverter has been incorrectly installed. Once the fault is found, the inverter installation must be checked. Once again though, i'd want to know how/where the immersion is connected