American electrical advice (shore power)

RobWales

RobWales

Well-Known Member
Joined
21 Sep 2006
Messages
1,963
Location
Gran Canaria
www.3ksengineering.com
Hi all,

I was hoping someone could enlighten me with regard the shore power electrical system aboard my Viking Yachts 42ft vessel.

My boat has two inlet sockets in the cockpit for shore power, on the 115v electrical control panel inside I have a selector switch for "Line1 Line1+2 or Generator" my main shore power lead has a single connection into the supply at the pontoon but then 1mtr prior to the boat connections side the lead splits with two plugs.

Every time I connect both (after being out for the day) it causes my supply box to trip and also the main trip on my supply meter at the box on the Marina wall....(a right pain)!!

I have recently discovered that by selecting only Line1 on my panel and only plugging one of the connections in at the cockpit I get no tripping and everything that is drawing power works perfectly.

My questions are thus......

Why are there two inputs?

Should I modify my supply lead by removing the split to two plugs and use just the one as I'm not happy with a live supply being hung up under my gunwhale....?

Many thanks in advance.
Rob.
 
Last edited:
does it also trip if the selection switch is in the 1+2 position, prior to plugging in the shore power ?

I also have two power inputs, and as soon as I plug in a second lead,
automatically my airco takes power from the second supply, and all the other 230V loads remain on the first.

afaik, your cable with two plugs doesn't make sense,
if the system can work as discribed above (with the manual selector) you would need a second power lead, in case you want split up the shore power over 2 (smaller) sockets instead of one big

first thing todo (if it is your boat and you will keep her) investigate, end get a detailed diagram of your electric panel / mains supply system .
 
American boats differ in their 220V shore power in that the difference is that the UK uses 220V / 50Hz on a single leg with a neutral or EU 220V 60Hz still single leg with a neutral, where as the US 220V 60Hz is two 110V hot legs plus a neutral.
 
If you can’t find a manual I would investigate with a multi meter the relationship between the two plugs that goes to power and the plug that goes into the boat.

I have tried joining two sockets together and it does not work. In Sardinia I took out the whole marina. Being British I denied it of course but given we were twice the size of every other boat ( they thought we were 12m when booking not 21) I really had nowhere to go !

Assume the voltage 240/120 is handled some how ?
 
Two on-board transformers, the previous owner tried to explain in broken English (bought boat in and live on in Gran Canaria) that the cause of the tripping was something to do with the phasing of the two units......lost me!
Just wondering why Two?
 
Transformers do take a large current for a very short time on startup.

When putting down floors in my house, I borrowed my brothers 110v gear and when plugging in the transformer it tripped the circuit breakers about 1 time in 3, and that was with nothing plugged into it.

Might be they need replacing or check if plugging it in on line 1 and then switching to 1 & 2 has the same effect. staggering the energising of the transformers may solve the problem.
 
RobWales said:
Two on-board transformers, the previous owner tried to explain in broken English (bought boat in and live on in Gran Canaria) that the cause of the tripping was something to do with the phasing of the two units......lost me!
Just wondering why Two?
Click to expand...

The very best and easiest way to fix this is to fit a Mastervolt Soft Start in the line as it comes into the boat, before the transformers. The best £240 you will spend on the boat.

I speak from experience on this.

Graham
 
RobWales said:
Hi all,

Should I modify my supply lead by removing the split to two plugs and use just the one as I'm not happy with a live supply being hung up under my gunwhale....?

Many thanks in advance.
Rob.
Click to expand...

Hi Rob, You really shouldn't have two plugs on the end of your shore power lead. First, as you say, it's a hazard to have a live plug hanging loose, but often, shore power suppliers are fed from different phases. So not surprised it causes problems.
 
GSL said:
The very best and easiest way to fix this is to fit a Mastervolt Soft Start in the line as it comes into the boat, before the transformers. The best £240 you will spend on the boat.

I speak from experience on this.

Graham
Click to expand...

This sounds like the right advice. At a guess the OP has two isolation step-up transformers, one for each inlet, and the simultaneous inrush current surge from both transformers is what's causing the supply to trip. It sounds like the inrush from one transformer alone is below the rating of the trip on the shorepower supply.
 
Could it also have something to do with the American 220V system is max rated at 50 Amps as opposed to our 16 / 32 Amp? (2 x 110V @25A with common neutral)
 
BruceK said:
Could it also have something to do with the American 220V system is max rated at 50 Amps as opposed to our 16 / 32 Amp? (2 x 110V @25A with common neutral)
Click to expand...

I might be missing your point a bit here (if so - sorry) but how is there a common neutral with a twin step-up transformer installation?
 
Hi Jimmy. It so happens that a week or two ago a similar fault was being discussed on the FB Trawler Living and Cruising group. It piqued my interest as I also have an American boat albeit now converted to EU standards. The fault turned out to be the common neutral, but what fascinated me was their approach to220V. You need to be a member but here is the link:

https://www.facebook.com/groups/tra...tif_id=1528917271753234&notif_t=group_comment
 
You must log in or register to reply here.

Share this page

Top