Step down transformer for isolation on boat.

[s/v Jedi]

Originally Posted by smac999

the guideline is for new built boats, built after the code was made like 6 years ago. and likely boats that are rewiring would have to follow current guidelines.

there is no requirement to update an existing boat to current codes. you'd be changing stuff every year if had to do that. and houses would be torn down every 5 years.

if the isolation transformers are within 10' of the shore inlet there is also no requirement to have elci breakers with the current code either.

the elci breaker requirement is for new boats without isolation transformers.

but if you are required to add them, then you would need 3 of them, one for each input... and they are not cheap

100% correct. As he has 3 shore power inlets but only 2 isolation transformers, the requirement for that 3rd inlet would stand for a new boat.

Unless this boat is less than 6 years old, it seems the inspector got it wrong, but maybe it was just a suggestion.

With an isolation transformer there is no benefit for an ELCI over regular breaker, which is why ABYC lists this as an exception. The big benefit would be to install ELCI in shore power pedestals at the docks. It is the power cord hanging in the water that poses the danger for boats with isolation transformers.

[team karst]

Originally Posted by DShant

…..Not really sure what to do and not really happy about the requirement.



I don't see many swimmers in my marinas and I have never heard of a swimmer getting electrocuted.

No bottom scrubbing divers work there? [emoji30]

[rgleason]

Like DShant, I am not terribly familiar with ELCI, galvanic isolator, etc. Our surveyor advised two years ago, that we did not have an AC panel and that we should have a basic one with ELCI (We are never, well hardly ever, at a slip). Very little room for this, but I think it could be mounted in a Waterproof ELCI in the port cockpit locker.

We have the standard 30amp American shore power plugin (not 50amp)! Which is 120vac x 30a =3.6kw I found this first diagram to possibly help with wiring, which shows:

1. Shore power stand
2. Shore power cable with two connectors.
3. Boat-Shore Power cable connection
4. Main Shore Power Disconnect Breaker with ELCI
5. 1:1 Isolation Transformer.
6. Then 120vac Ground Fault Interrupt Plugs and GFI 120vac breakers.

LATER: Victron Energy ITR050362041 Isolation Transformer 3600W with autodetect input voltage $840
As I understand it, the 1:1 Isolation Transformer is the best way to comply, and some people absolutely insist on it for complete safety, saying that a galvanic isolator is inadequate. This is very expensive (Let's not get into this discussion on this thread.)

However a waterproof Yandina galvanic isolator for 30a or 50a and 115v or 230v can be used instead, which is not as expensive and meets ABYC standards. This just prevents flow of current on the green ground with some mosfets, I believe. See the wiring diagram in the attached pdf.

1. Shore power stand
2. Shore power cable with two connectors.
3. Boat-Shore Power cable connection
4. Main Shore Power Disconnect Breaker with ELCI
5. Galvanic Isolation on the green wire
6. Then 120vac Ground Fault Interrupt Plugs and GFI 120vac breakers.

Jedi wrote:

So this is why we have two shore power connections. The first one is 3.6kW using the Victron isolation transformer so it can use either 120V/30A or 240V/50A and whatever input, make it into a 240V/15A output

We just have the 3.6kw 30a 120vac connection, but can use that Yolanda Isolator.

Jedi wrote

For optimum protection while on shore power, I use an EMS (Electrical Management System) that not only has surge suppression, but also a contactor and it will only pass power when it’s safe to do so, checking everything from under voltage, over voltage to frequency etc. This model is for a US 50A 120/240 connection, but there are many models incl. portable ones that go on the pedestal on the dock.
https://www.amazon.com/gp/product/B003AN1UA8

Is this wired in addition to the Main Shore Disconnect with ELCI?

Why are we talking about Victron and Mastervolt? It doesn't make sense. (LATER now I understand)


I don't follow all of this discussion, simply put, what is the diagram for shore power that we should use? What is optional?
What You Need to Know About ELCI-Protected Shore Power

also https://panbo.com/gfci-and-elci-brea...their-warning/
also http://assets.bluesea.com/files/reso.../YCDI_ELCI.pdf



Equipment Leakage Circuit Interrupter (ELCI) ground fault protection breakers. ELCI breakers can be on the shore post or on board.
I also did not know what RCD is! current ABYC standards include ground fault protection with an onboard ELCI (sometimes known as an RCD – Residual Current Detector).

[goboatingnow]

RCd is the generic term. Widely used in Europe. Usually combined with a rated circuit breakers and typically the. Known as a RCBO

[DShant]

Originally Posted by team karst

No bottom scrubbing divers work there? [emoji30]

Ha good point! Forgot about them

[DShant]

Jedi wrote. “100% correct. As he has 3 shore power inlets but only 2 isolation transformers, the requirement for that 3rd inlet would stand for a new boat.”

Actually two of the cables go to one transformer and the third which was added later goes to the other. Old boat upgraded for more AC

Some people think this should not be a requirement. Can you point to some formal source for this so I can argue with the surveyor and insurance? I would like to delete this which they have made mandatory for renewal of insurance.

[rgleason]

It seems like overkill to have ELCI on both the shore pedestal and onboard.
Shouldn't the marina do it, then all boats would be protected?

Why isn't ELCI onboard optional, ...just make the marinas do it?
I suppose the galvanic isolator would be good to have, but is that optional?

For optimum protection while on shore power, I use an EMS (Electrical Management System) that not only has surge suppression, but also a contactor and it will only pass power when it’s safe to do so, checking everything from under voltage, over voltage to frequency etc. This model is for a US 50A 120/240 connection, but there are many models incl. portable ones that go on the pedestal on the dock.
https://www.amazon.com/gp/product/B003AN1UA8

Would the EMS version for 120vac 30a EMS-LCHW30 https://www.amazon.com/gp/product/B004A32CGI?th=1 take the place of an ELCI breaker? No, it doesn't look like it would, there is no breaker operation.

I think all I would want:

1. Waterproof box to fit everything (but it might get too big)
2. 30a 120vdc ELCI Breaker (optional?)
3. Yolanda galvanic isolator (optional?)
4. EMS-LCHW30 Surge suppression (optional)
5. 15a house circuit GFI Breaker
6. DHW Breaker GFI
7. Refrigeration Breaker GFI

[goboatingnow]

Good idea to have both boat and marina pillar fitted with RCDs.

[DShant]

Originally Posted by goboatingnow

Good idea to fit them anyway they add significant additional safety to those onboard too

What additional safety do people on board get? If it's significant I might put them in even if I could argue them away.


From this thread it seems you could put them on each individual incoming line before the isolation transformer presumably if you are trying to protect people in the water??



By the way it seems that every few years there is some new gadget you are required to have. GFCI's were new when I was younger then we have arc fault breakers now these RCD/ELCI. I hope we are getting a lot of value for all the headache and expense.

[goboatingnow]

The big advantage of whole boat RCD is you don’t care about the ground return path. You don’t even need to provision for it. If the fault current returns to the source not by the neutral or phase live thd rcd will trip.

In my marina there are three RCDs on the feed before it gets the the marina pillar , one in the pillar , one in my shore power cable and one on my AC panel

I have the on my invertors also. I mean they cost about € 12

[boatman61]

I used one of these on an American 120v Hunter 37c I took to the UK..
Worked an absolute treat taking 240v down to 120v and 12v.

[s/v Jedi]

Originally Posted by DShant

Jedi wrote. “100% correct. As he has 3 shore power inlets but only 2 isolation transformers, the requirement for that 3rd inlet would stand for a new boat.”

Actually two of the cables go to one transformer and the third which was added later goes to the other. Old boat upgraded for more AC

Some people think this should not be a requirement. Can you point to some formal source for this so I can argue with the surveyor and insurance? I would like to delete this which they have made mandatory for renewal of insurance.

I don’t think it is compliant to wire two inlets to one transformer, so it may be worth getting this done properly. See my reference diagrams showing this.

About ELCI being a requirement: it makes no sense at all for boats who have an isolation transformer, which is why they are exempted from this. It isn’t a thought/opinion but simply fact, recorded in ABYC 11.11, see attachment.

[s/v Jedi]

I have posted diagrams that show every little detail but I’ll repeat just the part that is discussed in this thread here.

This diagram shows three power sources:

1. 3.6kW shore power connection with isolation transformer. This is what everyone should consider who don’t need more than 3.6kW. For US boats, you have the inlet, then a maximum of 10’ of 10AWG cable, then a regular, double pole breaker of 30A, then the transformer, then on the output, another 30A breaker, followed by the wiring to the input selector switch or straight into an inverter/charger.

US boats can also take 240V from shore but 120V is always available so there’s no need for this.

For EU boats you put a 30A or 32A breaker on the input and a 16A breaker on the output. The reason is that you can take US 120V and let the transformer make 240V from that for use aboard. This doubles current in the shore power cord.

You don’t need an AC input panel. Just buy DIN rail breakers and a small DIN rail box.

2. A 12kW 120/240V 50A shore power connection with surge suppression, Progressive energy management system and Yandina galvanic isolator.

I used a galvanic isolator here because at 12kW the transformer becomes huge and heavy, plus marinas that offer these high power connections are much more likely to have good systems. If you don’t put in the Progressive unit then you must replace the breaker with a RCD type 30mA which is also available for mounting on the DIN rail.

3. A 6kW diesel genset.

This isn’t a reference diagram, it is my actual diagram so it outputs only 240V. If you have 120V then you have a Neutral instead of my (red) L2. If you have 230V EU then you also have a neutral and there is no Progressive unit available, so you must use a RCD breaker and can add a surge protector which is also available for DIN rail.

[rgleason]

Nick, Thank you for the diagrams. Looking at the first example, but without an inverter.

1. 3.6kW shore power connection with isolation transformer. This is what everyone should consider who don’t need more than 3.6kW. For US boats, you have the inlet, then a maximum of 10’ of 10AWG cable, then a regular, double pole breaker of 30A, then the transformer, then on the output, another 30A breaker, followed by the wiring to the input selector switch or straight into an inverter/charger.

Would this be ok to meet ABYC?

1. Waterproof DIN box $20 to fit everything in the port cockpit locker.
2. Main Breaker ELCI 30a 120vdc DIN ASI Ndb1l-32c-16-120v $35
3. Yolanda 204577 galvanic isolator. $79 (Within 10')
4. House Breaker ELCI DIN 120vac 15a NDB1L-32C-16-120V
5. DHW Breaker ELCI DIN 120vac ??a NDB1L-32C-16-120V
6. Refrigeration Breaker ELCI DIN 120vac ??a NDB1L-32C-16-120V
7. Is there a smaller 1 pole breaker that I could use instead for the smaller circuits? (Later: These are 1 pole)
8. Do I even need ELCI breakers for #4,#5 &#6 Breakers? Maybe something smaller from these?
9. Add 2 Blue Sea 120V LED indicators for "power present" indicators and "reverse polarity" indication. Wire the LED's to the breaker and ground lug, and drill holes in the DIN box to house the LEDs.
10. Isn't this surge protector something in addition to the main breaker? 2 Pole 1 Piece Protection Device DIN Rail Mount Surge Protector Low Voltage Device 10-20KA 420V Electronic Lightning Protection

Peter Kennedy on Isolation Transformer or Galvanic Isolator - which is preferable?
If you have the room and the money and are going world wide cruising you want a transformer.

[smac999]

Originally Posted by DShant

Actually two of the cables go to one transformer and the third which was added later goes to the other. Old boat upgraded for more AC

how are you running 2 shore cords into a single transformer? are they paralleled for more power? or do you have a port / stb transfer switch so you can tie up on either side and only use one at a time?

if using both at the same time there is good chance you'd just blow the elci breakers and you'd never have any power