Step down transformer for isolation on boat.

[s/v Jedi]

Originally Posted by rgleason

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

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.

Doesn’t look anything like my diagram

You have all 16A breakers instead of 30A. No transformer so yes the breaker at the inlet must be a ELCI or RCD breaker but 30A, not 16A. Then the galvanic isolator. From there it’s straight into the inverter/charger. A surge suppressor can go on the DIN rail but is just connected in parallel.

[DShant]

Jedi Thanks so much for the reference. I will take it to the surveyor and see if I can get this "must have" item deleted for now. As to whether I do anything about it, I will look into it a bit more.



As to the question from you and Smac999 of two cables going to one transformer I misspoke a bit. I know I can run with three cables and I know I have only two transformers and I also know that one cable and one transformer were added in a refit in 2009.



I assumed the two other cables run through the old transformer that was put in when the boat was built as far as I know. I do not know how they are wired in. I will check on that next time I am there and also have an electrician take a look. I assume that Palmer Johnson knew something when they did it.



Gauges let me see amperage and voltage per line so I know its not somehow putting in 100 amps instead of two 50's. Strange I will have to investigate further

[rgleason]

Originally Posted by s/v Jedi

Doesn’t look anything like my diagram

You have all 16A breakers instead of 30A. No transformer so yes the breaker at the inlet must be a ELCI or RCD breaker but 30A, not 16A. Then the galvanic isolator. From there it’s straight into the inverter/charger. A surge suppressor can go on the DIN rail but is just connected in parallel.

That's right about the breaker being 16a, would this 32a be ok?
ASI NDB1L-32C-32-120V DIN Rail Mount Ground Fault Circuit Breaker, UL 1053 Ground Fault Sensing, Leakage Current 30 mA, 32 amp, 120V

I suppose some smaller breakers like ASI NDB2-63C10-1 DIN Rail Mount Circuit Breaker, UL 1077 Supplemental Protection, 10 amp, 1 Pole, 240V, General Purpose Trip Curve C would work for the refrig, DHW and House circuit, but it is 240vac. Does that matter?

[s/v Jedi]

Originally Posted by rgleason

That's right about the breaker being 16a, would this 32a be ok?
ASI NDB1L-32C-32-120V DIN Rail Mount Ground Fault Circuit Breaker, UL 1053 Ground Fault Sensing, Leakage Current 30 mA, 32 amp, 120V

I suppose some smaller breakers like ASI NDB2-63C10-1 DIN Rail Mount Circuit Breaker, UL 1077 Supplemental Protection, 10 amp, 1 Pole, 240V, General Purpose Trip Curve C would work for the refrig, DHW and House circuit, but it is 240vac. Does that matter?

It sounds like now you are doing AC distribution… this is about shore power. Distribution only comes after inverter/charger and a second panel/box with breakers, normally at/near the navstation.

You take two or three things, then tear them apart and try to morph into one new thing, like Frankenstein. It doesn’t work, there is nothing new to invent, everything has been worked out in the past 100 years.

You can eliminate parts of my diagrams, like remove the genset option or a selector switch when there’s only one selection, but you can’t just throw some stuff together and then ask if it’s okay to do so. No, it’s not okay. I have published my basic diagram, I will attach it here again. The only thing you can change is the breaker-transformer-breaker part. You can replace that with ELCI-breaker with galvanic isolator. The rest: ships ground busbar, inverter/charger, with output breakers (OUT2 can be eliminated if you wish) and distribution panel with breakers and ground, must remain.

[rgleason]

Thanks Nick. That is a very nice diagram, I wish I could do that, but it is a small boat, always on a mooring, hardly ever at a slip, there is no room and I don't anticipate having an inverter either.

Yes I guess I am making a frankenstein, for the few times we are at a slip, it would be nice to run the DHW hot water coil, the refrig 120vac connection and the two house outlets. I have no room for an AC panel inside the cabin, so it will have to be in the WP ELCI box in the port cockpit locker. It might be nice to also have a 120vac plug to plug in the portable 15a battery charger used to charge the batteries.


The reason for doing this is just to satisfy the surveyor's comment that I have no 120vac panel.

[s/v Jedi]

Originally Posted by rgleason

Thanks Nick. That is a very nice diagram, I wish I could do that, but it is a small boat, always on a mooring, hardly ever at a slip, there is no room and I don't anticipate having an inverter either.

Yes I guess I am making a frankenstein, for the few times we are at a slip, it would be nice to run the DHW hot water coil, the refrig 120vac connection and the two house outlets. I have no room for an AC panel inside the cabin, so it will have to be in the WP ELCI box in the port cockpit locker. It might be nice to also have a 120vac plug to plug in the portable 15a battery charger used to charge the batteries.


The reason for doing this is just to satisfy the surveyor's comment that I have no 120vac panel.

You are doing a significant lithium based system without an inverter nor a battery charger? AC powered hot water but no battery charger? You never stop to surprise me :-)

So in that case I recommend you delete all AC power facilities aboard and use an extension cord from shore straight to the water heater and refrigerator. But when you do a battery charger instead, you can keep fridge on DC and gain much extra.

[rgleason]

Well I do have a heavy shore power cord 30a 120vac cord and a WP fitting on the boat, which goes to a polarity tester/sounder, then to the 2 outlets.

I also have cords with 120v plugs for the Refrig and DHW, but I never use them, good point, maybe I will just not bother with those.

The LFP are going to be for DC power, don't need or want AC. LFP will be charged with alternator and solar. Trying to keep it simple.

[team karst]

https://www.westmarine.com/blue-sea-...4aAmygEALw_wcB

No room for this waterproof box? I show 50A but i have the 30a version. Pricy…

[s/v Jedi]

Here you go, $19 and you can pop a row of rcd/elci/breakers/terminal blocks on the rail: https://www.amazon.com/gp/product/B07S94Z7CF

Yes, you must have at minimum an approved inlet, rcd/elci, galvanic isolator and a distribution box with breakers. Most breaker panels have this AC section integrated.

[goboatingnow]

Originally Posted by s/v Jedi

Here you go, $19 and you can pop a row of rcd/elci/breakers/terminal blocks on the rail: https://www.amazon.com/gp/product/B07S94Z7CF



Yes, you must have at minimum an approved inlet, rcd/elci, galvanic isolator and a distribution box with breakers. Most breaker panels have this AC section integrated.

Yep available on all local electrical distributors two a penny

[rgleason]

Thanks very much that 6x8 will surely fit and satisfy the surveyor the galvanic isolator may need to be in a separate wp box.

[s/v Jedi]

Originally Posted by rgleason

Thanks very much that 6x8 will surely fit and satisfy the surveyor the galvanic isolator may need to be in a separate wp box.

Here are pictures of my installation. It shows breakers and terminal blocks in that housing, then it being installed in my engine room with the Yandina galvanic isolator and the Progressive EMS. Even the little remote for the EMS is installed there, because it has an override that may need to be used one day.

Not all breakers are the same brand/type because some values are only available in one brand etc. But because they are all DIN rail compatible, you can mix what you want

[goboatingnow]

Nice. Here I tend to use GARO rcd and breakers.

For my v2 ac panel I’m thinking of self resetting RCD devices

[CharlieJ]

@gbn

For my v2 ac panel I’m thinking of self resetting RCD devices

Not a great idea from a safety standpoint. If the RCD trips, the operator investigates with hands in the panelboard, the RCD resets, and the operator could receive a shock.

Not permitted by ABYC E-11 and ISO 13297 hints at not being permitted.

[goboatingnow]

Originally Posted by CharlieJ

@gbn


Not a great idea from a safety standpoint. If the RCD trips, the operator investigates with hands in the panelboard, the RCD resets, and the operator could receive a shock.

Not permitted by ABYC E-11 and ISO 13297 hints at not being permitted.

The issue is that thd boat is on tbd hard etc a remote rcd is awkward , the unit I mentioned has a step back reconnection times but only three times. If the fault exists the unit will trip again immediately so the shock risk is not increased.