Combining 50A and 30A Galvanic Isolator

[HBWT]

Our Hans has a 30amp and 50amp shore power inlet connection. Up to this point, we only used the 30amp due to:

1-not having a 50amp power chord
2-The 50amp ground wire does no have a galvanic isolator installed.

The 30amp ground does have a Promariner 30amp galvanic isloator. So that got me thinking. Both grounds go to the same grounding bus, why cant I get rid of the 30amp gavanic isolator and add a 60amp and connect both 30amp and 50amp ground wire to the same isolator. The 50amp and 30amp will never be plugged in at the same time so no concern overloading the system.

I cant see any downside to this but I leave this to the better judgement on CF.

[hellosailor]

"The 50amp and 30amp will never be plugged in at the same time"
Nice theory. But unless it is physically impossible to do so--I'd look for an 80A not a 60A.

[HBWT]

Originally Posted by hellosailor

"The 50amp and 30amp will never be plugged in at the same time"
Nice theory. But unless it is physically impossible to do so--I'd look for an 80A not a 60A.

I understand making things idiot proof, but If I am dumb enough to plug in both a 50amp shore power and a 30amp shore power into the dual seperate receptacles, I deserve the stupidity that is coming to me and should not own a sailboat or let alone leave the house for fear of imminent death.

You can't fix stupid.

[hellosailor]

It is not a question of whether you are dumb enough, but if someone else is left on the boat, or gets on the boat, or some other "Oh, that's never gonna happen" happens. Good engineering looks at those things and makes them impossible. Sadly, that encourages the survival of the non-fittest. But sometimes, it prevents fatigued people from going "oops" as well. Sometimes worth considering.

[smac999]

both would be running through a transfer switch so even with both pluged in, only one could have current. I would do it.


though since you already have the 30, and are buying a 60. I would run both.


if you didn't have either to start with, I would buy the 60 and put in only.

[boatpoker]

Next time you have an insurance survey, a savvy surveyor will catch it and your insurer will make you change it anyway.

[boatpoker]

Originally Posted by smac999

both would be running through a transfer switch so even with both pluged in, only one could have current.

Then you could have 50amps running through a 30amp isolator !
Sleep well

[smac999]

Originally Posted by boatpoker

Then you could have 50amps running through a 30amp isolator !
Sleep well

the topic of this thread is replacing his 30 with a 60

[HBWT]

Originally Posted by smac999

the topic of this thread is replacing his 30 with a 60

Exactly, I would remove the 30amp isolator and install a 60amp. Why 60amp? It looks like most companies do not make a 50amp, so 60amp is the next best. This would allow me to save space and time by running both ground wires through the same isolator. If I was running 30 amp shore power, no problem, or 50 amp shore power, no problem. Again it seams to my novice mind that this is a win/win but...

[boatpoker]

Originally Posted by HBWT

Exactly, I would remove the 30amp isolator and install a 60amp. Why 60amp? It looks like most companies do not make a 50amp, so 60amp is the next best. This would allow me to save space and time by running both ground wires through the same isolator. If I was running 30 amp shore power, no problem, or 50 amp shore power, no problem. Again it seams to my novice mind that this is a win/win but...

Only if you also put in a lock-out transfer switch too.

[smac999]

Originally Posted by boatpoker

Only if you also put in a lock-out transfer switch too.

this is required with or without the galvanic isolator... otherwise the other shore plug would go live.

[exMaggieDrum]

Originally Posted by smac999

this is required with or without the galvanic isolator... otherwise the other shore plug would go live.

Absolutely correct!! And the switch should be before any loads with no possibility for the shorepower inlet on either side to go hot from an inverter.