125vac isolation transformer

[Tom power]

Just a question for any guys with good electric knowledge. I have a 48 hat LRC with a separate solar panel/inverter/deep cycle battery bank that I installed. Have a generator transfer switch (2 generators) that has off/inverter/gen 1/gen2. This works okay but my inverter only puts out one leg of 125vac so had to jump this leg to service both legs on the transfer switch. Thus all my 125vac works just fine on all the panels but of course no 250vac as both legs are the same phase.Would like to switch through one of my 50 amp 125vac shore power inlets but was wondering what the parasitic load us on the 125vac transformer would be as these transformers seem to get quite warm so must use a fair amount of energy whether transforming or not.I had originally hooked up system through this transformer but seemed to draw a lot of current. Anyone familiar with this kind of electrical issue.

[Boatsb]

Thats why I recommend 2 invdrrters to serve the 250 volt and either side for 125.

It also charges faster as there's 2 chargers.

I just sold a victron multi 2000 inverter to a member. He didn't need 250 volt or he would have bought 2 and set 5gem up as a 125/250 system

If you were to have 2 you could set them up as a pair and solve all those problems but not all inverters can do that.

[SKYCHENEY]

I just rewired a Hatt so that the inverter was NOT feeding the isolation transformer. It had been that way for 20 years, but the owner thought he would get longer inverter run time if it wasn't set up that way. I have no idea how much it draws.

[Tom power]

Yes I hear you. When I originally installed my inverter I took one of the two 125vac 50 amp shore power leads that come into the cockpit off the back of one of the inlet recepticles so inverter fed this and was running through the small transformer. Seemed like it used a lot of parasitic current so I just got a 4 position generator switch and changed the inverter to that. Actually works much better there and s lot less switching when cruising and going between gen set and inverter. So as you say much better that way. I was just curious just how much current was lost when isolation transformer not just sitting in standby . Seemed to me it might be at least 100 watts maybe more. Do you have any idea on this?

[Boatsb]

Ive never fed an inverter to a transformer. It makes no sense unless you try to use a 220 volt eurolean model and have the transformer create the 2 legs. (Not my idea but I've heard of people doing it)

The inverters will output what the get on input when they have power. To use them as amp boosters you need to wire them in line with the feed.

The best systems I've installed have 2 inverters in line between the source selector and the panel and tbeir large enough to feed the whole vessel (50 amp pass through) And when on batteries they will manage the genny to bring up extra power when needed.

They have 2 inputs 1 genny and one shore that they switch between and 2 outputs so large draws do not pull from the batteries unless you want them too.

If planned correctly they make an almost transparent user interface.

[Tom power]

Okay I could well be confused. I thought the 50amp 125 Hatteras transformer was tapped off for 2 out of phase 125 vac legs each if about 25 amps. Not sure why I thought this. Do

[Boatsb]

50 amp 125/250 has 50 amps on each leg. That means both 125 volt legs are 50 amps and theref9fe the 250 volt is 50 amps too.

[SKYCHENEY]

The Hatt iso-trans can be fed with a single hot leg and produce 220v as the OP is trying to do. Most of the boats have switching to feed the transformer from a separate 50a 125v inlet.

I have no idea why your would want to do this. If you need to run a 220v load, it will draw a bunch and you'd be better off just starting the generator.

[Tom power]

Hi thanks for response. Thought it worked like that. Some times I just want to run the stove top for a few minutes and with the solar panels putting out and my large battery bank I would have enough power. (Stove top is 240 vac)We live on and cruise the boat so this can cone up multiple times per day (almost always anchored out some times for months at a time) we