120V step up to 240V needed

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jhall767

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I have a 240V isolation transformer that, per the manufacture, cannot work on a single 120V feed. Occasionally 240V is not available at the slip or on the hard. Thus no power or using the 30 amp combiner. I'm looking for ideas on the best way to adapt the input so it can use a single 120V power cord..

I'm thinking a portable transformer with a 30 amp plug and a 50 amp 240v receptacle to plug the shore power cable into.
I see these on Amazon rated 5KW but with only a 15 amp plug on them.

Any thoughts?
 
jhall767 said:
I have a 240V isolation transformer that, per the manufacture, cannot work on a single 120V feed. Occasionally 240V is not available at the slip or on the hard. Thus no power or using the 30 amp combiner. I'm looking for ideas on the best way to adapt the input so it can use a single 120V power cord..

I'm thinking a portable transformer with a 30 amp plug and a 50 amp 240v receptacle to plug the shore power cable into.
I see these on Amazon rated 5KW but with only a 15 amp plug on them.

Any thoughts?
Click to expand...
Thanks for the post. I've never thought to check my transformer for the conversion. Looking forward to seeing what you come up with.
 
I'm looking at a Yinleader power converter. Something like this with a 30 amp plug for input and a 50 amp receptacle for the boat to plug into.

There are other but they all seem to have regular plugs and would be limited to 15 amps by the plug.

The next setup up seems to be a victron autotransformer. But it's pretty big and pretty expensive.
.
 
Slow down folks. You are headed in the wrong direction.

Your boat uses 50a 125/250v system. This means means you have two 125v legs out of phase with each other. Your appliances pick up both legs to get 240v.

What you are looking at is a device that is designed to convert a single 125v leg into a single 240v leg. This is not going to work at all.
 
tiltrider1 said:
Slow down folks. You are headed in the wrong direction.

Your boat uses 50a 125/250v system. This means means you have two 125v legs out of phase with each other. Your appliances pick up both legs to get 240v.

What you are looking at is a device that is designed to convert a single 125v leg into a single 240v leg. This is not going to work at all.
Click to expand...
No, I don't think you understand the problem. I have an isolation transformer that cannot operate on 120V. It needs 240V input. I am sometimes faced with only having 120V available in which case I cannot use any shore power. I do have a dual 30 amp combiner but that needs dual 30's that are not on the same phase.
 
Remember that 120V/30A, if properly transformed, means you're limited to 15A@240V. Is that enough to be useful? You may be better off, depending on your inverter capacity and power distribution, to go with a dedicated 120V charger that merely converts 120V/30A AC power to 12V or 24V DC power at 240A/120A respectively and feeds that to your battery bank and inverter bus.
 
So if your isolation transformer doesn't have a neutral, why can't you use a 30 amp combiner without the neutrals? Obviously you will need to find two 120 VAC outlets that aren't on the same phase.

If you have no 240 VAC equipment, it would also be possible to use a rotary switch to bypass the isolation transformer and combine both 120 VAC legs to be powered off a 30 amp inlet. The Rotary switch should be configurable to eliminate operator error (plugging in both cords at the same time). My boat was wired 50 amp 125 / 250 VAC without any 240 VAC equipment. I was able to use:

50 amp 125 / 250 VAC
Two 30 amp 125 VAC
One 30 amp 125 VAC
One 15 amp 125 VAC.

Ted
 
tiltrider1 said:
I did understand your issue. You need to go from single phase to split phase.
Click to expand...
I think his existing isolation transformer takes care of that part. They accept 240V input, ignoring the shore neutral which is often dropped out of the cable as well, the create 120/240V split phase on the secondary side.

To the OP, do you have a manual or wiring diagram for your isolation transformer? There is typically a plaque on the transformer itself showing all the connections. I just want to confirm that it can't be re-wired to accept 120V input. Some/many can.
 
Twisted tree is correct. Need to get from 120 to 240V. Transformer should split back to 120V. The transformer is an ang-boost 12kw. Usable wattage will depend on the 120V circuit. 15, 20 or 30 amp. Won't be able to run everything but enough.

And I just heard back from the manufacture that it will work.
From them "the output will be 120V+120V+240V (120/240V + N)"

When I have some time I'm going to order one of these from Amazon and see if it actually works,. I'll report back.

Yinleader 5000W PRO Voltage Transformer Converter Step Up/Down AC 110V/120V to 220V/240V or 220V/240V to 110V/120V Power Converter w/US Standard Power Cord,Circuit Breaker Protection​

 
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