Boost Volts from 208 to 230

[Seevee]

What would one need to boost the power at a marina that's low, ofter 208 volts or 104 volts, when you need 240 or 120?


What transformers are available that will do this boost?


Note: I have one on my Mainship, a Charles 93-IXFMR12I-A Isolation Transformer.


However, it's a big clunky thing and shopping for another boat that doesn't have a transformer.



Solutions?

 

[garmstro55]

I posted my solution here: https://www.trawlerforum.com/forums/s11/ms400-low-dock-voltage-~100volts-solution-51268.html

I found it on the Red Pearl site and did the same thing. It works!

 

[jhall767]

I installed one of these on my boat. It will boost or lower the voltage as needed automatically.
https://angconverters.com/ang-boost-2/

A boost transformer will protect against improper 208V transformers,
reverse polarity and the new GCFI pedestals.

 

[caltexflanc]

Isolation transformers are something you want to have no matter what the issue you have with their "bulk".

Two solutions have been shown here. The Iso-Boost (formerly marketed by Charles prior to their exit from the marine industry) is the most expensive and elegant and no-brainer, as they automatically sense the need, and then lack of need. We had them on our old Hatteras compliments of the PO. Wonderful.

When you tap a transformer to create a switchable boost, it is very important to understand that it will boost every voltage level coming in, so leads to severe over voltage, say when you get to a 250 volt dock. So you need some sort of big red flag reminder to switch it off.

An in between solution is to get a "buck boost" transformer that you plug your shore power cord into and then plug the transformer into the dock outlet. Such as the one sold by Ward's. Scroll down to page 3. Bulky to schlep around, but more foolproof than the switched tap solution.

For it and the switched tap solution note bene the warning about using it at marinas with voltage variation issues. It is not always due to a 208v situation. You may be at the end of the dock, then a bunch of people down the dock show up and turn their air conditioning on start cooking a meal in their electric galley. We witnessed this in observing our Iso-Boosts switch on and off.

https://2486634c787a971a3554-d983ce...s-marine/media/transformers-5dcaa98d43a1c.pdf

 

[jhall767]

Isolation transformers are something you want to have no matter what the issue you have with their "bulk".

Two solutions have been shown here. The Iso-Boost (formerly marketed by Charles prior to their exit from the marine industry) is the most expensive and elegant and no-brainer, as they automatically sense the need, and then lack of need. We had them on our old Hatteras compliments of the PO. Wonderful.

When you tap a transformer to create a switchable boost, it is very important to understand that it will boost every voltage level coming in, so leads to severe over voltage, say when you get to a 250 volt dock. So you need some sort of big red flag reminder to switch it off.

An in between solution is to get a "buck boost" transformer that you plug your shore power cord into and then plug the transformer into the dock outlet. Such as the one sold by Ward's. Scroll down to page 3. Bulky to schlep around, but more foolproof than the switched tap solution.

For it and the switched tap solution note bene the warning about using it at marinas with voltage variation issues. It is not always due to a 208v situation. You may be at the end of the dock, then a bunch of people down the dock show up and turn their air conditioning on start cooking a meal in their electric galley. We witnessed this in observing our Iso-Boosts switch on and off.

https://2486634c787a971a3554-d983ce...s-marine/media/transformers-5dcaa98d43a1c.pdf

Quite right on the voltage. Can be too high or too low. And can change while you are away from the boat. My transformer cuts out when it get's too far out of range and it can't be corrected. It suspended power when the incoming voltage got over 260 and it couldn't drop it back to a safe level for the equipment.

 

[caltexflanc]

Quite right on the voltage. Can be too high or too low. And can change while you are away from the boat. My transformer cuts out when it get's too far out of range and it can't be corrected. It suspended power when the incoming voltage got over 260 and it couldn't drop it back to a safe level for the equipment.

Yes, that is one of the beauties of the Iso-Boost system. But 260 is fortunately a pretty rare occurrence on the American electrical grid. Just imagine having a constant boost solution even at 240 or 250.

 

[tiltrider1]

There is another option as well. You can take any circuit of 120v and use a transformer to turn it into 240. If you have 50a of 120v you will be limited to 25a of 240v. If this is sufficient you won’t need to worry about 208v or finding two 30a plugs that are out of phase. This method can be done with or with out isolation transformers.

 

[FF]

Remember any "boost" transformer will boost the amperage required from the power cord.

V x A = W so the voltage may rise , but there will be fewer amps to run your gear.

Sounds like the location is set up for 3 phase , not std house current?

 

[sunchaser]

What would one need to boost the power at a marina that's low, ofter 208 volts or 104 volts, when you need 240 or 120?

Many dock power installations are designed for 208. Ours are with no ill effects. It seems then that the question really comes down to is the 208 by design or by poor dock electrical installation?

If one's dock wiring is designed for 208 why bother with an IT addition to fix a non existing problem?

 

[Woodland Hills]

Many dock power installations are designed for 208. Ours are with no ill effects. It seems then that the question really comes down to is the 208 by design or by poor dock electrical installation?

If one's dock wiring is designed for 208 why bother with an IT addition to fix a non existing problem?

If the dock voltage is too low, our a/c will not run. It just throws a “low a/c” code. Plugging in the boost transformer gets the boat cooling again.

 

[Seevee]

Great info, thx.


Yes, the issue is mainly with the AC unit. I've never had an issue with high voltage, only low volts. However, I've found it quite common, perhaps 15 to 20% of the marinas I've patronized.



Some motors and circuit boards could be damaged with low voltage, so want to keep it close.



I do have the Charles transformer on my current boat with a mod that boosts the voltage which works great, but shopping for a different boat.

 

[Choices]

A voltage swing of 10% is allowed. Typically 208 is done to balance an electrical circuit.

Your isolation transformer may have taps you can change. Some have 2) at 2.5% above and below nominal voltage. So that gives you a 5% boost by design.

You will have to change taps for different marinas...

 

[bayview]

208 is used in many industrial applications. It may be correct and standard at your dock and not indicate a problem. My boat ran close to the breaker limit with all ACs running and everything else going on 208 V docks. I didn't like it but it worked.
I was careful to check power cords for over heating. I just dont think things are meant to run at their limit for long.

 

[caltexflanc]

A lot of older equipment on boats, such as AC equipment is not designed to run on 208, and some, such as kitchen equipment don't work as efficiently. As noted by FF, energy is measured in watts. So if volts go down, an appliance that requires a certain wattage will consume more amps to work correctly.

One work around used at 208 marinas is to get a Smart Y and hook it to opposite phase 30 amp outlets, Resulting in lower amperage capacity but delivering full voltage. We used ours on a few occasions when no 50/250 outlet was available typically for one transient night. We didn't enjoy managing loads, Ann once asked me why I hadn't bought two of them; I replied that the marinas typically frowned on one boat using four outlets. The Mainship 430 we used to charter supplied one as well, and there were places up in the Delta where it came in handy. But if there aren't two out of phase outlets, then the only choice is to turn on the generator, seldom a popular move in marinas with a lot of people on board.

 

[jhall767]

I don't know where some if this information is coming from but unless you are running three phase 208V is not correct. The marina may be wired that way but that is because the wrong (cheaper) transformer was installed. The 120V circuits are fine. It's only the 240V that doesn't work properly.

208V is the three phase voltage rating. There are three 120V legs or phases that are 120 degrees apart and the "voltage" between any two legs is 208. A/C equipment can run on that but it not the same as low voltage on a 240V circuit in which the two 120V phases are 180 degrees apart. It is not as efficient which also causes a larger current draw in addition to the lower voltage.

In the US the utility companies are required to provide 240V as the primary circuit for residential use.

 

[caltexflanc]

I don't know where some if this information is coming from but unless you are running three phase 208V is not correct. The marina may be wired that way but that is because the wrong (cheaper) transformer was installed. The 120V circuits are fine. It's only the 240V that doesn't work properly.

208V is the three phase voltage rating. There are three 120V legs or phases that are 120 degrees apart and the "voltage" between any two legs is 208. A/C equipment can run on that but it not the same as low voltage on a 240V circuit in which the two 120V phases are 180 degrees apart. It is not as efficient which also causes a larger current draw in addition to the lower voltage.

In the US the utility companies are required to provide 240V as the primary circuit for residential use.

Thanks for articulating, all are points well taken.

 

[sunchaser]

To add a bit more. In a 3 phase circuit 208 volts is the line to line voltage. Whether at marinas or lesser electrical use businesses this 3 phase voltage is frequently used. But the line to neutral voltage is 208/1.732 (square root of three) or 120 volts.

So Seevee, is your marina power 3 phase? Our 208 volt marina in BC has never given us any trouble.

 

[FF]

In some cases the "marina" was a working boat yard so 3 phase would be chosen to power motors.

Not the best for 120/240 use , but some equipment will survive .

The correct transformer is worth the effort. google the methods.