Voltage issue causing Cruisair units to shut off

[Hat43c1981]

All,

I hope everyone is doing well and enjoying the start to a great boating season.

We own a 1981 43' Hatteras Convertible that has (2) 16,000 btu Cruisair split A/c units. Every once in a while I will get a "LO AC" code on the thermostat which I read is a safeguard for the compressor where it shuts off if the voltage drops below 208 volts. Fast forward to this afternoon. I communicated with the dockmaster at our yacht club about the voltage drop issue coming in from the pedestal and he advised me the marina runs off of a 208v system and that I would either need to replace the a/c units (not in the cards) or get a voltage booster. I am not familiar with a voltage booster. Has anyone had this same issue? If so what did you do to remedy the problem minus replacing the perfectly functioning a/c units.

Thanks in advance!!

 

[Boatsb]

Your marina is wrong. They should supply 125/250 volt power. The 208 3 phase their using is not propper.

I added an automatic buck boost transformer to a customers boat recently for that and other reasons (isolating an aluminum boat is important) for about $6k. Ask the marina to pay for it and see what they say.

 

[Captain Ralph]

Re-calibrate your displays to a lower voltage. Directions are in the manual.
If your on 208Vac, the compressors are fine.

 

[SKYCHENEY]

This is a common problem. The compressors will run hotter and draw more amps on the lower voltage. Will they be okay? For a time, yes, but in the long run you're better off boosting the voltage.

 

[Captain Ralph]

Boosting voltage lowers available current. Nothing is free.
Look on the compressor tag or ask Dometic to verify per serial number if 208Vac capable.

 

[Avenger]

And high current causes overheating. Nothing is free.

 

[Hat43c1981]

Thank you for your insight/input on this issue I am having. I am looking at a stand alone unit that will sit by the pedestal for the time being. I will also be looking into the voltage for the a/c units with Cruisair/Dometic.

 

[Hat43c1981]

I will plead my lack of understanding with voltages and how different setups can alter it. Would it solve my issue if I ran a 50amp Y adapter from the pedestal to (2) 30amp shore power lines coming into the boat? Trying to think outside the box here.

Thanks!!

 

[Photolomy]

I will plead my lack of understanding with voltages and how different setups can alter it. Would it solve my issue if I ran a 50amp Y adapter from the pedestal to (2) 30amp shore power lines coming into the boat? Trying to think outside the box here.

Thanks!!

That would not change anything. The two 30A circuits, if they are out of phase, would also be out of phase by 120 deg, rather than 180 deg as they are in a true split system. It is that difference that causes marinas with 3 phase power to have 208v instead of 240v, even though their 120v is 120v. Thus, when you add two 120v together, you get 208, not 240, because the phase difference is 120 deg, not 180 deg.

 

[Boatsb]

Look at some marinas with huge transformers around or going down the docks. These are usually the ones that invested in the power system.

Some larger vessels (usually commercial) are set to run on 3 phase. They have issues when powered by 240 volt single phase.

Remember the compressor is rated for a voltage. Sometimes a range in voltage but with lower voltages come higher amperage and heat.

This is why many boats have 120 volt air conditioning instead of 240 volt units.

 

[jim rosenthal]

As pointed out correctly, nothing is indeed free. Transformers which raise voltage decrease amperage. I wonder if the dockmaster is correct that the marina is supply 208 volts. I'd measure that and see what it actually shows when you read the voltage from the shore power pedestals with a digital VOM.

 

[SKYCHENEY]

Boosting voltage lowers available current. Nothing is free.
Look on the compressor tag or ask Dometic to verify per serial number if 208Vac capable.

Available current will never be an issue with a 43 that only has two air conditioners.

 

[Hat43c1981]

Thanks for all of the input! I spoke with our Dockmaster today and had him take a voltage reading at the pedestal and it was 202v. He has a buck/boost transformer set up I can use until I find a more permanent set up. He then took a voltage reading with the buck/boost transformer connected and got a reading of 232v. I am going to see if I could purchase the transformer set up from him and have it as a permanent set up at our pedestal. I attached a picture of the transformer set up. Do you all believe the systems in our boat will function better at the 232v verses the 202v? I.e. range/oven, a/c units, electrical Jenn Air grill etc. Thanks in advance

 

[Captain Ralph]

Probably need to discuss this with your insurance agent also.

 

[Boatsb]

Good idea.

Your insurance agent will be happy your addressing the issue

 

[SKYCHENEY]

Thanks for all of the input! I spoke with our Dockmaster today and had him take a voltage reading at the pedestal and it was 202v. He has a buck/boost transformer set up I can use until I find a more permanent set up. He then took a voltage reading with the buck/boost transformer connected and got a reading of 232v. I am going to see if I could purchase the transformer set up from him and have it as a permanent set up at our pedestal. I attached a picture of the transformer set up. Do you all believe the systems in our boat will function better at the 232v verses the 202v? I.e. range/oven, a/c units, electrical Jenn Air grill etc. Thanks in advance

This is a good setup. Your electrical motors and compressors will run cooler and draw fewer amps.

 

[Olde Hatt]

I had a very similar issue at a marina. The marina provided a Buck/Boost transformer and everything worked just fine. They told me that they kept a couple units for boats that had this same issue. I had no adverse issues using this hook up for about two months. I was later told that this is an issue in older marinas that not upgraded their systems.