AC voltage protector help!

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

the getaway

Veteran Member
Joined
Nov 17, 2012
Messages
28
Hello all, throwing out this question hoping for some help with this horrible shore power we have here in New Orleans. Just had my air conditioner compressor die from what I think is the voltage fluctuation at my marina. Read a post from Capthead about a voltage protector he hardwired in for $30. I searched and found some but they are all around $220 to $500. I'm not an electrician by any means, I'm just a boat owner that has turned into a jack of all trades since living aboard for the last 4 years. I need a solution to the low voltage situation we have here from time to time and protect the stuff that doesn't like it! Saw some tripp lite line conditioners that could possibly be rewired to fit my needs, but that is getting out of my comfort zone of amassed knowledge. I also saw the EMSHW30C that looks like what Capthead was talking about but that goes for $220. What is the best solution to my problem before I install the new AC unit next week? I have learned so much from y'all that i'm eternally grateful.
 
I'd love to see something worth a dang at $30...will be interested to see what pops up.

Usually the only thing I say I trust is a really nice transformer with voltage boost....everything else just doesn't seem to be likely to help IAW their claims and engineering. Plus you get stray current protection thrown in....

Maybe someone can post something that will change my mind....even the nice, expensive surge protector strips seem like a scam to me...they could make them out of modeling clay, buy group insurance and probably come out ahead just paying claims rather than actually manufacture an inexpensive product that does what it claims.

Just too many out there with people going WTF.????.."The reason why I bought the thing was to protect my computer/TV"....typical answer "don't worry the check is on it's way" is really not what you want to hear at that time.
 
Nothing is going to protect your equipment from low voltage except a transformer that will automatically boost it as necessary. You won't find this for anywhere near $30, probably more like $300. A computer surge protector is nothing like this and will not help you.

The other option is to install something that will shut your equipment down if the voltage is too low for safe operation.
 
I would rather have something that would keep the AC running since it's 100 outside, but would also take something that just shut the system down to protect the compressor
 
Do you want best or do you want cheap?

Does the voltage fluctuate or is it consistently low ? How many amps? 240 or 120 volts?
 
Found something called the surge guard 30amp that is used for RVs, would this work? It would have to control my 30amp line that feeds both 16000 btu ACs.
 
Would like to have the best and cheap!! But realistically I know it's gonna cost, but so does replacement ACs. 120v 30amp is the line that feeds them, never seen spikes just low. We have complained to the marina (several people have had problems) but they say not their problem!
 
I think it stems from mostly undersized wires feeding the pedestals, it has gotten worse since more boats/liveaboards have come to the marina and at peak times like summer with all the ACs running.
 
Sounds like undervoltage which is a whole nother animal from spikes/surges.

Suppressors are relatively cheap..good marine transformers aren't.

Some have actually paid to have a new line run to their slip because it was cheaper than replacing compressors or buying a transformer.
 
I probably don't have the answer your looking for, but like others here I deeply suspect that a "cheap" solution is going to be elusive. The one caveat to that is whether you will be upgrading other electronics soon, such as your inverter.

One of the reasons I bought my Victron unit was that it can take a variety of inputs and deliver proper voltage. It essentially "reproduces" the wave form and sits between the line in and your AC panel. Since I have a 48 foot boat and only a 30 amp outlet at most of the marina's I've berthed at, it also helps be being able to handle occasional AC loads that are larger than I can get from my shore power cable. It does this by phase matching with an input source and if I'm temporarily pulling more than my 30 amps, the inverter will make up the difference. Most inverters will automatically switch between shore and inverter, but will not "make up" for a few extra amps when an AC unit or heating unit spikes as it comes on. It's one of the reasons I installed a somewhat oversized battery bank to "buffer" the average load needs.

Is this worth converting to just for these benefits. Maybe not. If you were getting close to replacing inverter/charger, then this would be a good time to consider solutions that could handle this issue at only a couple hundred more than the usual off the shelf gear.

Not all the inverter mfg's have produced phase matching or co-generating systems that will do this, Victron is one and I believe Mastervolt does as well. There are a number of isolation transformers that can handle this task, but again you are not in the couple hundred dollar category. This used to be rather rare, but as off grid systems are gaining popularity, this stuff is becoming more available.

Another creative thought, along the same lines through a different mechanism would be to look for an AC compressor that ran natively on DC. Your house batteries then become the low voltage buffer to the compressor. Battery chargers are a bit more forgiving to lower input voltages, but you would need to be capable of charging at a rate to keep up with the average AC load. That might not be my first choice, but again, its an option. Getting the line voltage up itself may not be in the cards, marina's don't upgrade wiring until they are forced kicking and screaming.
 
I would rather have something that would keep the AC running since it's 100 outside, but would also take something that just shut the system down to protect the compressor

I worked for a large school system and many of the large systems had protection that would shut them down if they were in danger of being damaged by low voltage. These systems cost a lot more than your boat's AC compressor. A lot more.

You might do some Internet research or check at an electrical supply house. It's even possible that the maker of your system sells or could recommend such a shut down device.
 
Thank you for the idea ghost, I was going to upgrade to a magnum 2812 before we leave to go down island in 4 years but was going to wait awhile. My question is I was going to have the magnum handle only a couple smaller items, wasn't even going to try running the AC off it. I just liked the big charging capabilities. Would I need 2 I/C? One to run the smaller stuff while on hook and one monster one to "condition" the voltage while still a dock queen for 4 more years? Or just use it for the AC now and rewire it when ready to cut the dock lines?
 
Do they even make an inverter charger that can handle the 30amps that it would have condition? Or does it only have to kick in that little bit to bring the voltage back up?
 
Find an electrician who can measure you voltage, evaluate your load and install a proper size buck boost transformer at your pedestal, or better yet in your boat before your panel (will need a switch so you can switch it off when you travel to places with good power. These apply a constant boost percentage, so good only in situations where the voltage is low, but fairly stable. Do you have just one 30/120 line feeding the air cons?

Does your boat have an isolation transformer? If so, on many of them you can wire in a switched circuit that will boost as well. A lot of Hatteras guys do this. I was lucky, a PO installed two Charles IsoBoost transformers in place of the OEM. This is the deluxe $olution , and was a real selling point for us.

We have a daughter who lives in NOLA, her office probably isn't far from your marina (Causeway @ the lake). We were down there a few weeks ago, I can see how'd one could get desperate.

Sounds like you could use a copy of Calder's "Boat Owners Mechanical and Electrical Manual" , and a good marine electrician.
It is very unlikely an inverter will solve the issue at hand in any practical way.
 
Last edited:
Looked at some buck booster models, looks like a possible fix as well. Calder is my bible/nightly read as every job/repair I do on this 1973 43' gulfstar trawler is the first time I have ever done it! God New Orleans is hot right now, plus I'm a night line haul driver that is trying to sleep during the hottest part of the day. Anyhoo, South Shore Harbor Marina is not going to fix anything in my lifetime, been round and round with them already, so i guess its up to me.
 
Speaking of sleep, I gotta get my butt in front of the fan and try to get some. Thanks for all the input guys, I'll check back in the morning when I get home.
 
I looked up a Victron 3600 isolation transformer that is capable of boosting low input voltage. Looks like it costs around a boat unit. Ouch. That's what it needs if you have low voltage though. Boosting and cleaning dirty power does not come cheap.
 
Thank you for the idea ghost, I was going to upgrade to a magnum 2812 before we leave to go down island in 4 years but was going to wait awhile. My question is I was going to have the magnum handle only a couple smaller items, wasn't even going to try running the AC off it. I just liked the big charging capabilities. Would I need 2 I/C? One to run the smaller stuff while on hook and one monster one to "condition" the voltage while still a dock queen for 4 more years? Or just use it for the AC now and rewire it when ready to cut the dock lines?


98% of the time I run my whole boat off a single 30 amp shore power cable and all the circuits go through the Victron unit, not just a couple circuits. It gets a bit complicated from there, but to do this safely I have automatic load shedding so if all of a sudden I am not connected to shore power my inverter does not try to generate 30-50 amps of power all by itself (which it will happily do otherwise) and become a sudden massive drain of my house batteries, overheats or both.

Victron is not the most easy company to work with, so if i were to do this again I would seriously consider other companies such as Mastervolt which I think coincidentally is another Dutch company. I had to design the load shedding as Victron did not deliver in the box what their marketing stated ( and I think maybe still states). But in any case, when you have it working its a pretty amazing system. You would want to find an electrician that is familiar with these concepts. Most of the people I talk with on the dock actually think "Oh yeah, mine does that too", probably 80% of the people I talk with on the dock would say that. Trust me, almost none of them have it. It's got to be pretty hard to sell when most of the people have no idea, including the sales people!
 
............... Anyhoo, South Shore Harbor Marina is not going to fix anything in my lifetime, been round and round with them already, so i guess its up to me.
Moving to another marina might be the least expensive solution.
 
Truly, if it were a perfect world a device would track and record low amperage conditions so the marina insurance company would be liable. Would not take many claims to force correction.
 
Truly, if it were a perfect world a device would track and record low amperage conditions so the marina insurance company would be liable. Would not take many claims to force correction.

Many, many years ago we had just such a device at work (it tracked voltage over a period of time and displayed the results on a chart). How long ago was this you ask?

Well there was a cardboard chart driven by a clock motor and a pen that moved up and down with the voltage and drew a line on the chart.

I suspect the newer models are more sophisticated than that. ;)
 
Yeah, I have seen old school. The new control panels I feel sure have those option, or they have an app for that.
 
The easy low cost solution is to find another slip at a marina that has the power you require .
 
Thank you for the idea ghost, I was going to upgrade to a magnum 2812 before we leave to go down island in 4 years but was going to wait awhile. My question is I was going to have the magnum handle only a couple smaller items, wasn't even going to try running the AC off it. I just liked the big charging capabilities. Would I need 2 I/C? One to run the smaller stuff while on hook and one monster one to "condition" the voltage while still a dock queen for 4 more years? Or just use it for the AC now and rewire it when ready to cut the dock lines?

Could you explain what you mean by going down island? If you are leaving North America for the Caribbean you have an added issue of the switch from 60 hertz to 50 hertz. The most practical solution for the hertz change is to have one inverter / charger providing the 110v 60 hertz power for the boat and the other inverter/charger accepting the 50 hertz shorepower (assuming 110volts) and charging the batteries. If you get two Magnum 2812s you can gang them and may be able to run your airconditioning off the combined output while still home.

The next set up is to add an isolation transformer ($$$) and be able to convert to the European 220 volts to North American 220volts (still 50 hertz) so that the boat can split the 220volts into North American 110volts.
 
Found something called the surge guard 30amp that is used for RVs, would this work? It would have to control my 30amp line that feeds both 16000 btu ACs.


Are the two aircons the only thing running on that single 30-amp supply?

-Chris
 
Victron is not the most easy company to work with, so if i were to do this again I would seriously consider other companies such as Mastervolt which I think coincidentally is another Dutch company.


I was looking at a marina web page the other day, and it showed Mastervolt being a Marinco company.

-Chris
 
Good morning all, just got back from work. Yes, switching marinas would be the easiest but there are only two choices in New Orleans and the other has a 3 year waiting list.
Down island is just what the Admiral and I call it when we finally leave the dock for good and journey through the islands to Grenada, from there, who knows and how long, we're just gonna play it as it comes our way!
Yes, both AC's are run off a dedicated 30amp.
I'm leaning heavily towards Ghost's idea and getting the victron or mastervolt I/C to take care off the low voltage that comes our way. I was going to get it anyway, but the AC and several unforeseen boat bucks have hit hard this month. But if I'm learning anything from all the boat repairs over the last 4 years is DO IT RIGHT THE FIRST TIME and don't friggin penny pinch when the good stuff is needed. That last one is hard for me cause I'm very frugal, or try to be living my dream of boat living and eventually long term cruising!
And to think I didn't buy a sailboat cause I thought they were too much work!!
 
Oh, great. The ancient Cruise Air split system that i've been patching and limping with has finally died too. Oh well, 30 plus years was a good run. Looks like another purchase is in the works.
 
On a side note, I read on a AC install thread about someone using insulated pvc instead of the flexible hose to get better air flow and cooling. Any thoughts before I start buying in bulk? Sounds like it would work really good, but a pain in the butt to wrap the insulation and try to maneuver through the confined spaces/cabinets.

Sorry, I should probably start a new thread
 
Last edited:
Good morning all, just got back from work. Yes, switching marinas would be the easiest but there are only two choices in New Orleans and the other has a 3 year waiting list.
Down island is just what the Admiral and I call it when we finally leave the dock for good and journey through the islands to Grenada, from there, who knows and how long, we're just gonna play it as it comes our way!
Yes, both AC's are run off a dedicated 30amp.
I'm leaning heavily towards Ghost's idea and getting the victron or mastervolt I/C to take care off the low voltage that comes our way. I was going to get it anyway, but the AC and several unforeseen boat bucks have hit hard this month. But if I'm learning anything from all the boat repairs over the last 4 years is DO IT RIGHT THE FIRST TIME and don't friggin penny pinch when the good stuff is needed. That last one is hard for me cause I'm very frugal, or try to be living my dream of boat living and eventually long term cruising!
And to think I didn't buy a sailboat cause I thought they were too much work!!

If you have two conditioners running off the same 30 amp circuit, the voltage drop may well be on your own boat. Before you invest thousands of dollars in a fix you may not need, have a qualified person check your boat's wiring as well as the shore power to determine exactly where the problem is.

I posted above about a device that records voltage over time. A good electrician would have access to one of these or you could rent one. Connect it and record the voltage for a week or so. Ideally, this would be at the pedestal but on the same circuit as your boat.
 
Back
Top Bottom