Inverter

Thanks Ted, sorry to OP for the thread drift.

O C Diver said:

Ted,

Try:

Power Inverters and Solar Inverters for Home and Businesses - The Inverter Store

They seem to have one of the widest selections at competitive prices. Had one of my units die with in a year from something coming loose inside and shorting the inverter out. They replaced the unit promptly.



16,000 btu ac with rotary compressor and 120 VAC raw water pump. It requires about 120 amp 12 VDC. Use a 220 amp Lecee Neville truck alternator to provide power and an 8D battery to handle the starting surge.

Ted

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Thanks but they don't have 110v DC to 120v AC units

Ted

hmason...Worked great on shore power but burned out instantly when I tried it on an inverter.

Thx for posting, you likely solved a 3 yr mystery on HEY JUDE. We've burned up 2 Lasko vertical fans on our 15 yr old inverter. We have Baker's electrician installing a Magnum 2000 while he upgrades the battery leads & adds a couple of switches.

As BPoker said, you need to understand your requirements, both current and future. We went with the Magnum 2800 rather than the 2000, because of the increased charging capacity. It's been excellent. You should have the BMK kit with shunt and the Remote panel for monitoring. Magnum is highly regarded and their customer support has been excellent in my case.

Surprised no one has mentioned this but important to keep in mind inverters are most efficient (maybe even ONLY efficient) near their max power, so a lot of applications are best off having a small even just a 750W inverter to run a couple outlets you use the most (e.g. laptop) and a larger one for remaining. The specs won't normally show the efficiency curve only idle draw and peak efficiency.

Sure, run them at their maximum. My $500 pos Xantrex 1KW true sinewave puked, rolled over and died on a sudden power load slightly over 1KW operating my fridge and another load. REplaced with Chinese junk 2KW true sinewave for $175 which continues to work very well.

There are other issues pertaining to running at max power and one is cooling especially in warm climates along with being operated in areas where air circulation is poor. But getting back to efficiency. Who really cares if their "box" operates at 89 or 92% efficiency?

foggysail said:

Sure, run them at their maximum. My $500 pos Xantrex 1KW true sinewave puked, rolled over and died on a sudden power load slightly over 1KW operating my fridge and another load. REplaced with Chinese junk 2KW true sinewave for $175 which continues to work very well.

There are other issues pertaining to running at max power and one is cooling especially in warm climates along with being operated in areas where air circulation is poor. But getting back to efficiency. Who really cares if their "box" operates at 89 or 92% efficiency?

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Your chinese inverter gets 89% efficiency at 10% load? I'll take two!

kev_rm said:

Your chinese inverter gets 89% efficiency at 10% load? I'll take two!

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Who knows? I don't care what the efficiency is as long as it works reliably

But lets consider efficiency. As a circuit design engineer I designed numerous switch mode power supplies in my past. There are only a few things that drive power losses in an inverter. They include the reverse protection diode at the power input....if they even provide one. One needs to check the device's voltage drop curve as a function of current. It will also change as a function of temperature which is the same for most silicon diodes. That voltage drop times the input current.....for say a 2KW inverter will be in the 165 amp range or a power loss of 165 X (.7-1.0) or 115-165 watts. Good reason to not provide reverse polarity protection.

Been a long time since I did this stuff and power switching devices have improved a great deal over time with the advent of power mosfets. So guessing they could have in the neighborhood of .5 volts when full on. Note-- one power switch won't cut it, too much power so designers use many in parallel for switching. Next power loss will be in the switching transformers, both in the transformer wire along with core losses.

Today I imagine this stuff is now cut and paste so there might be less safety factors in the cheapies vs higher priced units. But I will further guess that there is very little difference in the efficiency. OH.... remember I mentioned that the power switches are paralleled? That could have a negative impact on efficiency if the Chinese cut the total number in parallel to save on component costs but I doubt it. Parts that used to cost big bucks when I was doing circuit design are now priced as if they were popcorn.

You can purchase a $40 shirt made in the U.S. or go to Wally World and purchase a similar shirt for $15-20. Both will serve as shirts. This is going to be a major problem for Donald. The bad thing is today you might not be able to find any shirts made here and the same goes for inverters

foggysail said:

Who knows? I don't care what the efficiency is as long as it works reliably

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"Cost is not an object" - said no professional engineer ever.

I was going to post an observation, but after reading some of these posts i got a headache realising this stuff is so above my head that I am completely out of my depth, so best not to venture an opinion.

Suffice to say.

I had a 2000W Xantrex, it died- not happy
Bought a Victron 2000W inverter/charger, it works-happy

My Victron is a much larger unit & it takes about 15 seconds to switch from inverter power to AC, during that time you must be careful not to turn on any high draw electrical load, such as a compressor, hot water element or jug, as the Victron will howl in protest, till the unit switches automativally to AC

I have been using a West Marine 4000 watt with remote switch for years with good reliability. Note you will need to replace your a.c. main 3 poison switch (off/ shore/ gen) with a 4 position swich. Expensive $600! Also use very heavy gauge wire to battery and short run.

MVDarlin said:

Note you will need to replace your a.c. main 3 poison switch (off/ shore/ gen) with a 4 position swich. Expensive $600! Also use very heavy gauge wire to battery and short run.

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Many boats are set up without a separate position for the inverter. The wiring is set up so that power from shore power or the genset is passed through the inverter to certain outlets on the boat. Typically the passthrough is not connected to the air conditioner, the water heater, or electric stove.

Bay Pelican said:

Many boats are set up without a separate position for the inverter. The wiring is set up so that power from shore power or the genset is passed through the inverter to certain outlets on the boat. Typically the passthrough is not connected to the air conditioner, the water heater, or electric stove.

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Yep, ours is this way.

Main panel has two main AC breakers, one for shorepower, one for genset. If either one or the other passes AC to inverter/charger, the unit charges batteries and current passes though to it's own specific circuits.

The inverter/charger has it's own internal automatic transfer switch, switching between charging or inverting... so if neither shorepower nor genset breakers are open, the unit inverts, enabling it's own specific circuits.

The specific circuits in question are all relatively low consumption outlets, largest consumers likely being the two separate circuits the microwave and the coffee maker are plugged into. No AC (aircon) water heater, fridges, etc...

-Chris

ranger42c said:

Yep, ours is this way.

Main panel has two main AC breakers, one for shorepower, one for genset. If either one or the other passes AC to inverter/charger, the unit charges batteries and current passes though to it's own specific circuits.

The inverter/charger has it's own internal automatic transfer switch, switching between charging or inverting... so if neither shorepower nor genset breakers are open, the unit inverts, enabling it's own specific circuits.

The specific circuits in question are all relatively low consumption outlets, largest consumers likely being the two separate circuits the microwave and the coffee maker are plugged into. No AC (aircon) water heater, fridges, etc...

-Chris

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I like to use microwave while underway with inverter sometimes. Care must be used not to switch on battery charger while using inverter. 4000 watt dedicated inverters primary use on my boat is running 5cf chest freezer while underway and refer. Freezer has super insulation. It freezes liter water bottles I use in my Pelican super coolers. I use these for perishables when on long remote cruises in the Sea of Cortez. This system works well as long as freezer can run 2 hrs a day. I have 2 alternator that generate 65 amps each while underway. I also have 4.5 kw gen set. I usually run it Ann hour am and an hour pm while at anchor to top batteries and run freezer / hot water / refer. I have a dedicated Charles 50 amp smart charger for my bank of 6 golf cart batteries for the house. Separate 8 d start battery with mechanical "off" switch on box to assure there is no unintended loss of charge. Also. Last resort is 2000 watt Honda generator.

MVDarlin said:

Care must be used not to switch on battery charger while using inverter.

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Just a friendly suggestion - Your charger should not able to source the output of an inverter.

The basic design I like best is an inverter charger combo, which takes input from utility or genset via 50A automatic transfer switch, auto switches from charge to invert when source is disconnected, and powers either a specific circuit with a few key outlets, or if big enough, feeds your whole breaker box. You have to pay attention to how neutral circuit(s) work but other than that its totally foolproof.

The only remaining puzzle is if you have solar, making sure your AC charger and your Solar Charger don't collide.

kev_rm said:

Surprised no one has mentioned this but important to keep in mind inverters are most efficient (maybe even ONLY efficient) near their max power, so a lot of applications are best off having a small even just a 750W inverter to run a couple outlets you use the most (e.g. laptop) and a larger one for remaining. The specs won't normally show the efficiency curve only idle draw and peak efficiency.

Click to expand...

We operate our boat primarily as a DC boat. I find the "background" consumption of the inverter adds up when on anchor, so we turn the inverter off unless we need to operate AC appliances. On sunny days, once the house bank is charged via the solar panels, we switch the inverter on to charge I-devices, etc, because they charge faster. Same when running. Otherwise the I-devices are charged via a DC USB port.

JDCAVE said:

We operate our boat primarily as a DC boat. I find the "background" consumption of the inverter adds up when on anchor, so we turn the inverter off unless we need to operate AC appliances. On sunny days, once the house bank is charged via the solar panels, we switch the inverter on to charge I-devices, etc, because they charge faster. Same when running. Otherwise the I-devices are charged via a DC USB port.

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I think the problem lies in when you need small amounts of A/C, like a laptop.

At 100 watts output, a 2000W inverter will have very poor efficiency. ( and I mean like < 50%)

12V USB chargers are definitely key these days and with good switching 2A outlets, they should charge just as fast as with an AC adapter..

I have two inverters, one is an old Heart design that operates as both a charger and inverter from my 24v bank. It's used as an inverter only when away from dock/genny AC. The second inverter is a 2KW true sinewave inverter that gets turned off only at the season's end. It sits running in idle mode waiting to immediately provide power in the event of an AC perturbation.

The 2KW inverter is essential for my refreigerator to operate uninterrupted. It also is used for things such as our microwave, tv and a AC lamps. And I care not about efficiency!

kev_rm said:

I think the problem lies in when you need small amounts of A/C, like a laptop.



12V USB chargers are definitely key these days and with good switching 2A outlets, they should charge just as fast as with an AC adapter..

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To reduce the inefficiency of using an inverter for charging devices I use 12 volt chargers for several different devices, IPADs, laptops, phones, hand held radios, flood lights, and flashlights. To further reduce the inefficient use of the inverter I have a 110v outlet which is powered only when the generator or shore power is on. I use this outlet as a charging station for several devices which need AC power to charge.

All I know about 240v inverters is they suck my battery's dry faster than Monica Lewinsky and forced me to buy a small Yamaha generator

I bought a Magnum MS2000-15. Thanks to all of you for your input. Does anyone know where I can a good deal on marine wiring?
Thanks so much JD

Pieyed47 said:

I bought a Magnum MS2000-15. Thanks to all of you for your input. Does anyone know where I can a good deal on marine wiring?
Thanks so much JD

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Genuinedealz.com which used to be Bestboatwire. They will also crimp lugs to your specs.

David

djmarchand said:

Genuinedealz.com which used to be Bestboatwire. They will also crimp lugs to your specs.

David

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+1

Marine Wiring, Boat Cable and Electrical Genuinedealz.com

gaston said:

All I know about 240v inverters is they suck my battery's dry faster than Monica Lewinsky and forced me to buy a small Yamaha generator

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You need better inverter or better batteries.
As a full time live aboard on the hook we currently run a
500 litre 2 door Samsung fridge freezer with icemaker
120 litre bar fridge
90 litre freezer
180 litre rheem hws
40 inch and 37 inch TV
Laptop and mini PC
Various pumps, toilets, lights, chargers for phones, tablets and eneloops
All running through a victron 5000 and 8 x 220ah 12v.
Batteries are very rarely below 80% in the morning.
On a sunny day solar has them at 100% by lunchtime Charging with as much as 120 amps.
Used the genset for 2 hours about 2 months ago.

Simi 60 said:

You need better inverter or better batteries.
As a full time live aboard on the hook we currently run a
500 litre 2 door Samsung fridge freezer with icemaker
120 litre bar fridge
90 litre freezer
180 litre rheem hws
40 inch and 37 inch TV
Laptop and mini PC
Various pumps, toilets, lights, chargers for phones, tablets and eneloops
All running through a victron 5000 and 8 x 220ah 12v.
Batteries are very rarely below 80% in the morning.
On a sunny day solar has them at 100% by lunchtime Charging with as much as 120 amps.
Used the genset for 2 hours about 2 months ago.

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Yes Semi, your's is a good post! I can relate my experience to it. Gaston's post makes one wonder if his battery bank is fully charged at the start of his inverter use. An exceptional 3 stage charger is needed to fully charge a large battery bank in short hours. I know that the Xantrex 50 ampere charger that I have is useless for rapid recharging because it enters float conditions too early. Not so though with my solar.

I only have 4 each 150 watt panels to charge my 2 each 220 AH banks. Of course the 150 watts would be meaningful only if I used an MPPT controller. Even still, my batteries see 20-24 ampere charging for hours so that at the end of the day, the batteries are again ready to take on power providing tasks.

Have to chuckle at those who think efficiency is the problem. The solution is of course batteries and battery charging. Today all switch mode inverters, even inexpensive ones, true sine and pseudo sine wave have respectable efficiencies that exceed 80%. OK, at open circuit output, all have a housekeeping load (25 watts typical for the Magnum series true sine wave inverters) which is present at 0 load to full load but that certainly is not a battery killer.

Our power consumption is less than yours but the boat is smaller. Even so we enjoy an 8.3 cuft fridge with self defrost, two 32" HDTV, two laptops, small chargers, electric toilets, pumps and the list goes on. Nice to be a power pig while at the same time keeping the environmentalists happy by restricting the generator to about 1-2 hours/day for hot water.

Just added a hardtop over the helm which will provide additional real estate for more panels. Be nice to have enough solar to heat our water.

Another vote for Magnum.

Simi 60 said:

You need better inverter or better batteries.
As a full time live aboard on the hook we currently run a
500 litre 2 door Samsung fridge freezer with icemaker
120 litre bar fridge
90 litre freezer
180 litre rheem hws
40 inch and 37 inch TV
Laptop and mini PC
Various pumps, toilets, lights, chargers for phones, tablets and eneloops
All running through a victron 5000 and 8 x 220ah 12v.
Batteries are very rarely below 80% in the morning.
On a sunny day solar has them at 100% by lunchtime Charging with as much as 120 amps.
Used the genset for 2 hours about 2 months ago.

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Simi, I've got serious solar envy! Well done, mate!

If Simi`s boat had been docked in Adelaide when South Australia recently lost all electrical power in a storm, they may have been ok.

I have 720 watts solar through an Outback Controller to 10 235 watt golf cart batteries. The 1.5 kw Samlex Pure Sine Wave Inverter, (separate from charger) is only there for the TV for future use when I have the coin for a dome. Otherwise I am a 12volt boat with 3 12v Engle refer units, 2.5 amp draw each while running. Lighting, device charging is all 12v.

Hot water, and other high AC load such as air conditioning then it is Hello Ginny! By about 10-11AM the batteries are floating up from 75% @ dawn, If needed then run the 12v watermaker (9gal an HR) till 3hrs b4 dusk. By dark I like to see a float. Gennie 9-10PM or so to shower and final float from charger before bed. Seems to work fine. I like those batteries above 70%.

Our inverter system runs 24x7 whether we are on the boat or not. Lots of our systems are AC powered, so we need/want AC available all the time. Yes, there is an overhead power consumption price to pay, but we elect to pay it for the convenience.

When shore or gen power is available, the inverters automatically pass the incoming power through to the loads, and switch into charger mode, so the power transition is seamless. We even have a couple of 240V appliances that run via the inverter too. That lets us do laundry and and use the oven while underway without having to run the generator. Those devices are a very light load for the generator, so better run off the main engine alternator when they are the only thing running.

The bottom line is that there are lots, and lots of ways to configure a boat's power system, trading off complexity vs automation, power consumption, cost, and convenience.