[glen]

Paul,

240V appliances should not be ran through 2 inverters that can’t provide 240V. One problem is the appliance will draw mre current if the phase relationship is such that the voltage is less than 220. Your dryer, if European likely has a 220V motor. So, this is one load that may be inductive. If it wasn’t too difficult I would wire the dryer, cooktop, any other 220V appliance such they aren’t wired through the inverters.

We’re almost neighbors if you ever need another set of eyes or other help.

[needtocamp]

Interesting how Vantare does things so different. My Liberty inverter circuit only includes the following:

Refrigerator

Microwave

Coffee Maker

TV

Forward Outlets

Aft Outlets

Entertainment Center

Aux Compressor

Water Pump

[Archived]

Paul, are you sure the 220v dryer is run off both inverters? Hard to believe the converter would set it up that way without syncing the inverters. The voltage would drift between 0 and 220V. The dryer may be a 220v/110v model and just be wired to one leg in your coach.

Gerald

[Archived]

Gerald,

I believe it does run on 240 but maybe I am misreading the
inverters. The washer dryer in my coach is a stacked unit and the dryer portion
is labeled as 240/120 volt, 3 or 4 wire hook up so I believe you are correct in
that it can be wired as either 240 or 120.

The circuit breaker for the washer dryer in the main
electrical service panel is a doublewide 30-amp breaker so I assume that is a 240-volt
breaker whereas all others are ½ width, 120-volt breakers.

As I turn on the dryer, the loads passing through each
inverter jumps by 13 to 14 amps and drops by the same amount when I turn off
the dryer.

I just went out to the coach and double-checked to make sure
I am not giving bad information. I started with zero loads on each inverter. I
hit the start button on the dryer and the “Load Amps” meter on inverter #1 jumped from zero to 14 amps. Same thing on inverter #2, zero to 14 amps. Both inverters registered the same load when the dryer was running. Opening
the dryer door to shut off the dryer, the amperage went to zero on both inverters.

If I understand the Trace manual, the “Load Amps” is
amperage passing through or being supplied by the inverter. If that is the
case, then it seems to me it is wired as 240 volts, or am I missing something?

Paul

[Archived]

Interesting that you are seeing loads on both inverters. How could this be wired?

Assuming the dryer motor and the internal display/control unit use only 120V (i.e. are only on one inverter) and the heating element has a center tap, one could put both neutrals/shared neutral on the center tap and the hot wires from each inverter on the end terminals. While the voltage between the two hot wires would fluctuate with the AC phases, each part of the heating coil would see 120V and that is all it cares about. The shared neutral wire could see twice the current whereas in a true 240V dryer installation, there would be no current in the neutral wire. This setup would also work when you are on shore or generator power.

The other option is that the two inverters are indeed set up to be in phase (coupled) and produce true 240V.

You could measure the AC voltage between the hot wires of the inverters. If you see stable 240V +/- 5% as you change loads on both inverters, you have a bonafide 240V setup. If not, you have a custom dryer hook up along the lines above.

Of course, running the dryer off the house batteries is not practical. If you see a 14A per inverter AC load, you are pulling about a 150A DC load assuming the inverters are 90% efficient.

Gerald

[Bob]

Here’s a good summary of the features of a 4024 Inverter. It will sync the phases.

http://www.oksolar.com/inverters/trace.htm

[Archived]

The Trace units will sync to incoming commercial power to augment commercial power. Paul said he doesn’t have units that are synced with each other to produce 240V. I believe he knows this because the dryer doesn’t wirk on inverters.

The dryer likely has a 240V heating element and 120V controls. This would explain the current display on both inverters. I assume the display is showing current being drawn while on commercial power.

Does snyone really need the cooktop and dryer to be powered by the house batteries? This is one thing I don’t care for that it appears from this post and others thst Vantare did. This forces the owner to manually do unecessary load management while on inverter power. what happens when you are cooking or outside with s load of clothes in the dryer when the commercial power goes out? If, by chance, there’s enough phase difference on the inverter supplied power the inverter’s main breaker will trip or the batteries will quickly be depleted.

[Brian]

Most will agree we do not run our generators enough. Look at some entertainer buses with high generator hours which I think really shows what these generators can do and they are not fuel hogs.

I don’t see any reason to run an electric cook top or dryer just to see if the battery system will manage it.

Careful management of electric loads on either leg is important. Taking a chance pushing the extreme limits of your inverters with the risk of destroying a perfect working system.

Just my opinion.

[Archived]

I went through all the wiring diagrams for the coach and
unfortunately there is not a specific one for the washer/dryer so no answer
there.

I did confirm today that the washer/dryer breaker is in fact
a 240-volt breaker but cannot confirm they used both legs of the breaker. I
would need to pull the cover off the main service box and that is not going to
happen. Too much work just to satisfy my curiosity.

At this point, I am happy with the setup, everything works
and I do like Vantare’s electrical design and decision to run everything
through the inverters. I am no electrical expert but in my humble opinion, I think they made an
intelligent choice.

One feature of the Trace inverters is they will not let bad
power into the coach. The inverter constantly samples the voltage and frequency
of the commercial or genset power supply and unless the power meets the default
requirement set by Trace or altered by the user through the menus, the inverter
will not synchronize and let that bad power through. Additionally, the inverter will disconnect from shore power
or genset anytime the parameters are exceeded and switch to inverting mode.

While I agree, there is no logic to running a cook top or
washer/dryer off the inverter and batteries, there is reasonable logic to use
the filtering capacity built into the inverters to help protect our electrical
“stuff” from bad power.

Running all the electrical loads through the inverters allows
switching of power sources without shutting off devices. I know many people
advocate shutting off A/C units and other devices before switching from genset
to shore power but with Vantare’s approach, that is not needed. Again, this
only my opinion.

While I have no intention of using high amperage draw items
while on inverters, the electrical gods sometimes interrupt shore power at the
least opportune times. I don’t have the specs in front of me for the MC
software but I think each inverter is rated around 30 to 31 amps continuous and
up to 60 amps surge. Should the shore power be interrupted, the inverters could
in theory supply more amperage into my distribution panel than I could ever
use. Yes, the batteries would be depleted somewhat but the inverters would
start the genset bringing that power source on line to replace the failed shore
power. I already had the opportunity to test the auto-start feature when a
power pedestal breaker tripped. It was a little unnerving to leave the coach,
come back a short while later and the genset was running. The good news was the
coach was still nice and cool.

Paul

[Archived]

Paul,

I doubt this statement to be true.

“Running all the electrical loads through the inverters allows switching of power sources without shutting off devices. I know many people advocate shutting off A/C units and other devices before switching from genset to shore power but with Vantare’s approach, that is not needed.”

Your Trace inverters can not produce the same current capacity as shore or generator power. If everything runs through the inverter and your current draw exceeds the inverter’s capacity, what happens when the inverters assume the load? I could dig into the Trace manual, but as other Vantare users have said, they must manage loads while on inverter power.

FWIW, I would not use an inverter as a power protection device. We live in the lightning capital of the US. Do you really want to destroy two inverters when you could have destroyed a far less expensive external device purpose built for protection?

[Jerry]

Gil,

It is perfectly fine to doubt any statement(s) I say. I do
not claim to be an electrical expert in any way shape or form.

My best answers to your questions/comments are each inverter
can produce up to at least 50 amps for short periods of time. I have the
standard residential Trace SW 4024 manual in front of me and that version can
produce 33 amps continuous and 78 amps intermittent. The only difference between the SW 4024 and the SW 4024
MC2 (The MC2 versions are
installed in our coaches) is some software changes installed on a ROM chip.
Physically, the two units are identical. One of the software changes is a
reduction of the pass through amperage of the inverter. The pass through amperage
of the residential unit is 60 amps while the MC2 version is 50 amps. I don’t know for sure but I think the continuous and intermiittent ratings were reduced as well. If anyone
is interested, the other changes are a defeat of the “sell back” feature,
labeling for marine and RV use and a change in priority of utility (shore
power) AC IN and genset AC IN. If both utility power and genset power is
available at the same time, the residential version will connect to utility
power and ignore the genset. The MC2 version will connect with genset and
ignore the utility power.

I am not sure if I entirely agree with your statement of
“the inverters cannot produce the same current as shore power or genset power”. My understanding is the inverters can
produce the same current as shore power for short periods of time but I could
be mistaken. I don’t have the MC2 manual with me so I can’t confirm. You are absolutely
correct that the genset can produce more current than either shore power or the
inverters.

I would respectfully suggest everyone has to manage the
loads when on inverter only mode. As
to Vantare owners having to manage loads more than others, I cannot speak to
that other than to say, now that I have my battery charging conflict sorted
out, I had no issues with managing loads this past weekend under fairly heavy
usage.

You are also correct about the lightening protection aspect
and I did not mean to imply that the inverters should substitute for external
lightening protection.

The intent of that statement was protection from the
sometimes-questionable shore power at resorts and campgrounds. Having lived in
the Bahamas for a number of years, we experienced every variation of over
voltage, under voltage, variable frequency of Hz, loss of one leg or the other,
loss of neutral you can think of. The entire house with exception of the hot
water heater, clothes dryer and the central HVAC system ran through a single residential SW 4024. While people all around us were carting their
refrigerators, TVs, freezers, microwaves, etc off to the dump on a regular
basis, I sat there for many years with not a single power related failure. I
did take one TV to the dump but that was a result of too many gin and tonics at
a party. I set the parameters of the inverter a lot tighter than the Trace
defaults so it would drop the commercial power and switch to inverting sooner.
The inverter was tied to auto-start the generator just as our coaches are.

The point I wish to make (and this is only my experience) is
that in the Bahamian summer months, the inverter would kick in and out
sometimes 5-6 times a day because of fluctuating power. The refrigerator
compressor was “protected” so to speak because it never saw the fluctuating
voltage and didn’t suffer the stop/start that you might get with utility power.

I am all too familiar with living in the lightening capital
of the USA. A boat I owned sustained $70K worth of electrical damage in 1997
from lightening strike that also back-fed the house and took out a number of
appliances and even an underground phone line. On an inverter/lightening
related topic, the person that purchased my last boat emailed me a week or so
ago stating that the boat was hit by lightening. The interesting point is all
the equipment powered through the inverter, TVs, refrigerator, microwave, fresh
water pump, etc all survived whereas other items such as the A/C units did not.
Turns out, the 120-volt pass through relay of the inverter shorted out and
protected all the loads.

Gil, maybe we should get together over a beer and debate the
finer points of inverters.

Paul

[Lizzy]

Paul,

My point was what would happen if you left the coach on one of those scorching hot days to walk down to the beach. You left the 3 or 4 air conditioners going and you leave the lights on knowing you’ll likely return after dark. The refrigerator is on, the crock pot is on so you can enjoy a great pulled pork dinner when you return. For whatever reason shore power is lost and the inverters kick in. At least one of inverters if you have 2 airs, both inverters if you have 4 airs, will probably have a constant load that exceeds the inverters capacity. I’m just sayin’…

I second the idea of a cold beer. In fact, I’ll go get one now and look forward to sharing one with you later. As a former boater, mainly trawlers (not the fishing type), we can talk boats and electrons–what fun.

[Ed]

Paul/Gil:

Just FYI, that is 78 AMP RMS (not peak) and can only be sustained by the inverter for around 20 seconds before it must reduce below 60 amps.

The inverter rating is:

Continuous duty 30 AMPS, total 60 AMPS max

The inverter when in inverter mode can only supply ~33 AMPS at 120VAC, and when in pass-thru mode can supply up to an additional 30 AMPS to shore power, but not more than 60 AMPS total (shore power + inverter suppliment).

How long the inverter can sustain the 60 AMPS pass-thru/suppliment is temp limited, as well as battery voltage limited. When the batteries drop below 22volts the inverter can no longer sustain its rated 4000 watts. Keep in mind this 60AMP rating is the pass-thru/supplimental current rating, not the inverted rating (which is ~33 AMPS at 120VAC).

So if you left your coach with more than 30 AMPS per inverter leg running and lost shore power, if the genny does not get started then the inverter 35 amp breaker is going to pop as it cant support more than 33 amps without shore power.

[Wayne]

Are you sure your Dryer is 240v? Vantare usually put in a 120v Whirlpool unit, mounted as separate units, but still 120v. The few times they “gave in” to customer request, they put either a manual or automatic transfer switch and breaker in the Gen radiator bay on the wall (or bay 2 on a few I’ve seen as well) to power just the 240v dryer unit from shore or gen directly, completely bypassing the inverters.

If someone else retro-fitted a 240v dryer into the coach, they would have also had to modify the generator as well. When Vantare installed all 120v appliances, they also wired the generator to produce 120v each leg, but not out-of-phase between the two legs (look in your Power Tech manual and you will see the wiring diagrams for the two different generator output configurations). That approach ensured more balanced output between the two sets of windings on the generator even in unbalanced load applications, but of course would not support 240v loads.

[Corey]

I confess that my pea brain can’t understand all of what is being discussed in this thread and I’m sorry to interrupt this erudite conversation, but did anyone else notice that Paul’s boat or former boat was struck by lightning TWICE? Considering the natural law that has already been broken, does that mean that it is a good idea to stand near Paul during a thunderstorm, or a bad one? Ok, back to the inverters…