inverter talk

Tiahaar · Post by **Tiahaar** » Fri Apr 06, 2007 10:55 pm

So! My trusty 8 year old Coleman Powermate 2000/4000 inverter is fritzing on me and I went out and got a replacement. The Coleman has worked hard over the years (it powers stuff in my bus workshop off solar charged batteries, such as a drill press, grinder, vac, etc. etc. so I can build things off the grid in the storage lot) but last weekend the voltage started to wobble around. Put some meters on it and showed it was dropping to 75VAC and 60Hz, then flickering around at 100VAC-80Hz and restabalizing at 120VAC 60 Hz...will run lights but won't start motors anymore. SOMETHING is going out, yet to tell if its fixable with cleaning or fatal.

Anyways the Powermate had some bad points...to change the fuses inside you couldn't just open it up (I tried once), you had to slide the ends out, disconnect one circuit board and then slide the main board out. Ridiculous. Also the internal wiring was cheap looking...there were like a dozen wires with lugs on them screwed down to the DC posts leading off to obscure parts of the circuit boards.

My new one is another China import (aren't they all) made for Power Express. 2000/4000 watt rating, and comes with a remote (!) Woohoo, no more getting out in a dust storm to turn on my inverter in the bus cargo bay. More importantly this model has a bottom panel that comes off exposing all 8 fuses and internal wiring for inspection and cleaning. Of course I took the cover off to peek, found one stray wire clipping and a solder ball, and oddly the outlet grounds are not connected to anything (I'm pondering whether its an oversight and I should connect them to the inverter chassis or leave them floating...there is a ground lug to connect the chassis to the vehicle) but otherwise it looks nice. The DC inputs are actual large lugs connected to bars that are screwed to the main board, far superior to the Powermate design.

At left, my new inverter exposed

I'll install it tomorrow and see how it works, meanwhile how about the rest of you? Any inverter wisdom to share? Of course its best to use 12VDC stuff where possible to not have to convert to 120VAC and the things suck power just sitting there so I leave mine off when not needed. I have some long El-wire that only comes with 120VAC powerpacs that I run and it seems something always requires drillpress work so it gets used for that too (anybody need holes drilled on-playa stop by).

Bring on your inverter stories and tips please.

gyre · Post by **gyre** » Fri Apr 06, 2007 11:11 pm

The solar companies have some great material on the different types and grades.
They still make high grade inverters in the us and canada.
Efficiency varies drastically.
The biggest difference is in true sine wave units and variants of square wave units.
A wired in unit is usually a more industrial style made to run full time.
Look for cooling ability and design.
There are some discussion boards on these things and some are referred to as very unreliable.

Tiahaar · Post by **Tiahaar** » Fri Apr 06, 2007 11:57 pm

gyre wrote: The biggest difference is in true sine wave units and variants of square wave units.

True that! Also the biggest difference in price. I went the cheapie <150 route with the 'modified' sine (stepped square wave) unit but also don't plug in any super sensitive electronics.

gyre wrote: There are some discussion boards on these things and some are referred to as very unreliable.

Any names to name?? I hope the one I got is not among them. I've drooled over one of the high-end true-sine super efficient commercial units but ack the price.

gyre · Post by **gyre** » Sat Apr 07, 2007 12:11 am

I don't recall but some good companies bring in a low end line-too low.
For $150 you start getting into low end industrial wire in units that are us made in a power range around 1000 watts-not true sine wave.
Statpower and Powerstat I think are an example of this.
When I called the company they told me the imports are for casual users and people that think it has to be low priced.

Ambulances and lots of trucks use inverters now so you can find them used too.
I would buy an industrial used before a low end import.
I did find some in between imports now.
Fan cooled better quality but compact units with good heat sinks.
You may want to look at rf interference too.
The good wired in units are just black boxes and bigger with fans.

Used ones can get fried too, of course.
I can't remember the brand of the one I've been looking at.
Tripplite was one of them.
I found a good deal at the local electronics wholesaler.

There are a lot on ebay but you have to wade through the garbage.
There are a few basic types that I read about in the Sunelco catalog.
Some are efficient at certain ranges only.

Tiahaar · Post by **Tiahaar** » Sat Apr 07, 2007 12:24 am

Ah yes thanks Gyre good tips. Just went hunting for other board's stuff in inverters, indeed Tripp Lite is often mentioned as being really reliable. Also found a bit on why the ground on my unit might best be left floating as is:

(to quote a guy named ADMIN on the Otherpower board)
"Are you bonding your ground (bare wire) and neutral (white) wires together, for example in a standard AC breaker box? Many cheap inverters can't tolerate this! It might mention it in your manual, or it might not, or it might say it in really bad english. But I've seen the '7 days and then dead' syndrome before, and this can cause it...I had a client that replaced 2 Vector inverters before I figured it out. Un-bonding the bare and white wires means the system is running with a floating ground, but that's common on boats and RVs. The building inspector won't pass it, though. ADMIN"

gyre · Post by **gyre** » Sat Apr 07, 2007 12:34 am

Definitely look for an industrial rating.
The better companies make it clear in their catalogs.
Call and ask too.
I recommend buying from someone that makes big ones as well as small ones.
Reliability is the only thing they have to sell.
The industrial units tend to weigh a lot more, run cooler and are usually closer to a sine wave and more voltage stable.
Look at ratings and then crank power.
The differences start to jump out.
I was offered a mid grade import by a good company for about $80.
looks good for the money.
The industrial units have much better protection built in as well.
I can try to find out what I was looking at if you like.

Tiahaar · Post by **Tiahaar** » Sat Apr 07, 2007 11:27 pm

The new inverter is in, ready to power Camp Starship Palomino on the playa. Checks out OK, started my 1/3 horse drillpress fine, hope it lasts for several years at least. My batteries are under the bus on one side and the inverter underneath on the other to keep the cable run short. Very cool thing on this inverter is a phone cable that plugs in and that you run up to a control box wherever you want to mount it for handy on/off. Even comes with a wireless keyfob. Fancy fancy. The source relisted another batch (no connection to me YMMV etc etc): 2000/4000 inverter

Come to think of it for the average camp inverters may be more hassle than they are worth. If you have a quiet genset you already are getting 120VAC and if you are trying to do the economy 12V battery (maybe with solar charging) route then you want to have 12V lights and sound stuff. How many things do you need 120VAC for out there anyway? I have it for my shop tools and (ahem) an electric razor but other than that not needed. It does keep my genset off though...Hushville peeps would approve

gyre · Post by **gyre** » Sun Apr 08, 2007 12:23 am

The remote sounds handy.
Let me know if it holds up.

Most norelco razors are multivoltage and will run on 12V dc.
They offer a cord but I think the adaptation is internal.
There are battery chargers that are 12 V too.

gyre · Post by **gyre** » Mon Apr 09, 2007 4:33 pm

http://www.gaiam.com/retail/SolarLiving

These guys have some inverters.
Also some 12 volt fluorescents for those who don't want fixtures.
In daylight too.

phil · Post by **phil** » Mon Apr 09, 2007 5:01 pm

> If you have a quiet genset you already
>SNIP<

There are no quiet generators. :->

> It does keep my genset off though...Hushville peeps would approve

I'm a h'ville peeper, and I do appreciate the quiet. (I don't expect quiet, but I do appreciate it.)

I'm sorry to say that most rechargeble items expect 120VAC these days. They have small ICs that feed the battery what it wants and don't overcharge it. So you can't go directly from a 12VDC battery to a device even though it's a 12VDC device because it might damage the battery and you'd sue the manfacturer.

My electric shaver lasts the whole week, but if I bring a laptop or Giga Vu Pro Evolution or such, I need the inverter to recharge from my battery. So while I'm at it, I recharge my AAs, too.

gyre · Post by **gyre** » Mon Apr 09, 2007 5:14 pm

You lost me there with the ic problem.
Norelco adapts from 12 vdc to 240 ac through the same input.
My camera battery charger from bhphoto comes with a car input.
The duracell battery chargers are 12 vdc with an adapter.
Sadly the smart charger is ac only.
My canon chargers are ac only.

You do have to pay attention to polarity with any of these and you can get regulators if it is very sensitive like a laptop.
I know people who run as many as seven chargers at once off their car for cameras.

It is very common to make things in 12 vdc and use a separate power supply.
In asia this also takes care of the vast market off the grid.

unjonharley · Post by **unjonharley** » Mon Apr 09, 2007 9:16 pm

I'm working on as much 12v as posible..It's the easiest most known at this time..I want leave this to my kids, (7) grand kids (9) and great grand (2)..

I've worked up a stationary bike for generation of power..Seed saving, hybred gardening, waste disposal and water salvage..This among many ways of finding a storing food..

The kids are already using some of the things I have given them..The grand kids have a keen interest in this work..

Tiahaar · Post by **Tiahaar** » Mon Apr 09, 2007 9:43 pm

Yup off-grid would be the way to live. I like the pedal-powered generator : )

Fallout from my inverter crash last week...it zapped my little microwave! Stupidly I've left it plugged in even though I've used it maybe 2 dozen times in 10 years, it went in back when I was going to live in the bus. A voltage spike knocked out the smart board, everything else is OK, fuses good, and when I manually close the run relays the oven operates properly.

So phooey on the fancy digital timer/clock/cook controls, I'm putting in a spring wound 5 minute motor timer switch and a start switch on a latching relay. Make it a fully functional 'manual' microwave for when I want some hot soup late at work.

I'll put up a pic when its wired up.

phil · Post by **phil** » Mon Apr 09, 2007 9:59 pm

> Norelco adapts from 12 vdc to 240 ac through the same input.
> My camera battery charger from bhphoto comes with a car input.
> The duracell battery chargers are 12 vdc with an adapter.
> Sadly the smart charger is ac only.
> My canon chargers are ac only.

You're right! I'd forgotten my GVPE has a cigaret lighter adapter. Now I'll have to get a cigaret lighter for my battery, since I won't be charging off the van's battery.

But as you say, many devices don't have the adapter (my electric shaver, for one example). That's what I was locked in on.

unjonharley · Post by **unjonharley** » Mon Apr 09, 2007 10:00 pm

When micro waves were coming into there own, My boss got one with all the bell and whistles..A couple of years after I asked him which one I should get..He told me to get the one with the windup dial..That there was less to go bad on then..Also I would most likely only use it to warm stuff up..He was right..Then I did some taste tests and sold the micro wave in a yard sale..

This eveing I had some home made turkey pot pie a friend sent over to me..I poped it into an iron shillet, covered it with a domed cover and set the table timer for 10 min..Yumies..

unjonharley · Post by **unjonharley** » Mon Apr 09, 2007 10:15 pm

I have a small 12v battery pack..I't will rechrage from 110 or 12..This is what I use for the camera,shaver and other small stuff with a 75 watt or 150watt inverter.. It has two lighter ports..I use it for the bike sound system..I recharge in the day with two little solor panels..The panels can't keep up with the drain..So this year there wll be better panels..