Inverter and batteries

Geoff.D

Executive Member
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Aug 4, 2005
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8,838
In the end, it is about economics - No power - no revenue generation - no income vs Backup power and income with a possible higher risk of damage, which can be mitigated against with a dose of common sense and monitoring with precautions.

What is completely unacceptable, when suppliers of UPS's and inverters DO NOT tell you up front in their blurb what type of inverters its is. Then the decision is yours. Yous should have to scratch through the fine print to find the type and any other critical factor such as the type of batteries used and the expected stby time.
 

Dairyfarmer

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Apr 17, 2016
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1,890
Got the cables all connected (knew the spark was coming but it gave me a fright anyway). Inverter powered up fine reading 25v and 2A. No load or utility in. Then the menu button wouldn't work. So GeeWiz will collect it on Monday to replace it.

So I've decided on going with a bigger backing board to hang on the wall. Found a box with a DIN rail that will house 2x2 pole isolators. So I will mound the box on the backing board. Utility in isolator will be housed there so I can isolate Eskom at the inverter. I will leave in Inverter out isolator on the main DB board.
photo_2019-02-15_14-10-27.jpg
 

RedViking

Honorary Master
Joined
Feb 23, 2012
Messages
15,150
Got the cables all connected (knew the spark was coming but it gave me a fright anyway). Inverter powered up fine reading 25v and 2A. No load or utility in. Then the menu button wouldn't work. So GeeWiz will collect it on Monday to replace it.

So I've decided on going with a bigger backing board to hang on the wall. Found a box with a DIN rail that will house 2x2 pole isolators. So I will mound the box on the backing board. Utility in isolator will be housed there so I can isolate Eskom at the inverter. I will leave in Inverter out isolator on the main DB board.
View attachment 620372
Why does it spark?
 

Chuckmyster

Executive Member
Joined
Aug 2, 2016
Messages
5,230
I've done my research are read reviews, and modified sine wave is fine. Most modern equipment is also designed to allow for modified sign wave. But this has already been debated enough in other threads.
yup as far as my knowledge goes.
only drawback is "some" modified cheap ones will produce a humming sound, sometimes you hear that in speakers. Annoying, i have a 20yr old modified inverter that does that.
the one thing i have heard that is bad about modified is running a fridge on it. Apparently the motors dont like it one bit. But this is something i havent researched properly yet
 

falcon786

Executive Member
Joined
Jan 29, 2011
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9,316
yup as far as my knowledge goes.
only drawback is "some" modified cheap ones will produce a humming sound, sometimes you hear that in speakers. Annoying, i have a 20yr old modified inverter that does that.
the one thing i have heard that is bad about modified is running a fridge on it. Apparently the motors dont like it one bit. But this is something i havent researched properly yet
Older fridge motors(and even current cheaper models) used AC motors which don't always like modified and some won't even run on it at all.

Newer tech "inverter" type fridges use DC motors with an inverter before the motor so these would be fine to run on modified sine wave as the inverter beats it somewhat into shape.]

The world is moving towards DC motors in appliances even things like aircons and fish tank pumps use DC these days so for now it's down to your actual items that you own.
 

Chuckmyster

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Joined
Aug 2, 2016
Messages
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Older fridge motors(and even current cheaper models) used AC motors which don't always like modified and some won't even run on it at all.

Newer tech "inverter" type fridges use DC motors with an inverter before the motor so these would be fine to run on modified sine wave as the inverter beats it somewhat into shape.]

The world is moving towards DC motors in appliances even things like aircons and fish tank pumps use DC these days so for now it's down to your actual items that you own.
great to know, thanx for the share :thumbsup:
 

RedViking

Honorary Master
Joined
Feb 23, 2012
Messages
15,150
Older fridge motors(and even current cheaper models) used AC motors which don't always like modified and some won't even run on it at all.

Newer tech "inverter" type fridges use DC motors with an inverter before the motor so these would be fine to run on modified sine wave as the inverter beats it somewhat into shape.]

The world is moving towards DC motors in appliances even things like aircons and fish tank pumps use DC these days so for now it's down to your actual items that you own.
How do I check this and if my fridge has an inverter before the motor? For example does this 3.5K fridge have an inverter or is it only the top range?
 

Tinuva

The Magician
Joined
Feb 10, 2005
Messages
8,326
How do I check this and if my fridge has an inverter before the motor? For example does this 3.5K fridge have an inverter or is it only the top range?
That fridge doesn't.

Easy way to tell if the fridge has an inverter, is when it has a digital temperature setting. It's not always 100% but generally.

Samsung like to advertise it as a selling point on their fridges. Bosch is my favorite choice for digital inverter fridges.

Usually in the R6000 range and up.
 

Geoff.D

Executive Member
Joined
Aug 4, 2005
Messages
8,838
Pretty much any induction motor does not like anything not pure sine wave. Remember a lab experiment back at varsity where the whole purpose of the experiment was to undertake a series of tests dealing with harmonic distortion effects on induction motors ........

Presumably, the move towards DC motors (which BTW is NOT a new idea at all) is to be able to cater for alternative sources of power availability. Remember a fridge my parents had that ran on a DC compressor suitable for use when connected directly to a battery bank ( 1950's)
 

mister

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Joined
Jul 21, 2008
Messages
6,942
If you're happy with 1000W of power then this is by far the best power trolley:

https://www.takealot.com/smart-powe...including-2x-100ah-gel-batteries/PLID41356456

I bought one a few months ago and am very happy with it. It even has a connection to connect a solar panel too if you don't want to charge from the mains.
Hey all

Been researching this and wanted to put out a warning.

"Energy Spark" are also selling this: http://www.energyspark.co.za/produc...a-1000w-pure-sine-inverter-ups-charger-solar/

The specs on their website are wrong, and the customer support chat agent has no idea what she is talking about. Turns out they are possible scammers. Energyspark is owned by the bitcoinprosper people. You can find more info here: https://mybroadband.co.za/forum/threads/bitcoinprosper-co-za-online-store-beware.939723/

The product is actually designed by http://smartpowersystems.co.za/ - and I must say, their presales communication is really good - much better than what I am used to from ZA suppliers! The inverter is made by Foshan Unipower. Only downside for me so far is that there is no automatic restart after the batteries run flat and power is restored. You have to press a button so it won't work for remote sites.
 

Geoff.D

Executive Member
Joined
Aug 4, 2005
Messages
8,838
Hey all

Been researching this and wanted to put out a warning.

"Energy Spark" are also selling this: http://www.energyspark.co.za/produc...a-1000w-pure-sine-inverter-ups-charger-solar/

The specs on their website are wrong, and the customer support chat agent has no idea what she is talking about. Turns out they are possible scammers. Energyspark is owned by the bitcoinprosper people. You can find more info here: https://mybroadband.co.za/forum/threads/bitcoinprosper-co-za-online-store-beware.939723/

The product is actually designed by http://smartpowersystems.co.za/ - and I must say, their presales communication is really good - much better than what I am used to from ZA suppliers! The inverter is made by Foshan Unipower. Only downside for me so far is that there is no automatic restart after the batteries run flat and power is restored. You have to press a button so it won't work for remote sites.
Thanks for the link. Pity their website FAQs do not appear to be there or are not working properly.
 

Dairyfarmer

Expert Member
Joined
Apr 17, 2016
Messages
1,890
Why does it spark?
The inverter internal components are taking in power even though the inverter is switched off. Think of it like your water pipes at home. If you have turned the main supply off to fix a pipe the turn it back on, you have all that air in the pipes that needs to come out.
 
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