Inverter Installation

[chrisbaker1981]

HI, So many years ago i hooked up a lithium Iron battery to a mecer 1200VA inverter.

I used a Blue Nova 13V572Wh , just for routers and laptop. Its worked fine.

My questions are

Im moving to a new flat, and im not sure the order on disconnecting the battery, is it negative first from the battery and then negative from the inverter, and then positive from the battery and last positive from the inverter.

When i hook it up again is it in reverse, positive inverter to positive batt, neg on inverter to negative on batt?

And finally do i need to install a breaker? I havent on this setup..



Products are

Inverter - https://www.takealot.com/mecer-1200...rter-with-lcd-display-without-ba/PLID71641275

Battery - https://diygeek.co.za/product/blue-nova-lifepo4-bn13v-44-570whlithium-iron-phosphate-battery/

 

[TheChamp]

Switch off the power going to the inverter, (Eskom), switch off the inverter on the inverter power switch, disconnect the battery terminals, doesn't really matter which terminal but as a good practice, always start with the negative when disconnecting.

After that, disconnect the AC power going to the inverter, the inverter will now only have battery cable, take it as is, roll the cables for easy connection at your new place.

When you arrive at your new place, make sure the power switch on the inverter is still off, again it doesn't matter which terminal you connect first but as good practice, always connect the positive side first, remember, disconnection, the negative first, connection, the positive first.

There will be a smallernyana spark as the inverter could wake up if your battery doesn't have a switch, it's normal, proceed to connect the battery, all the while keeping the inverter off as well as the AC supply.

After the battery connection, connect the AC input cable, give everything one last check, polarities, tightness of terminals etc, both on the battery and inverter, then switch on.

 

[wingnut771]

Switch off the power going to the inverter, (Eskom), switch off the inverter on the inverter power switch, disconnect the battery terminals, doesn't really matter which terminal but as a good practice, always start with the negative when disconnecting.

After that, disconnect the AC power going to the inverter, the inverter will now only have battery cable, take it as is, roll the cables for easy connection at your new place.

When you arrive at your new place, make sure the power switch on the inverter is still off, again it doesn't matter which terminal you connect first but as good practice, always connect the positive side first, remember, disconnection, the negative first, connection, the positive first.

There will be a smallernyana spark as the inverter could wake up if your battery doesn't have a switch, it's normal, proceed to connect the battery, all the while keeping the inverter off as well as the AC supply.

After the battery connection, connect the AC input cable, give everything one last check, polarities etc, both on the battery and inverter, then switch on.

Regarding the spark, I would keep terminal screw in and touch lug to screw top so that spark doesn't damage terminal surface while charging inverter capacitors, then remove screw and attach normally.

 

[TheChamp]

Regarding the spark, I would keep terminal screw in and touch lug to screw top so that spark doesn't damage terminal surface while charging inverter capacitors, then remove screw and attach normally.

100%, that's what I do, a slight tap to discharge and then connect normally.

 

[chrisbaker1981]

OK thanks for the comments, sounds straightforward and a little scary

 

[wingnut771]

OK thanks for the comments, sounds straightforward and a little scary

You only get a fright if you're not prepared. Protect the eyes and give it a few taps and you'll be fine.

 

[denmendez65]

You only get a fright if you're not prepared. Protect the eyes and give it a few taps and you'll be fine.

Or be a cowboy like some of us. So used to zapping myself and sparks you wind up not caring. Can't kill you on the battery side especially. Voltage is tiny.

I redid most of the wiring in my DB with the inverters on supplying the house as normal. I don't recommend but it's not the end of the world if you have to lol.

 

[wingnut771]

Or be a cowboy like some of us. So used to zapping myself and sparks you wind up not caring. Can't kill you on the battery side especially. Voltage is tiny.

I redid most of the wiring in my DB with the inverters on supplying the house as normal. I don't recommend but it's not the end of the world if you have to lol.

I take it you haven't done any bush welding with 800 CCA before where the metal turns molten instantly? Dont have to worry about such things with LFP (BMS) but that initial spark has got enough amps to do a little welding.

 

[denmendez65]

I take it you haven't done any bush welding with 800 CCA before where the metal turns molten instantly? Dont have to worry about such things with LFP (BMS) but that initial spark has got enough amps to do a little welding.

I welded my screwdriver once. It's as Champ says though its due to load when reconnecting. The inverter is a load to the battery so thats why the little sparking. That wont weld anything. If he puts a DC breaker (I would) then there would be zero sparks ever.

I have dismantled and put back together the 10 batteries on the inverter probably 5 times now and have never gotten a spark. Coz the DC breaker is in between the busbars and the inverter so there is no load. If he wants zero sparks, then put a breaker. Wiring the breaker to the 2 cables will have no sparks. When changing batteries, just turn the breaker off and zero sparks again on the battery side.

AC side the sparks arent much as I was doing my work when the load was just a TV and a few lights. Oven or something would cause big kak with sparks

 

[wingnut771]

I welded my screwdriver once. It's as Champ says though its due to load when reconnecting. The inverter is a load to the battery so thats why the little sparking. That wont weld anything. If he puts a DC breaker (I would) then there would be zero sparks ever.

I have dismantled and put back together the 10 batteries on the inverter probably 5 times now and have never gotten a spark. Coz the DC breaker is in between the busbars and the inverter so there is no load. If he wants zero sparks, then put a breaker. Wiring the breaker to the 2 cables will have no sparks. When changing batteries, just turn the breaker off and zero sparks again on the battery side.

AC side the sparks arent much as I was doing my work when the load was just a TV and a few lights. Oven or something would cause big kak with sparks

We are men here, we don't use breakers or fuses.

 

[chrisbaker1981]

We are men here, we don't use breakers or fuses.

So tell me, i dont have any breaker installed on my setup, product links in the original post at the top.. Do i need to? As far as i know this inverter already has some kind of built in protections against over charge etc. The battery has its own built in BMS thingy, and i think this inverter has an over discharge safety shutoff anyway? So do i need a breaker? I just have the mains going directly into the inverter and then the battery hooked up directly to the inverter. I suppose i should get an electrician to check it out especially since im renting my flat so for insurance claims etc. I figured good quality lithium iron battery should be safe enough to not bother with compliance certificates etc. I switch everything off at night and when im out anyway so

 

[wingnut771]

So tell me, i dont have any breaker installed on my setup, product links in the original post at the top.. Do i need to? As far as i know this inverter already has some kind of built in protections against over charge etc. The battery has its own built in BMS thingy, and i think this inverter has an over discharge safety shutoff anyway? So do i need a breaker? I just have the mains going directly into the inverter and then the battery hooked up directly to the inverter. I suppose i should get an electrician to check it out especially since im renting my flat so for insurance claims etc. I figured good quality lithium iron battery should be safe enough to not bother with compliance certificates etc. I switch everything off at night and when im out anyway so

I have 2 x 100Ah paralleled together with no breaker or fuses, blocking the exit, so you're asking the wrong person.

 

[wingnut771]

So tell me, i dont have any breaker installed on my setup, product links in the original post at the top.. Do i need to? As far as i know this inverter already has some kind of built in protections against over charge etc. The battery has its own built in BMS thingy, and i think this inverter has an over discharge safety shutoff anyway? So do i need a breaker? I just have the mains going directly into the inverter and then the battery hooked up directly to the inverter. I suppose i should get an electrician to check it out especially since im renting my flat so for insurance claims etc. I figured good quality lithium iron battery should be safe enough to not bother with compliance certificates etc. I switch everything off at night and when im out anyway so

On a serious note, a breaker is just an extra layer of safety incase bms/battery or inverter go faulty. If you do install one, make sure its rated for DC with a 50A-100A (1200/13V) rated for 10kVA:




You will have to add extra cabling (sized correctly and of good quality) and connections which need to be done (crimped) right too or else they can also be points of failure.

 

[denmendez65]

So tell me, i dont have any breaker installed on my setup, product links in the original post at the top.. Do i need to? As far as i know this inverter already has some kind of built in protections against over charge etc. The battery has its own built in BMS thingy, and i think this inverter has an over discharge safety shutoff anyway? So do i need a breaker? I just have the mains going directly into the inverter and then the battery hooked up directly to the inverter. I suppose i should get an electrician to check it out especially since im renting my flat so for insurance claims etc. I figured good quality lithium iron battery should be safe enough to not bother with compliance certificates etc. I switch everything off at night and when im out anyway so

Every solar install has fusing and or breaker between the battery and inverter. Even if not solar, its a safety thing even though almost every solar system has an inverter and battery with BMS and smart inverters. I personally would put one.

Purpose is failure in the inverter or BMS and primarily for isolation to do exactly the things you are worried about with the sparking etc. If there is a problem, how do you isolate the battery from inverter in emergency? Look for spanners and start undoing? Vs just pulling a breaker.

Doubt insurance would check or care but if a fire started coz of your little inverter battery thing I wouldn't put it past them to start fishing for reasons not to pay out and blame that. But the chances of this happening are very slim, just put a breaker as Wingnut says to cover yourself for the 5% chance your BMS or inverter fails.

 

[wingnut771]

Every solar install has fusing and or breaker between the battery and inverter. Even if not solar, its a safety thing even though almost every solar system has an inverter and battery with BMS and smart inverters. I personally would put one.

Purpose is failure in the inverter or BMS and primarily for isolation to do exactly the things you are worried about with the sparking etc. If there is a problem, how do you isolate the battery from inverter in emergency? Look for spanners and start undoing? Vs just pulling a breaker.

Doubt insurance would check or care but if a fire started coz of your little inverter battery thing I wouldn't put it past them to start fishing for reasons not to pay out and blame that. But the chances of this happening are very slim, just put a breaker as Wingnut says to cover yourself for the 5% chance your BMS or inverter fails.

5%? More like 0.000000000000000000000001%.


These things never came with such luxuries:

 

[denmendez65]

5%? More like 0.000000000000000000000001%.
View attachment 1931370

These things never came with such luxuries:
View attachment 1931371

Well you can buy a floating neutral generator and if your house burns down insurance wont pay out. Just coz you can buy something doesnt make it okay.

But I am being dramatic. Main problem is Mecer and all these portable trolley things use their own batteries and come from factory sealed. Now Mr random guy goes and puts his own batteries. Is he a certified Mecer installer or electrician? Did he take it to the shop for a "professional" to put their "approved" batteries. No. So you see where I am going.

Up until you opened the unit, insurance and the inverter trolley company was liable. After that its on you.

 

[wingnut771]

Well you can buy a floating neutral generator and if your house burns down insurance wont pay out. Just coz you can buy something doesnt make it okay.

But I am being dramatic. Main problem is Mecer and all these portable trolley things use their own batteries and come from factory sealed. Now Mr random guy goes and puts his own batteries. Is he a certified Mecer installer or electrician? Did he take it to the shop for a "professional" to put their "approved" batteries. No. So you see where I am going.

Up until you opened the unit, insurance and the inverter trolley company was liable. After that its on you.

Just tell insurance you found it like that.

 

[denmendez65]

Just tell insurance you found it like that.

Lol, I cant find the Powerforum guy that got into problems coz his DB and ceiling burnt coz of a generator. He got a registered electrician to install it and got a COC. It was those floating neutral types. Insurance told him its not allowed and he sat with the almost 100k bill.

He was told to take it up with the electrician but I am sure the electrician said he just followed what the home owner wanted. Ultimately the electrician and the insurance company used the law on him.



I am being dramatic though as mentioned. Just be careful with all these DIY things. I personally went above and beyond to cover every angle I could find including adding stuff I did from work to ensure safety and compliance.

 

[wingnut771]

Lol, I cant find the Powerforum guy that got into problems coz his DB and ceiling burnt coz of a generator. He got a registered electrician to install it and got a COC. It was those floating neutral types. Insurance told him its not allowed and he sat with the almost 100k bill.

He was told to take it up with the electrician but I am sure the electrician said he just followed what the home owner wanted. Ultimately the electrician and the insurance company used the law on him.

View attachment 1931374

I am being dramatic though as mentioned. Just be careful with all these DIY things. I personally went above and beyond to cover every angle I could find including adding stuff I did from work to ensure safety and compliance.

Well, this is not connected to the DB, just a long extension cord that you might break a leg if tripping over because you have it in the pother room because the fan is too loud. Talking about fans, make sure this mecer is set to 10A and install an extra 12V pc fan when using an LFP as sometimes if still thinks the battery is full (LFP has higher resting voltage than LA) after using it so goes staright to float mode with no fan but is actually not floating but charging at 10A and will get hot. 20A will get too hot and fry itself.

 

[denmendez65]

Well, this is not connected to the DB, just a long extension cord that you might break a leg if tripping over because you have it in the pother room because the fan is too loud. Talking about fans, make sure this mecer is set to 10A and install an extra 12V pc fan when using an LFP as sometimes if still thinks the battery is full (LFP has higher resting voltage than LA) after using it so goes staright to float mode with no fan but is actually not floating but charging at 10A and will get hot. 20A will get too hot and fry itself.