Inverter circuit breaker/fuse?

RJJ

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Hi all

Duffer questions alert! The inverter stopped working a few days ago. I don't know if it's related, but it was a very sunny day - the batteries were fully charged and the solar panels were chucking it out at full whammy.

It's been working well for the three years since we bought the boat. So now the inverter red light and warning beeper sounds when I power it up, and no power comes out. Wiring to and from the inverter seem to be fine.

Pics attached. I don't know if anyone can identify the kit.

Is it likely the inverter couldn't tolerate the "more than 12v" on the house circuit? Should I look for a circuit breaker in the inverter itself? Or should I assume I've fried it and needs replacement...if the latter, should I do anything to safeguard the input voltage parameter?

Thanks in advance.
 

William_H

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I think it unlikely that the inverter can not tolerate the fully charged battery voltage. The light and beeper sounding indicates some voltage is getting to the inverter.
Inverters have a few inter locks to guard against problems. I suggest measure the voltage at the inverter input. Low voltage due to wiring too light for the load or bad switch or fuse is the most common problem with inverters. Try a wire connection from Battery positive directly to inverter. Like wise the negative battery to inverter. Do make sure that any AC load is disconnected. Possibly a load it can not handle or even a short in AC loads.
If all this fails to find problem you may have a bad inverter. Yes it may have internal fuse or failed switching transistors. ol'will
 

coopec

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I think it unlikely that the inverter can not tolerate the fully charged battery voltage. The light and beeper sounding indicates some voltage is getting to the inverter.
Inverters have a few inter locks to guard against problems. I suggest measure the voltage at the inverter input. Low voltage due to wiring too light for the load or bad switch or fuse is the most common problem with inverters. Try a wire connection from Battery positive directly to inverter. Like wise the negative battery to inverter. Do make sure that any AC load is disconnected. Possibly a load it can not handle or even a short in AC loads.
If all this fails to find problem you may have a bad inverter. Yes it may have internal fuse or failed switching transistors. ol'will

Thanks for that William! I have virtually the same problem and I'm just about to get up in the yacht and sort it out.

I was using the Ozito wet/dry vacuum cleaner when the fan on the inverter started up and then the inverter stopped ...dead. I'm wondering if some of my wiring is a bit light?

Reading the specifications of the GIANDEL 3000/6000W pure sine wave inverter they seem to be well protected electronically
 

PaulRainbow

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Thanks for that William! I have virtually the same problem and I'm just about to get up in the yacht and sort it out.

I was using the Ozito wet/dry vacuum cleaner when the fan on the inverter started up and then the inverter stopped ...dead. I'm wondering if some of my wiring is a bit light?

Reading the specifications of the GIANDEL 3000/6000W pure sine wave inverter they seem to be well protected electronically

What size cables and how long ?
 

coopec

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What size cables and how long ?
Paul
Good question! (The cables from the battery to the inverter are only half a meter)
I did considered cabling size carefully but I think I may have stuffed up - maybe a crook terminal.
Everything worked fine for 6 weeks or so but it wouldn't have had a heavy load until I used the vacuum cleaner.

Installing solar panels and inverters is all new ground for me.
 

KompetentKrew

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I think one would have to know the model of inverter to properly diagnose OP's problem - how many "red lights" does the inverter have? how are they labelled? Some devices with only a single warning light flash it in different ways to indicate different types of problems.

However my contribution is to say that I recently fixed an inverter problem by replacing the main 12v (100A) fuse and its holder. This was far cheaper than I expected.

I think my inverter was successfully powering low-current devices, such as the wall wart for charging a handheld radio, but a red light labelled "low battery" would come on, and the inverter would shut off, when any real load was put upon it.

Mine is a Victron Atlas Combi 12/800 combined inverter-charger (I'd guess this model at least a dozen years old, if not 20) and it is connected to the main battery bank with some very thick cables - the thickness of jumper cables. Between the combi and the batteries, on the positive cable, is this big 100A fuse and I figure there must have been corrosion on the blades of the fuse holder (I tried sandpapering the fuse blades shiny, but that make no difference) which was causing resistance - in effect the corrosion was causing the thick cable to appear like a much thinner one. The voltage arriving at the inverter was lower than that at the batteries, causing the inverter to think the batteries were at a dangerously low state of charge. Having replaced the main fuse I can now run my dehumidifier off the inverter, and am very happy (I need to test the breakmaker next!).
 

PaulRainbow

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Hi all

Duffer questions alert! The inverter stopped working a few days ago. I don't know if it's related, but it was a very sunny day - the batteries were fully charged and the solar panels were chucking it out at full whammy.

It's been working well for the three years since we bought the boat. So now the inverter red light and warning beeper sounds when I power it up, and no power comes out. Wiring to and from the inverter seem to be fine.

Pics attached. I don't know if anyone can identify the kit.

Is it likely the inverter couldn't tolerate the "more than 12v" on the house circuit? Should I look for a circuit breaker in the inverter itself? Or should I assume I've fried it and needs replacement...if the latter, should I do anything to safeguard the input voltage parameter?

Thanks in advance.

A 12v inverter will have an input range that would cover fully charged batteries, for instance, 12v Victron Multis have a range of 9.5v to 17v

There are no attached pictures and no clues to the make or model of inverter, which makes it difficult to offer a solution, other than to make absolutely certain the connections are all 100% sound. Check the DC voltage at the inverter, then turn a load on and see what it is. Disconnect the AC output and see if it makes a difference.
 
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PaulRainbow

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Paul
Good question! (The cables from the battery to the inverter are only half a meter)
I did considered cabling size carefully but I think I may have stuffed up - maybe a crook terminal.
Everything worked fine for 6 weeks or so but it wouldn't have had a heavy load until I used the vacuum cleaner.

Installing solar panels and inverters is all new ground for me.

A 3000w/6000w inverter will be rated at 3000w continuous and 6000w for a short time (typically allowing for current inrush without causing a fault).

Rule of thumb for inverters is to divide the output Watts by 10 to give an indication of the DC input current draw. So, at 3000w an inverter will draw 300a. Use the inverter to power something with an electric motor, where current inrush could be 2-3 times greater than the stated amperage, and you could potentially draw up to 600a from the batteries.

As an example, Victron state a 400a fuse and 90mm cable for the 3k Phoenix inverter., where the cables are less than 5m. 5-10m the cables go up to 120mm.
 

Alex_Blackwood

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A 12v inverter will have an input range that would cover fully charged batteries, for instance, 12v Victron Multis have a range of 9.5v to 17v

There are no attached pictures and no clues to the make or model of inverter, which makes it difficult to offer a solution, other than to make absolutely certain the connections are all 100% sound. Check the DC voltage at the inverter, then turn a load on and see what it is. Disconnect the AC output and see if it makes a difference.
Maybe wrong but I don't think anyone has mentioned overload reset. Possibly should be automatic, maybe manual. We don't know the wattage of the vacuum or how long he was using it for!
 

coopec

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A 3000w/6000w inverter will be rated at 3000w continuous and 6000w for a short time (typically allowing for current inrush without causing a fault).

Rule of thumb for inverters is to divide the output Watts by 10 to give an indication of the DC input current draw. So, at 3000w an inverter will draw 300a. Use the inverter to power something with an electric motor, where current inrush could be 2-3 times greater than the stated amperage, and you could potentially draw up to 600a from the batteries.

As an example, Victron state a 400a fuse and 90mm cable for the 3k Phoenix inverter., where the cables are less than 5m. 5-10m the cables go up to 120mm.

SUCCESS! I've just fixed the inverter AND the solar panel charging system (the faults were related.)

I traced the fault to a 1/2/Both switch which I had installed to allow me to draw from Battery Bank 1 or 2 or both.
QUESTION Is that switch of much use i.e. practical value?

I had the 1/2/Both switch installed to draw from Battery Bank 1. I notice the plastic around the (inside) "Battery1" terminal was melted. I then made my House bank "Battery 2" and away it went! The inverter was working and the solar panels started charging.

I thought the 1/2/Both switch could take a decent current. When the inverter stopped working I was using a 1100W wet/dry Ozito Vacuum Cleaner. My electrical system is 24V so that means the vacuum cleaner would draw 1100/24 = 46A. [In line with your advice?] Because it has an electric motor I multiply that by 3 to get 138A. I would have thought the switch I have would have handled that. My switch is similar to the TMC switch (pictured). My switch is a reputable brand i.e. not a cheap Chinese unbranded bit of rubbish

(NOTE : I got my vacuum from the rubbish dump but it seems to go very well but I was sucking water. Did I short something out?)

Specifications:
  • Voltage rating: 6v up to 32v​
  • Rated at 175A Continuous duty at 12V and 300A at intermittent use.​
342401.jpg

I went for a 3000W Inverter because I want to be able to use an induction hob (2000W), microwave 1500W, bread maker etc (but not at the same time).

I do have a suitcase 3000W inverter generator which hopefully I can fit in a self draining locker (otherwise I'll have to mount on deck in a locker near the transom)
 
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PaulRainbow

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SUCCESS! I've just fixed the inverter AND the solar panel charging system (the faults were related.)

I traced the fault to a 1/2/Both switch which I had installed to allow me to draw from Battery Bank 1 or 2 or both.
QUESTION Is that switch of much use i.e. practical value?


Personally, i'd leave the switch out and use both banks at the same time. Less to go wrong ,the batteries will get an easier life because you will deplete them less, plus they will charge faster.

I thought the 1/2/Both switch could take a decent current. When the inverter stopped working I was using a 1100W wet/dry Ozito Vacuum Cleaner. My electrical system is 24V so that means the vacuum cleaner would draw 1100/24 = 46A. [In line with your advice?] Because it has an electric motor I multiply that by 3 to get 138A.

Your vacuum cleaner will draw 1100 watts at 240v, that doesn't directly translate to 1100 watts at 24VDC, there's no allowance for inefficiencies. What i said was, divide the AC watts by 10 to get DC amps, assuming a 12V system. For a 24V system, divide by 5. 1100/20 = 55A[/quote]

I would have thought the switch I have would have handled that. My switch is similar to the TMC switch (pictured). My switch is a reputable brand i.e. not a cheap Chinese unbranded bit of rubbish

Specifications:
  • Voltage rating: 6v up to 32v​
  • Rated at 175A Continuous duty at 12V and 300A at intermittent use.​
Those figures are for the TMC switch, not all switches are the same, but i'd expect they would all cope easily with the inverter load above. I would still do away with the switch.

What size battery fuses are you using for the domestic bank ?
 

coopec

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Those figures are for the TMC switch, not all switches are the same, but i'd expect they would all cope easily with the inverter load above. I would still do away with the switch.

What size battery fuses are you using for the domestic bank ?


Thanks for your help.
I'll check the fuses tomorrow.

After this problem I think I'll install a 150A in-line circuit breaker. Good move?:unsure:

Screenshot 2022-01-28 at 17-16-50 150A AMP Circuit Breaker Car Marine Stereo Audio Inline Repl...png
 

PaulRainbow

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Thanks for your help.
I'll check the fuses tomorrow.

After this problem I think I'll install a 150A in-line circuit breaker. Good move?:unsure:

Your inverter will draw 150a continuous or up to 300a for a short time so you need to fuse for that, providing the cables are rated at 300a minimum, you've not said what size cables you have, it's important.

I wouldn't want to fit a cheap Ebay breaker for such a critical purpose.
 

coopec

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Your inverter will draw 150a continuous or up to 300a for a short time so you need to fuse for that, providing the cables are rated at 300a minimum, you've not said what size cables you have, it's important.

I wouldn't want to fit a cheap Ebay breaker for such a critical purpose.
Paul
I have a chart showing amperage for AWG/length and I never skimp so I am confident.
But I will check them again in the morning and work on 300A.
Thanks
 

VicS

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Paul
I have a chart showing amperage for AWG/length and I never skimp so I am confident.
But I will check them again in the morning and work on 300A.
Thanks
be warned that with very short cables ( you said 0.5m) basing their size on volts drop and length is likely to give you a cable size with a safe working load less than your actual load'

with cables this short select according to current alone.
 

PaulRainbow

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be warned that with very short cables ( you said 0.5m) basing their size on volts drop and length is likely to give you a cable size with a safe working load less than your actual load'

with cables this short select according to current alone.

That's a good point (y)

Voltage drop table shows that 16mm cable, 0.5m long, 300a current @12v is acceptable. Well, it may be acceptable for voltage drop, but it's only rated at 110a.
 

coopec

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be warned that with very short cables ( you said 0.5m) basing their size on volts drop and length is likely to give you a cable size with a safe working load less than your actual load'

with cables this short select according to current alone.

Vic/Paul

Thanks for your advice

I have a 6 inch cable from a battery terminal to a negative bus bar. I estimate the diameter of that cable is 8mm (of copper) which would equal AWG 1/0 . (On a short cable like that I go for an over-kill) I crimp the terminals: maybe I should use soldered copper terminals?

I looked at the 2ft cables that came with the inverter and immediately thought they were too light. But who am I to question the manufacturer?

Gauge-Chart.jpg


4ecd3082b6ee2fea1f36d8f8496bed0a.jpg
 
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William_H

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Clearly the 1,2,both switch is not up to the job. Any resistance in the contacts (dirt) will produce a volt drop and heating as indicated by the melted plastic.
With the high powered inverter I might advocate heavy wiring that is for you apparently very short. If you can keep these wires away from anything flamable it might be ok to not switch or fuse the wire. (assuming the inverter itself has a switch) You could end up with a system battery to inverter unfused like the wiring for a car battery to starter motor. The assumption that the wire can incandesce and get very hot in fault situation without setting fire to the boat. And or the wiring is so heavy that it can handle the max current the battery can provide. Plus the short wiring run is unlikely to short to any metal or the other wire.
The problem is that every external fuse and switch is a source of volt drop and fault with the high operating current.
As for the 1,2,both switch I do not like the idea. Battery systems should be designed for the purpose. ie engine start or deep cycle service batteries. The 1,2,both switch is usually set up with identical alternative batteries. I would advocate seperate engine battery system with high current isolation switch and a seperate service battery sytem also with high current isolation switch. You might fit a paralleling high current switch for emergency jump start. Or carry a jump lead. Negatives should be connected with high current cable. Fit a VSR voltage sensing relay for charging service battery from engine. Solar panels to service battery with perhaps a small solar panel for engine battery. (probably not needed) ol'will
 

PaulRainbow

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Vic/Paul

Thanks for your advice

I have a 6 inch cable from a battery terminal to a negative bus bar. I estimate the diameter of that cable is 8mm (of copper) which would equal AWG 1/0 . (On a short cable like that I go for an over-kill) I crimp the terminals: maybe I should use soldered copper terminals?

I looked at the 2ft cables that came with the inverter and immediately thought they were too light. But who am I to question the manufacturer?

The first chart is a great set of examples of what was mentioned in posts #15 and #16. As one example, top row, 250/300a needs 1/0 cable as a minimum, to carry the current. Yet the chart allows for as low as 4ga, which is only rated around 140a

You were right to question the manufacturer, those cheap end inverters come with stupid sized cables.

Nothing wring with crimping the terminal on, as long as you used a decent hydraulic crimper.
 

coopec

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Clearly the 1,2,both switch is not up to the job. Any resistance in the contacts (dirt) will produce a volt drop and heating as indicated by the melted plastic.
With the high powered inverter I might advocate heavy wiring that is for you apparently very short. If you can keep these wires away from anything flamable it might be ok to not switch or fuse the wire. (assuming the inverter itself has a switch) You could end up with a system battery to inverter unfused like the wiring for a car battery to starter motor. The assumption that the wire can incandesce and get very hot in fault situation without setting fire to the boat. And or the wiring is so heavy that it can handle the max current the battery can provide. Plus the short wiring run is unlikely to short to any metal or the other wire.
The problem is that every external fuse and switch is a source of volt drop and fault with the high operating current.
As for the 1,2,both switch I do not like the idea. Battery systems should be designed for the purpose. ie engine start or deep cycle service batteries. The 1,2,both switch is usually set up with identical alternative batteries. I would advocate seperate engine battery system with high current isolation switch and a seperate service battery sytem also with high current isolation switch. You might fit a paralleling high current switch for emergency jump start. Or carry a jump lead. Negatives should be connected with high current cable. Fit a VSR voltage sensing relay for charging service battery from engine. Solar panels to service battery with perhaps a small solar panel for engine battery. (probably not needed) ol'will

William

Thanks for your response.

I've just been up in the yacht (Phew! it is hot outside) and checked the brand of the Battery Selector Switch. It is AAA brand. The specifications are.

Rating at 12 volt
- 250 amp momentary
- 150 amp continuous

s-l1600.jpg


When I read the "Troubleshooting" part of the inverter manual it said if it cuts out wait 30(?) minutes and the start it again. I assumed from that it had a thermal cut-out. (There is no mention of external fuses)

I burned out one PWM Controller because I connected the controller to the panels before connecting to the battery. I have now installed switches on the solar panel cables so that I can disconnect my batteries without further drama. (I don't understand as my Son says he never disconnects the solar panels when he disconnects the battery on his work trailer)

I have a small 1/2/Both installed after the PWM Controller so I can direct the solar charge to the battery banks as required.

I made up some heavy duty jumper leads which will always be kept on the yacht.

Thanks
 
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