I need help with an electric issue.

[Reefering1]

I believe you, I just don't understand why this suddenly started happening.

Bestek 500 watt

Me either, the Amazon links stopped working- idk why, other sites still work.

So it appears there are (2)40a fuses on the back of the inverter, can you verify this? (Pretty sure 40a is orange fuses) If so that's all the protection it needs. Remove the 15a fuse on the battery lead entirely. It states to expect only 150w available on the 15a fuse on cigarette lighter adapter.

Make sure your 12v power wires are at least as large diameter as the wires coming out of inverter. looks like 12gauge, i would use 10guage.

 

[Dom]

Me either, the Amazon links stopped working- idk why, other sites still work.

So it appears there are (2)40a fuses on the back of the inverter, can you verify this? (Pretty sure 40a is orange fuses) If so that's all the protection it needs. Remove the 15a fuse on the battery lead entirely. It states to expect only 150w available on the 15a fuse on cigarette lighter adapter.

Make sure your 12v power wires are at least as large diameter as the wires coming out of inverter. looks like 12gauge, i would use 10guage.

So the breaker off of the battery is not necessary?

My wiring is 12 gauge throughout.

 

[BeanAnimal]

The deep cycle battery is likely capable of 100A — it looks like the 15A fuse is to protect the cars lighter circuit, which is most likely 15A bus or blade slo-blo fuse.

If you are building things like this, you really should have a decent meter and current clamp. While 12V does not sound dangerous, 100A or a shorted marine battery can generate tremendous amounts of heat — as in welding a wrench to a car frame if shorted, etc.

On that note. Without exception, positive terminal is always hooked up before negative and negative is always unhooked before positive. You never… ever put a wrench on a positive battery connection if the negative is connected…. Ever. You never wear a ring when working on batteries — wrench, ring, accidental short, 100 cold cranking amps through heating element on finger (the ring) —severe finger burn or worse (think the worst).

 

[Reefering1]

So the breaker off of the battery is not necessary?

My wiring is 12 gauge throughout.

Did you look at it? Does it have the 2 fuses on the inverter itself? If so, a additional fuse, at the battery, only protects the wire between. Doesn't really matter if they are 2 feet away from each other, would be nice to have if you have 30' of wire between them. And in that case, a 80@ fuse would be appropriate for that 500w inverter.

 

[jsmkmavity]

Breakers used at or near capacity will overheat internally weakening the metal inside that makes it trip. It will trip, get reset, then trip again/get reset again, and will continue to trip easier and quicker with even less load. The same thing happens on gfi outlets. They work fine for years then one day start to trip every time you use your hair dryer.

 

[jsmkmavity]

Do you have a test meter with ohm setting to check resistance?

 

[Dom]

Did you look at it? Does it have the 2 fuses on the inverter itself? If so, a additional fuse, at the battery, only protects the wire between. Doesn't really matter if they are 2 feet away from each other, would be nice to have if you have 30' of wire between them. And in that case, a 80@ fuse would be appropriate for that 500w inverter.

Yes, I looked. It does have 2 fuses on the inverter. Looking at the drawing (I'm reluctant to call it a schematic) I see what you mean when you say that additional breaker only protects the wire.

 

[Dom]

The deep cycle battery is likely capable of 100A — it looks like the 15A fuse is to protect the cars lighter circuit, which is most likely 15A bus or blade slo-blo fuse.

If you are building things like this, you really should have a decent meter and current clamp. While 12V does not sound dangerous, 100A or a shorted marine battery can generate tremendous amounts of heat — as in welding a wrench to a car frame if shorted, etc.

On that note. Without exception, positive terminal is always hooked up before negative and negative is always unhooked before positive. You never… ever put a wrench on a positive battery connection if the negative is connected…. Ever. You never wear a ring when working on batteries — wrench, ring, accidental short, 100 cold cranking amps through heating element on finger (the ring) —severe finger burn or worse (think the worst).

These are good safety tips, and I thank you for sharing them. I never worried about getting injured working with a 12 volt battery. But I see now that I should be more cautious.

 

[Dom]

Do you have a test meter with ohm setting to check resistance?

Which points would you like me to check?

 

[jsmkmavity]

Sometimes the contacts inside the ats can get corroded. Test from the left prong (with it facing you) on the cord end to the right plug slot on the outlet of the ats. You should have 0 or near 0 resistance. Another thing to check is without moving the heater(s) unplug and check for continuity from the metal prongs on the cord end to ground in an outlet or something metal around the tank, and also from cord prongs to the water in the sump. There should be no continuity, (infinite resistance).

 

[Dom]

Sometimes the contacts inside the ats can get corroded. Test from the left prong (with it facing you) on the cord end to the right plug slot on the outlet of the ats. You should have 0 or near 0 resistance. Another thing to check is without moving the heater(s) unplug and check for continuity from the metal prongs on the cord end to ground in an outlet or something metal around the tank, and also from cord prongs to the water in the sump. There should be no continuity, (infinite resistance).

Didn't forget; I will post findings tomorrow.

 

[BeanAnimal]

I am not following the troubleshooting path here. Sure you can check continuity on stuff and make sure you don't have dirty contacts, but if the 15A breaker between the batteries and inverter is tripping, then it would be somewhat expected. It is being overloaded by the inverter and doing exactly what it is designed to do.

The "delay" is due to the trip curve for that breaker. At 15A it will not trip... at some tiny percentage over 15A it make takes hours to trip.... at higher current, it will trip faster. It may not "instantly" trip unless it is at some number like 50A. You won't know unless you look up the curve for the breaker.

an example:

 

[robanister]

Not sure if it was said but it sound like you have surge!.... in residential if you have 10 amps running you put 20 amp breaker. Another example 240 water heater runs on 20 amps but requires 30 amp breaker. Heat pump 30 amps has 40 amp breaker.

 

[workhz]

Not sure if it was said but it sound like you have surge!.... in residential if you have 10 amps running you put 20 amp breaker. Another example 240 water heater runs on 20 amps but requires 30 amp breaker. Heat pump 30 amps has 40 amp breaker.

Don’t think this is quite right.

Also thermal breakers

 

[Dom]

I am not following the troubleshooting path here. Sure you can check continuity on stuff and make sure you don't have dirty contacts, but if the 15A breaker between the batteries and inverter is tripping, then it would be somewhat expected. It is being overloaded by the inverter and doing exactly what it is designed to do.

The "delay" is due to the trip curve for that breaker. At 15A it will not trip... at some tiny percentage over 15A it make takes hours to trip.... at higher current, it will trip faster. It may not "instantly" trip unless it is at some number like 50A. You won't know unless you look up the curve for the breaker.

I've reached out for help here as my experience level on this topic is limited. And in the interest of transparency, I've made some mistakes. They are:

1. When I purchased the parts to build this backup system, it was supporting a 40 gallon tank with a return pump, skimmer and 1 generic power head. As time has gone by, I've moved this backup system to larger tanks, but never upgraded the capacity of the backup system itself. Mistake 1.
2. To be clear, what I reported as a 15 amp breaker, was only 10 amp. And while the breaker was adequate to support the demands of smaller systems when it was assembled, the demands of the current system are much greater. I added a pair of Nero 5s to the system, which added an extra 60 watts to the demand. It wasn't until @ThisIsTheWay put the math in front of me that I saw this. Mistake 2.

It appears that there are multiple issues with this backup that I only discovered when the system called on battery backup and failed. For this, I blame myself as I tend to "set it and forget it" when I should do monthly tests to check for proper operation.

Steps taken so far:

• New GFI outlet.
• Upgraded existing breaker to 20 amp.
• New Auto transfer switch - current switch is changing over to battery when power goes out, but does not switch back to utility when power comes back on. I expect it will arrive today.

So, with the exception of battery and inverter, I've replaced all the components.

 

[SteveMM62Reef]

Motors have a high inrush current draw. Usually it’s very close to Lock Rotor Amps. Also the Battery Voltage will drop, when a motor hits start current, which furthers the high current “Amp.Draw.” small pump motors usually don’t display that value. Can you redo your set up, and get rid of the inverter? On my 12 Vdc Wet Cell Battery Backup I use multiple independent 12 Vdc Pumps. Loss of power, the pumps feed directly off of the battery. I’m not moving as much water, but I found out I don’t need to. My Maximum outage was 34 hours, with no problems.

 

[Dom]

Can you redo your set up, and get rid of the inverter?

I suppose I could, but that would cost a lot of money.

All equipment in the tank would have to be replaced; return pump, skimmer pump and power heads would all have to be replaced. And I can't justify replacing working equipment.

 

[BeanAnimal]

If you are building and maintaining things like this, a decent tru RMS meter with a current clamp would be a useful purchase. Fluke 301D is about $120 and a decent “pro” meter for home use.

 

[Dom]

If you are building and maintaining things like this, a decent tru RMS meter with a current clamp would be a useful purchase. Fluke 301D is about $120 and a decent “pro” meter for home use.

I have both.

 

[jsmkmavity]

I am trying to help make sure there arent any other problems in addition to the known one of too small of a breaker. If the contacts have resistance it will draw more amps than normal andnif the heater is failing the other test will reveal that.