Power invertor

[Rawze]

Thanks for the write-up LRT1549 ...

Just my own observation: I have this same exact inverter in my truck. I have no cut-off switch installed on mine. It seems to use little to no power when it is switched off. During home time, the truck can sit a month and it does not drain the batteries with the unit simply switched to the off position.

I DO HAVE 4/0 welding cables and adequate fuses, same as you described, but also I have a super-capacitor at the inverter as added electrical load stability and to prevent electrical noise.

here is a similar thread of the past that also talks about alternators and belts...
http://rawze.com/forums/showthread.php?t...6#pid54936

[LRT1549]

(08-07-2021 )Rawze Wrote:  Thanks for the write-up LRT1549 ...

Just my own observation: I have this same exact inverter in my truck. I have no cut-off switch installed on mine. It seems to use little to no power when it is switched off. During home time, the truck can sit a month and it does not drain the batteries with the unit simply switched to the off position.

Ya that's what I was saying. You can just shut it off at the switch on the inverter, but the cut off switch is just added safety.. However leave that inverter on, even with nothing using power, and it will drain the batteries...

[Explosia]

Is a 200 amp breaker common practice for all inverters? I used an 80 and it lasted 4 seconds.

[Rawze]

(08-10-2021 )Explosia Wrote:  Is a 200 amp breaker common practice for all inverters? I used an 80 and it lasted 4 seconds.

You need to size the fuse(or breaker) according to the WIRING size that was used to install the inverter. You need to also SIZE THE WIRING properly so that the correct amps to run the inverter can be supplied as well. It takes a LOT of amperage to run typical household appliances (10x plus all the losses) on a +12Volt Automotive system. Here are some real world ratings and values for that will yield a safe, highly reliable system, and compensate for those losses.


An 80-amp fuse in a typical inverter will only supply about 800-900 WATTS max (at 120Volts) before getting hot and/or popping. That is barely enough to power a typical household coffee maker.

3,500-4,000 WATTS inverters are known in the industry as a "Hotel Load" style inverters. Their continuous use ratings are usually a bit smaller at about 1500-1800WATTS . These style of 3,500 - 4,000 watt inverters would be the same power capacity as a typical single household outlet. They will be able to run a full power microwave or other single outlet appliances without overheating. Anything smaller, and it is going to get hot and/or easily overload if used heavily.

Tags:

truck wiring, battery size, inverter size, hotel load, wire size chart, alternator size

[Nilao]

The formula I use is Watts÷Output Volts×Input Volts=fuse size. So your typical 2500w inverter would be 2500/120×12=250 amps. Now that's if your using the correct wire size for the load. If your using say a wire that's .85 the proper gauge then you'd need a 300 amp fuse as the wire will need to carry more average to produce 2500w on the other end. So that 80A fuse will power a max output of

[Rawze]

(08-11-2021 )Nilao Wrote:  The formula I use is Watts÷Output Volts×Input Volts=fuse size. So your typical 2500w inverter would be 2500/120×12=250 amps. Now that's if your using the correct wire size for the load. If your using say a wire that's .85 the proper gauge then you'd need a 300 amp fuse as the wire will need to carry more average to produce 2500w on the other end. So that 80A fuse will power a max output of

Just an observation here ...

I don't know where that formula came from but it is severely flawed. That formula seems to coincidentally get someone in a ball-park range for +12Volts system (by the sheer coincidence that 120 volts is 10x the range of 12 volts), but it is some damaged mathematics. Imagine that someone tries to use that formula on a 24-volt or 48-Volt system in a boat or Solar array. It would be completely wrong, the math goes the wrong way.

The chart that I presented above is not based on any formulas but rather real world numbers and ratings instead. It includes compensations for those pesky advertised ratings of inverters vs. what can actually be achieved safely and effectively. This is so that someone does not have to get all confused when considering all of those things.

[snailexpress]

Just to keep everyone safe copied from Amazon reviews.
Check yours inverter.

1.0 out of 5 stars Shock and Fire Hazard
Reviewed in the United States on October 27, 2019
Size: 12V 3500W V1.0Verified Purchase
This inverter has NO business whatsoever being installed into any RV. In full truth, this inverter should NOT be sold in the United States of America at all. This inverter violates a basic assumed premise of every ...

[Rawze]

(08-11-2021 )snailexpress Wrote:  Just to keep everyone safe copied from Amazon reviews.
Check yours inverter.

1.0 out of 5 stars Shock and Fire Hazard
Reviewed in the United States on October 27, 2019
Size: 12V 3500W V1.0Verified Purchase
This inverter has NO business whatsoever being installed into any RV. In full truth, this inverter should NOT be sold in the United States of America at all. This inverter violates a basic assumed premise of every ...

take amazon reviews with a grain of salt.