sunshine_eggo
Happy Breffast!
Even less when you consider Peukert effect.
Inverter input breaker question
- Thread starter mervin101
- Start date
Even less when you consider Peukert effect.
thank you, running the space heater is for the day, like i mentioned it is a test system
Once you exceed a certain amperage (say 180 amps), your selection of DC breakers becomes very limited. For that reason, many implementations are using fuses instead of breakers.
I'm putting in a 2400 watt inverter that calls for a 400 amp fuse. I'm unlikely to ever draw that much, maybe not even half that amperage. I'm putting in a 300 amp MEGA fuse with the appropriate fuse holder. I'm buying extra 300 amps fuses as well as some 400 amp fuses, just in case.
Victron Energy 400 amp MEGA fuse
Victron Energy MEGA fuse holder
I'm putting in a 2400 watt inverter that calls for a 400 amp fuse. I'm unlikely to ever draw that much, maybe not even half that amperage. I'm putting in a 300 amp MEGA fuse with the appropriate fuse holder. I'm buying extra 300 amps fuses as well as some 400 amp fuses, just in case.
Victron Energy 400 amp MEGA fuse
Victron Energy MEGA fuse holder
acdoctor
Solar Enthusiast
You have gotten schooled on wire and breakers but no body has mentioned that you probably are pushing those batteries with the 100 amp draw. If you were needing 150 amps for motor start up that is one thing but a continuous draw is another. You should check your battery specs.
Thank you for the information. If I make this more permanent I will look at fuses. I bought a 250 amp breaker, so if that does not work, well it is a learning project
Is that a 250 amp DC breaker or a 250 amp AC breaker. A quality DC breaker of that amperage is fairly expensive.
As long as you don't push it, that should work. I wouldn't trust it above 200 amps, maybe not even that much.
I have a similar 150 amp circuit breaker on my 1000 watt inverter. It's a no-name breaker. I've pushed my little inverter hard a couple times, just to see what it would do. The inverter shutdown (went into overload mode) without the breaker tripping. That's probably the correct result as the breaker is rated for more amps than the inverter should ever be capable of drawing. The 150 amp breaker is what the manual recommended for the length of cable I used.
corn18
Village Idiot
- Joined
- Sep 9, 2021
- Messages
- 664
I would not use that breaker. Cheap crap that is not trustworthy. I used a Blue Sea 250A (model 7270) breaker before I went to a bigger system.
Those cheap “breakers” are known to be huge voltage drop/resistors well under their name plate rating.
As you slowly apply load on the inverter, watch its input voltage drop and that bkr will heat up something bad. The small contact patch alone should be the first concerning issue.
acdoctor
Solar Enthusiast
Schneider electric 117.00 on Amazon
Simple answer. 3500W inverter at 12 volts? The 12V cable must be sized to carry 300 amperes. For safety reasons, no matter the load. The distance from the battery to inverter, voltage drop will determine that cable size. I suspect at least 4/0 cable. If very short distance maybe 2/0 cable. 2/0 cable requires a 300A fuse. Using 4/0 cable allows a 400A fuse. Use a fuse. Circuit breakers do not like high DC amperes.
Sell the 12V 3500W inverter and get one appropriately sized for 12 volts.
Sell the 12V 3500W inverter and get one appropriately sized for 12 volts.
littleharbor2
Solar Addict
Kinda strange, The ad shows a chart specing #000 cable for 200 - 250 amp breaker yet the 250 amp breaker is shipped with a pair of #6 cable lugs. Hmmmm......
