fuse between inverter and load?

[dcac]

hello
i have a question on off grid system
if i have a system like this :
panels-----charge controler-----battery--------inverter---------load

normaly ,i do put a fuse between battery and inverter ,but do i need to put ac breaker or fuse between inverter and load
and if a suppose that a short circuit happen on load ,what fuse will shut down the first between battery and inverter or the one between inverter and load

[thastinger]

You need to list some specs on what you're working with on the equipment side.

You need DC breakers/fuses between the panels and CC, probably in some sort of combiner box
Also between CC and battery (some CC have ground fault and arc fault built in)
Also between inverter and load (normal household AC panels and breakers are fine here)

[dcac]

You need to list some specs on what you're working with on the equipment side.

You need DC breakers/fuses between the panels and CC, probably in some sort of combiner box
Also between CC and battery (some CC have ground fault and arc fault built in)
Also between inverter and load (normal household AC panels and breakers are fine here)

hello
yes ,but if a suppose that a short circuit happen on load ,what fuse will shut down the first,the one between battery and inverter or the one between inverter and load

[Sunking]

What kind of an Inverter?

Most battery inverters require no over current protection of any kind on the output because they cannot deliver enough current to operate an over current protection devise (OCPD). Now if you are talking about an inverter made to be used in a premises wiring system is a different story. But most of your battery inverters are not designed or have enough power to require OCPD on the outputs. In other words cannot be used in premises wiring systems. Instead they use GFCI circuits or shut down when over loaded. Those are point of use aka mobile inverters. No ground required.

[SunEagle]

hello
yes ,but if a suppose that a short circuit happen on load ,what fuse will shut down the first,the one between battery and inverter or the one between inverter and load

It could be either fuse or both at the same time. It will depends on the type, size and melt point of the fuse as well as the amount of short circuit current being generated.

A lot of industrial companies perform what is called a "coordination study" which will help them set up their over-current protection (fuse & CB) to isolate the problem as close to the short circuit as possible. There have been incidents where a small low voltage load shorted out causing a much bigger breaker up stream to open.

We need to have more data on your equipment, fuses and load current to give you a precise answer.

[dcac]

What kind of an Inverter?

Most battery inverters require no over current protection of any kind on the output because they cannot deliver enough current to operate an over current protection devise (OCPD). Now if you are talking about an inverter made to be used in a premises wiring system is a different story. But most of your battery inverters are not designed or have enough power to require OCPD on the outputs. In other words cannot be used in premises wiring systems. Instead they use GFCI circuits or shut down when over loaded. Those are point of use aka mobile inverters. No ground required.

thank you
suppose the inverter is used to power for exemple a house, (room1 electric sockets ,tv,computer ..etc) room2(electric sockets ,fridge)...etc that means that i have to use many ac breakers to protect each room ,
the problem is that the fuse between battery and inverter is a dc fuse ,and the one after the inverter is an ac breaker?
also did the inverter support the short circuit current before the ac fuse shot down?

[dcac]

It could be either fuse or both at the same time. It will depends on the type, size and melt point of the fuse as well as the amount of short circuit current being generated.

A lot of industrial companies perform what is called a "coordination study" which will help them set up their over-current protection (fuse & CB) to isolate the problem as close to the short circuit as possible. There have been incidents where a small low voltage load shorted out causing a much bigger breaker up stream to open.

We need to have more data on your equipment, fuses and load current to give you a precise answer.

thank you
suppose the inverter is used to power for exemple a house, (room1 electric sockets ,tv,computer ..etc) room2(electric sockets ,fridge)...etc that means that i have to use many ac breakers to protect each room ,
the problem is that the fuse between battery and inverter is a dc fuse ,and the one after the inverter is an ac breaker?
also did the inverter support the short circuit current before the ac fuse shot down?

[SunEagle]

thank you
suppose the inverter is used to power for exemple a house, (room1 electric sockets ,tv,computer ..etc) room2(electric sockets ,fridge)...etc that means that i have to use many ac breakers to protect each room ,
the problem is that the fuse between battery and inverter is a dc fuse ,and the one after the inverter is an ac breaker?
also did the inverter support the short circuit current before the ac fuse shot down?

Again it comes down to needing more information.
What is your battery voltage?
What type and size is your DC fuse between the battery and inverter?
What is the wattage of your inverter and is there any "over current" protection internal?
What type & size AC circuit breakers are you using?

Based on your example you are looking at a very big inverter to run those AC loads. Which in turn requires you to have a big battery system to provide the power to the inverter.

Depending on the size of your inverter you could have more than one circuit. If you have more than one "circuit" (one for each room) then you could put a CB for each circuit provided it protected the wire for each circuit.

[dcac]

Again it comes down to needing more information.
What is your battery voltage?
What type and size is your DC fuse between the battery and inverter?
What is the wattage of your inverter and is there any "over current" protection internal?
What type & size AC circuit breakers are you using?

Based on your example you are looking at a very big inverter to run those AC loads. Which in turn requires you to have a big battery system to provide the power to the inverter.

Depending on the size of your inverter you could have more than one circuit. If you have more than one "circuit" (one for each room) then you could put a CB for each circuit provided it protected the wire for each circuit.

what i need to know is if i have a big battery and a big inverter ,what fuse/breaker will shot down the first if a short circuit happen after the inverter?the dc or the ac fuse/breaker ,because if the ac breaker shot down the first that means that the inverter was passed by the short circcuit current and can be damaged,this mean what will be the utility of the ac breaker

[inetdog]

what i need to know is if i have a big battery and a big inverter ,what fuse/breaker will shot down the first if a short circuit happen after the inverter?the dc or the ac fuse/breaker ,because if the ac breaker shot down the first that means that the inverter was passed by the short circcuit current and can be damaged,this mean what will be the utility of the ac breaker

There is no simple way to predict which fuse (AC side or DC side) would open first, especially if they are both sized to a full load on the inverter. However most inverters also have built-in circuitry to protect their output against overload.
This assumes that the overload or the short circuit (could be either, with different results) is outside the inverter itself, on the load side.

The DC fuse is necessary to protect the inverter and the wiring against a short circuit in the inverter itself. Since a fuse can handle a small overload for quite awhile, I would expect an undamaged inverter to shut down before either the AC or DC fuses blew.

[dcac]

i need to know, if the inverter can shot down before the ac fuse/breaker after the inverter when a short circuit happen on the load side ,what will be the job of the fuse/breaker?

[inetdog]

i need to know, if the inverter can shot down before the ac fuse/breaker after the inverter when a short circuit happen on the load side ,what will be the job of the fuse/breaker?

It will be there to protect the wiring against a fault in the inverter itself (maybe combined with a problem on the load side) and it will be useful as a disconnect when working on the wiring. Just turning the inverter off may not be completely safe.

[dcac]

thank you all for your help