Blowing 400amp fuse

[gslabbert5119]

Thoughts on this ...
Do I have something shorting or do I have the incorrect fuse type, or is there another reason that you guys can come up with.


My wife uses the microwave 1500watts and the kettle 1500watts at the same time and it immediately blows the 400amp ANL fuse (happened twice in 2 days) that protects the Inverter charger. The inverter charger is a 3000w that should be able to handle a surge of up to 9000w
My little electrical knowledge tells me that 3000w at 120v = 25amps

I do not find a short, and both appliances work just fine independently and neither 15 breaker that supplies kettle curciot or the 20 amp breaker that supplies the microwave trips

Inverter specs below ...

Thoughts ideas and suggestions are most welcome.


Inverter Output Specifications:

• Listed to UL 458 Standards
• Continuous Output Power: 3000 Watts
• Surge Rating: 9000 Watts (20 Seconds)
• Output Waveform: Pure Sine/Same as input (Bypass Mode)
• Output Voltage: 100-110-120Vac
• Nominal Efficiency: >92% (Peak)
• Line Mode Efficiency: >95%
• Output Frequency: 50Hz +/- 0.3Hz / 60Hz +/- 0.3Hz
• Bypass Terminal Breaker - 40 amps
  [*]Typical Transfer Time: 10ms (Max)
  [*]THD: < 10% DC

Input Specifications:

• Nominal Input Voltage: 12.0Vdc
• Minimum Start Voltage: 10.0Vdc
• Low Battery Alarm: 10.5Vdc-11.0Vdc
• Low battery Trip: 10.0Vdc-10.5Vdc
• High Voltage Alarm: 16.0Vdc
• Low Battery Voltage Restart: 13.0Vdc
• Idle Consumption: 55 Watts
• Charger breaker - 30 amps
  [*]Power Saver Mode Idle Consumption:21.7 Watts

Charger Specifications:

• Output voltage: Depends on battery Type
• Charger Rate: 100A

 

[Garypowell]

My little bit of electrical knowledge tells me that electrical loads will draw 1.5 times their rating for a short time while they start....now this might be motors only.

But maybe your 400 amp is a quick blow type fuse and it goes in that instant of start up.

 

[avvidclif]

Are you sure you didn't mean 40A?

 

[gslabbert5119]

My little bit of electrical knowledge tells me that electrical loads will draw 1.5 times their rating for a short time while they start....now this might be motors only.

But maybe your 400 amp is a quick blow type fuse and it goes in that instant of start up.

See this is EXACTLY why I posted the question, I always thought that a fuse was a fuse was a fuse.
Now I have to research quick blow versus some other type of fuse.

I am willing to bet tha e fuse is a quick blow fuse, , so what type of fuse should I have installed ?

Thanks
Gavin

 

[SNOKING]

If these are the fuses you are using, maybe you need a higher quality fuse.

https://www.ebay.com/i/112603753726?chn=ps

Chris

 

[gslabbert5119]

See this is EXACTLY why I posted the question, I always thought that a fuse was a fuse was a fuse.
Now I have to research quick blow versus some other type of fuse.

I am willing to bet that the fuse is a quick blow fuse, so what type of fuse should I have installed ?

Thanks
Gavin

Exactly those type of fuses, but from Amazon. As I have said, I always believed that a fuse is a fuse is a fuse, and clearly I am wrong...

 

[avvidclif]

Get a Slow Blow. The fast acting reacts to any over current situation.

 

[gslabbert5119]

Thanks, I just ordered one and a spare fuse

 

[CarterKraft]

AMSolar specs a Class T fuse for this.

https://amsolar.com/rv-inverter-accessories/fuse-clst

 

[avvidclif]

Thinking on it. 25A @ 120v = ~250A @ 12. Now factor in surge 120 @ 75 = 750 @ 12. Yep blow a 400A fuse.

 

[CarterKraft]

According to this littlefuse data sheet on page 6, a class T 400A fuse should be more than plenty.

I guess I need to look for a ANL fuse datasheet?

 

[orion7144]

I have the same AIMS inverter/charger and I originally put 300A fuses in and they were blowing every time my EMS shut down and the inverter kicked in. I too was using the cheapo fuses and have since installed a quality 400A fuse. Now if you at the specs of the AIMS, the reason it happens if it is not a quality slow blow fuse is the fact that it has a 9000W 20 second surge capacity.

- - - Updated - - -

Forgot to mention that there is a significant weight difference with the better fuse. Definitely better quality.

 

[CarterKraft]

Not to be a stick in the mud but there seems to be allot of people on this site purchasing sub-par, import, no-name breakers and fuses.

If you think about the purpose of the fuse, the top thing on my list is fire prevention so buying a un-rated copy cat fuse/breaker sounds crazy to me. A similar comparison might be a smoke detector from a Chinese importer, I think its better to spend the extra cash on this stuff.

Signed the cheapest guy...

 

[CDN]

If you calculate the load at 92% efficiency you are running into the surge area of capacity when using the loads as described. With loss of connections on the DC side of things I could very well see the Invertor popping the fuse. A Slow Blow is a good suggestion, order a spare too. Figuring 9000 watts at 13 volts the current is 692 amps.

How did the fuse fail was it? Black or just melted?

 

[gslabbert5119]

A Slow Blow is a good suggestion, order a spare too. Figuring 9000 watts at 13 volts the current is 692 amps.

How did the fuse fail was it? Black or just melted?

The fuse was Black, this is the 2nd time and both fuses were black.

I ordered a Go Power Slow blow fuse specifically for inverters, and a spare in 400amp, hopefully that is enough not to blow but low enough to protect the circuits.

Thanks
Gavin

 

[Bones]

I think your fuse might be on the light side of things. You probably need somewhere around 900 amp or 1000 amp fuse.

 

[SNOKING]

I think your fuse might be on the light side of things. You probably need somewhere around 900 amp or 1000 amp fuse.

Multiple sites list 400 amp fuse for a 3000W inverter. Chris

 

[Bones]

My bad I saw the 9000 watts missed the 3000 watts but at 9000 watts for 20 seconds is a lot of amps for a 400 amp fuse.

 

[gslabbert5119]

My 400 amp T-Type slow blow fuse is in and it works great.

Thanks all

 

[Gaffer]

If you over fuse anything you are at risk for fire.