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nh3 type fuses rate...
 
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nh3 type fuses rated for DC

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(@dickson)
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The German electrician said I could parallel 3 of the Siemens 160 Amp NH fuses but would need cable to support 480 Amps then..

You can use two awg 4/0 cables to connect the 3 Siemens 160 Amp NH fuses    IT is too expensive to use one 480 Amps cable .  


   
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(@dickson)
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my 5000-watt inverter will have 2 4/0 cables one to each terminal >>>> 2 negatives and two positive 4/0 cables, ((two positives 4/0 cables, two negative 4/0 cables)

A 5000-watt inverter if it is a powerjack  will not output 5000 watts .  One  positives 4/0 cable and  one  negative 4/0 cable will work .   The GS6kw inverter only has 2 terminals and Sean use one  positives 4/0 cables and  one  negative 4/0 cables .    Even the GS12kw inverter has only 2 terminals .  The GS12kw should have two positive terminals  and 2 negative terminals  to carry 12000 watts .  I use two 4/0 positive cables  and two 4/0 negative cables on my powerjack 30kw .      


   
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pilgrimvalley
(@pilgrimvalley)
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How do I know what size fuse to use?
 
First, you will need to determine the maximum fuse rating in amperages by applying this formula for calculation: P (Watts) ÷ V (Voltage) = I (Amps). Next, you will need to calculate the minimum fuse rating or amperage by multiplying that total (the maximum amperage rating) by 125%. Apr 12, 2022

   
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pilgrimvalley
(@pilgrimvalley)
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@dickson not a powerjack

 


   
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pilgrimvalley
(@pilgrimvalley)
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Posted by: @dickson

The GS12kw should have two positive terminals  and 2 negative terminals  to carry 12000 watts .

 

yes I think from the electrical folks I have talked to >>>> that two terminals for positive and two terminals for negative is better to distribute the amperage...

 


   
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pilgrimvalley
(@pilgrimvalley)
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the 5000-watt inverter has 2 positive and 2 negative terminals....it is 24-volts but has shown to run the full 5000-watts but it is not a Powerjack.

I have a 15000 watt Powerjack 24-volt inverter that has 2 positive and 2 negative terminals to connect to the battery also ..


   
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(@dickson)
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Yes you need  2 positive and 2 negative terminals.   Powerjack web page say for any inverter  24vdc and over 4500 watts must have 2 positive and 2 negative cables .  Wes the tech guy on Youtube say the awg 4/0 cable is cool  at room temperature  otherwise the cable is too  small .  I am still assembling my battery .  


   
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pilgrimvalley
(@pilgrimvalley)
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the electrician from Germany said to use 24 volt or 48 volt in the fuse sizing calculations

so 6000 watts divided by 24 volts equals 250 Amps

then upsize the fuse by the 1.25 factor equals 250 x 1.25 = 312.5 Amps for the 24 volt 6000 watt inverter

5000 divided by 24 x 1.25 = 260 Amps >>> (((((but the inverter actually says 6000 watts... with a 12000-watt peak (although it will never do that)))))

the closest I have is 355Amp NH fuse,  >>>>..so I will have to find a more appropriate sized fuse for 6000-watt inverter loads...

I also note that LiFePO4 batteries are tested for energy at the factory and not Ah.... according to "Average Joe's" YouTube video I was watching...

energy or power is measured in Watts Wh (hope I got that part stated right)????

I think Andy was also showing that same style of measurement on his "off-grid garage" YouTube videos with the LiFePO4 battery testing 

seems like learning the correct jargon and expressing things correctly is always a learning process when it is not your 1st or main profession....

This post was modified 10 months ago by pilgrimvalley

   
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pilgrimvalley
(@pilgrimvalley)
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You don't calculate with the actual voltages (25.6V) but instead with 24V or 48V to have some security
that is what the electrician stated...
 
 

   
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(@dickson)
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You post  the closest I have is 355Amp NH fuse,  >>>>..so I will have to find a more appropriate sized fuse for 6000-watt inverter loads.

The fuse is to protect the  cable .  One  AWG 4/0  will carry 230 amps .  A 6000 watt 24 vdc inverter will produce 313 amps need two AWG 4/0 cables  that can carry  460 amps .  A 355Amp NH fuse  can be use  to protect the  2 cables .  A  5000 watts 24vdc produce 260 amps and  if you use 2  AWG 4/0 cables then a 355Amp NH fuse will also protect   the 2 cables .  


   
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pilgrimvalley
(@pilgrimvalley)
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@dickson yes>>>> the 24-volt 6000-watt inverter has 2 positive and 2 negative posts for connection to the battery....

so headed in the right direction.... thanks for the replies!

 

 


   
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pilgrimvalley
(@pilgrimvalley)
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when I asked the reason for the 2 posts for negative and 2 posts for positive on my 15k 3pc 24volt inverter .... seems like sxx(don't mention his name) 🤔🤔said I did not need to hook to both as they are connected internally to the same place....

but now I think it would be a lot better to have 2 4/0 cables to positive and 2 4/0 cables to negative to carry the heavier loads and have less heat generated...(each 4/0 copper connected to separate terminals on the inverter)

This post was modified 10 months ago by pilgrimvalley

   
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(@dickson)
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Powerjack web page say the 2 posts for negative and 2 posts for positive on your  15k 3pc 24volt inverter is needed  to have 2 4/0 cables to positive and 2 4/0 cables to negative to carry the heavier loads and have less heat generated...(each 4/0 copper connected to separate terminals on the inverter) . 

Screenshot (2818952)

 


   
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pilgrimvalley
(@pilgrimvalley)
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I have to wonder if some people purposely give the wrong advice or they lack a complete understanding of the requirements for safely operating high loads on a DC inverter...

names purposely withheld and it is not Dickson either.... 

I bought a 3-pole disconnect for the NH-type fuses that should arrive soon....

the disconnect is rated for DC....

hopefully, never blow the Dc fuses but hey are there for safety reasons.... as catastrophe conditions....


   
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