Ford Transit USA Forum banner

Forum Discussions about this Product

1 - 3 of 3 Posts
    1. · Registered
      Joined
      ·
      968 Posts
      Also, and this may be elementary, but how did you come up with the 208a load?
      For a 2000 Watt Inverter: To get input current, divide by battery voltage (12V) and divide by efficiency (80%). So I get 2000/(12V * 80%). 208Amps (lots of current!) Admitted that is worst case, but gives a ball park current load.

      Battery's are 220AH, normally that rate is for a 10 hour constant current discharge. So 22 Amps
      over 10 hours. Tojan flooded cells should be limited to about 4x that, or 88 Amps maximum for best life. Hence my concern about drawing than 100 Amps.

      looking at the Trojen spec sheet I see they listed 75 Amps for 115 Minutes. Working back from 75 Amps, 12 V battery, 80% efficiency gives a realistic inverter output of 720 Watts. Much more reasonable design load. Small 600W coffee maker, 75W TV, etc are possible with that load.

      So now we can plan around the wiring sized for 75 Amp Load. Putting in a 100 Amp Circuit Breaker will protect the wire from burning up, and should prevent nuisance trips (inrush maybe an issue).

      I still need time to figure out the Smart Pass & CTEK D250S, looks like Smart Pass can allow up to 80 Amps of current to flow into the house batteries. The CTEK 250S is for 20 Amps of current.

      Something to keep in mind about the battery charging of the house batteries, 80 Amps is maximum, but as the battery voltage comes up, the current drops.

      So if we look at that Van Battery to House Battery wire. Maximum is 80 Amps, short duty. We can allow a 10% voltage drop as we want the wire to limit current the the house battery. 6 AWG for the length given would be fine.

      Two breakers:
      Next to VAN battery: ANL circuit rated for 120 Amps.
      Next to House Battery: 100 Amp Circuit breaker:

      Source (things that provide power)

      1. Van Battery via Smart Pass 80 Amps (maximum, intermittent as this current drops as house batteries are charged up)
      2. Solar 20 Amps
      3. Ctek 2500 20 Amps
      Sink (things that consume power):

      1. Inverter 75Amp
      2. DC 12 Circuit 21 Amp
      3. DC 6 Circuit 25 Amps
      Things that can Source or Sink:

      1. House Battery By keeping the wire feeding it to 6 AWG, with 125C insulation, it will act like a resistor as it warms up limiting current flow. As you go though the design of the system you I'd keep house batteries to 75 Amp design, 100 Amp peak current.
      A 100 Amp Circuit breaker from the house batteries should work fine. I'd use something like this 100 Amp Breaker so if Uncle Fred plugs in his Kirby Vacuum Cleaner when on battery power it trips the breaker.



      Hopefully this makes a little more sense in dividing up loads source and sinks to get a better idea of the system approach to everything. On that 6 AWG wire, using rubber adel clamps (MS21919) to hold the wire, as allow it to remain in open air, is a good thing. That wire is your shunt to see the state of the house battery (being charged or discharged).



      Take a look at my comments and see if they make sense. Often my mind skips ahead of my fingers, and I make some crazy typo's. Once we are on the same page with source and sink currents, then time to start looking at wiring size and fuses to prevent fires!


      On my old race car, no fuses! If a critical fuse blew, we were DNF'd (did not finish). I would splice in fuse able links. 12 gauge circuit had a 16 gauge fuse able link. Learned the wisdom of separate circuits for right and left headlights (rally cars), redundant supply feeds (aircraft), so on. I've been at this electrical stuff I've forgotten more than I have known. So I do screw up and mix things up! Sigh. Good part is I have enough wisdom to realize there is much more to learn!
       
      • Like
      Reactions: Hein
    2. · Registered
      Joined
      ·
      637 Posts
      Discussion Starter · #110 ·
      For a 2000 Watt Inverter: To get input current, divide by battery voltage (12V) and divide by efficiency (80%). So I get 2000/(12V * 80%). 208Amps (lots of current!) Admitted that is worst case, but gives a ball park current load.

      Battery's are 220AH, normally that rate is for a 10 hour constant current discharge. So 22 Amps
      over 10 hours. Tojan flooded cells should be limited to about 4x that, or 88 Amps maximum for best life. Hence my concern about drawing than 100 Amps.

      looking at the Trojen spec sheet I see they listed 75 Amps for 115 Minutes. Working back from 75 Amps, 12 V battery, 80% efficiency gives a realistic inverter output of 720 Watts. Much more reasonable design load. Small 600W coffee maker, 75W TV, etc are possible with that load.

      So now we can plan around the wiring sized for 75 Amp Load. Putting in a 100 Amp Circuit Breaker will protect the wire from burning up, and should prevent nuisance trips (inrush maybe an issue).

      I still need time to figure out the Smart Pass & CTEK D250S, looks like Smart Pass can allow up to 80 Amps of current to flow into the house batteries. The CTEK 250S is for 20 Amps of current.

      Something to keep in mind about the battery charging of the house batteries, 80 Amps is maximum, but as the battery voltage comes up, the current drops.

      So if we look at that Van Battery to House Battery wire. Maximum is 80 Amps, short duty. We can allow a 10% voltage drop as we want the wire to limit current the the house battery. 6 AWG for the length given would be fine.

      Two breakers:
      Next to VAN battery: ANL circuit rated for 120 Amps.
      Next to House Battery: 100 Amp Circuit breaker:

      Source (things that provide power)

      1. Van Battery via Smart Pass 80 Amps (maximum, intermittent as this current drops as house batteries are charged up)
      2. Solar 20 Amps
      3. Ctek 2500 20 Amps
      Sink (things that consume power):

      1. Inverter 75Amp
      2. DC 12 Circuit 21 Amp
      3. DC 6 Circuit 25 Amps
      Things that can Source or Sink:

      1. House Battery By keeping the wire feeding it to 6 AWG, with 125C insulation, it will act like a resistor as it warms up limiting current flow. As you go though the design of the system you I'd keep house batteries to 75 Amp design, 100 Amp peak current.
      A 100 Amp Circuit breaker from the house batteries should work fine. I'd use something like this 100 Amp Breaker so if Uncle Fred plugs in his Kirby Vacuum Cleaner when on battery power it trips the breaker.



      Hopefully this makes a little more sense in dividing up loads source and sinks to get a better idea of the system approach to everything. On that 6 AWG wire, using rubber adel clamps (MS21919) to hold the wire, as allow it to remain in open air, is a good thing. That wire is your shunt to see the state of the house battery (being charged or discharged).



      Take a look at my comments and see if they make sense. Often my mind skips ahead of my fingers, and I make some crazy typo's. Once we are on the same page with source and sink currents, then time to start looking at wiring size and fuses to prevent fires!


      On my old race car, no fuses! If a critical fuse blew, we were DNF'd (did not finish). I would splice in fuse able links. 12 gauge circuit had a 16 gauge fuse able link. Learned the wisdom of separate circuits for right and left headlights (rally cars), redundant supply feeds (aircraft), so on. I've been at this electrical stuff I've forgotten more than I have known. So I do screw up and mix things up! Sigh. Good part is I have enough wisdom to realize there is much more to learn!
      Wowsa..thanks again. It may take me a minute to make complete sense of all this, but I'll keep reading into it as best I can. I'm sure I'll have some more questions.

      Sent from my SM-G950U using Tapatalk
       
    3. · Registered
      Joined
      ·
      637 Posts
      Discussion Starter · #111 · (Edited)
      So if we look at that Van Battery to House Battery wire. Maximum is 80 Amps, short duty. We can allow a 10% voltage drop as we want the wire to limit current the the house battery. 6 AWG for the length given would be fine.
      So are you saying I could use 6 AWG wire from van battery all the way to house battery (ie. from van to CTEK; instead of 4awg), from CTEK to positive buss bar; instead of 4 awg), and from positive buss bar to house battery; instead of 1/0 wire)? I think the inverter manual recommends a 2/0 or 1/0 for DC input wire.

      Two breakers:
      Next to VAN battery: ANL circuit rated for 120 Amps.
      Next to House Battery: 100 Amp Circuit breaker:
      Ok, so the 120a breaker next to van battery would be where i now have the 60a breaker? Or after CTEK (where I now have the 130a ANL fuse)?
      And the 100a breaker next to house battery would go between house battery and positive buss bar? Also, is the 250a MRBF fuse block that I have in my diagram on the house battery necessary?
       
1 - 3 of 3 Posts

Forum Reviews

Be the first to review this product

Write a Review

Do you have experience with this item? Help our community members and share your knowledge.

Sign in to add review

Top