Input on my Trailer Battery Box Plan

#1
Hi

I'm finalizing my plans on the battery box and would like to get experts advise about my plans.

Power consumption as estimated below 30amps at any given time (Shurflo pump, a few LED light strips, charging phones). Output from the solar panel is well below 30 amp. Output from the CTEK 250SA is 20 Amp max. Everything other than the Solar panel (100W) is going to in a plastic box on the trailer. I attached my drawing for the plan below.

My readings online suggest that I don't need to fuse the cables if they are short in distance (shorter than 18"). The solar panel cables will probably be 4 feet from the box (with possible extensions to follow the sun). Since everything else is within a box, I did not include fusing the cables in my plans. I have inline 30 amp 10 AWG fuses on hand though if needed. Everything before the fuse block is 10 AWG solar cable. After that, 16 AWG to individually fused circuits.

1) Am I on the right track not fusing within the battery box beside the fuse block?

2) Should I fuse the cables from the panel to the CTEK 250SA? If yes, right after the solar cable coming from the panel?

3) If I were to add a 10 AWG cable from the 7-pin power line to feed the CTEK while driving, should I fuse it and where?

4) Any thing else I'm missing? Screen Shot 2018-06-13 at 8.57.15 AM.png

Thanks in advance for your advice and time.
 
#2
Looks ok to me.
Fusing is engineering choice based on several factors.
Solar to CTek is not really needed as the 100W solar cant produce enough power to harm 10awg conductors. Battery to mainswitch and fuseblock is often safely omitted if as your description, short length & within same enclosure, not likely to suffer damage, etc. Its still a good idea between CTek and battery. Even if fitting short distance parameter. Unlike the fuseblock which is a simple and if good quality, robust mechanical conductor assembly, a failure of the mystery electronic dohickeys within the CTek could cause excessive current on CTek to battery connection or CTek itself to burn.
Thanks! Appreciate the input!

For the following, are you talking about starter battery to CTEK through the 7-pin?
Its still a good idea between CTek and battery. Even if fitting short distance parameter. Unlike the fuseblock which is a simple and if good quality, robust mechanical conductor assembly, a failure of the mystery electronic dohickeys within the CTek could cause excessive current on CTek to battery connection or CTek itself to burn.
If so, I'd assume a fuse right after the trailer wiring box on the 10 AWG wire going to the alternator side of the CTEK. What size fuse would you recommend? 40 amp?

Thanks again!
 
#3
No, CTek to deepcycle. 7 pin circuit should be fused within the car.
If a fuse is between CTek & deepcycle, a possible high fault current path from deepcycle outbound on the 7pin is protected.
Nice! A Second reading cleared that message. Since the output of the CTEK is 20Amp, I'll put a 30 Amp fuse between the CTEK and Battery.

Thanks again
 
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