A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: SolarVet on February 14, 2013, 12:27:22 PM

Title: FUSING !! AND HEAT !
Post by: SolarVet on February 14, 2013, 12:27:22 PM
Does it matter on which side the fusing should be placed with the MIdnight Classic to the batteries,,  Does it matter Positive or Negative Side.
I am currently using a 100 amp ANL fuse on the Negative side. And I notice alot of heat being generated at the Fuse block. I am using 4 ga wire.
Is this normal or should I switch to the Positive side.
Title: Re: FUSING !! AND HEAT !
Post by: Resthome on February 14, 2013, 12:54:19 PM
Quote from: SolarVet on February 14, 2013, 12:27:22 PM
Does it matter on which side the fusing should be placed with the MIdnight Classic to the batteries,,  Does it matter Positive or Negative Side.
I am currently using a 100 amp ANL fuse on the Negative side. And I notice alot of heat being generated at the Fuse block. I am using 4 ga wire.
Is this normal or should I switch to the Positive side.
Normally you would have a Fuse at the battery positive and a breaker near the Classic on the positive battery feed. How many amps are you feeding into the batteries and how long is the cable run round trip from the Classic to the batteries?

Note you need to know the lenght of both positive and negative batteries cables to size the wire.
Title: Re: FUSING !! AND HEAT !
Post by: SolarVet on February 14, 2013, 02:29:35 PM
Both Cables feeding the battery Bank is 10 feet Long...Amps usually around 50-80 depending on conditions.
Title: Re: FUSING !! AND HEAT !
Post by: niel on February 14, 2013, 07:34:57 PM
point 1> you should not be noticing heat off of the fuse block as that is indicative of bad connections and could be a source of voltage drop as well as other problems that could include a fire as well. look it over well and be sure all wire connections are good.

point 2> #4 wire will pose a voltage drop at 12v operation around 4.2% with 80a through it. at 24v it will be half that or 2.1% and at 48v it'll be half again for 1.05%. your total losses from pvs to batteries should be as low as possible without going broke and i believe midnite recommends that to be under 2%. 3% may be tolerable for when it is a difficult situation like high costs due to very long wire runs.
Title: Re: FUSING !! AND HEAT !
Post by: SolarVet on February 15, 2013, 04:28:44 PM
Thanks on the feedback on this, I think my solution will be is to Double up instead of 1 pair I will use 2 pair. I will see how this pans out.