HEINEMANN 250 AMP DC CIRCUIT BREAKER

Re: HEINEMANN 250 AMP DC CIRCUIT BREAKER

The HEINEMANN breakers are a top of the line manufacture of DC breakers. They are used a lot in telecommunication power systems. You can find great deals on e-bay. I have a few of the 250 amp breakers myself as backup for the ones that came with my Trace inverter power panel.
arcandspark

Re: HEINEMANN 250 AMP DC CIRCUIT BREAKER

SLOKUTA,  I am a believer in following the NEC code to the letter. There is a section in the NEC code book that tells about proper clearances inside an enclouser. The  metal box you are going to put the breaker in must have the correct clearance between the sides of the metal box and the current carrying terminals. I do not remember the section number off the top of my head but for some reason 2 to 3 inches of clearance keeps popping up in my memory banks. I built a DC fuse box using a Hoffman 24 x 24 x 8 box and had two 400 amp Trace fuses inside with all copper buss bar connections. Under the box I used to Anderson Quick disconnects with handle latches. I built it according to NEC code but I had to use fiber glass FR4 circuit board material on ths inside of the box with a fiber glass FR-4 covers to separate the current carrying terminals from the metal box because my box was a couple insches to small inside. Trace makes a 250 amp DC disconnect you can find a picture of it on the web to see about how big your metal box is going to have to be. Try to find the NEC section that talks about clearances. I will try to find it myself and get back with you. I do know that if you use 2 1/2 to 3 inches you will be ok. That is there is no metal inside the breaker box that is closer than that distance from the terminals. It mainly has to do with high voltage arc-over I believe, and not so much with lower votage DC, but at 250 amps if a short did happen I can tell you the metal box would turn bright orange to red in a matter of seconds. I have seen a 3/4 inch thick crow bar fall across a 2000 amp 48 volt telecom power distribution buss bars and the crow bar turned bright orange red within about four seconds. The person that did it, hit the crow bar with a 2 x 4 like he was swinging a baseball bat and the crow bar came loose and fell off before the buss bars went into melt down. Rememeber, saftey first, last bit of information, if you make your own breaker box and its not to code and or not UL approved, your home owners insurance may not cover your claim should there be an accident in which the breaker box is found to be the cause of the fire. If I were you I would do some research in this area before you make your own box.  FYI (arcandspark)