12 Volt power loss

[frodus]

No.
Spade 2 goes to the output of the keys switch. The input of the key switch needs to be fused for a few amps and hook to B+.

Spade 1 goes to pack ground

Spade 3 goes to anode

Spade 4 goes to cathode

The DC to DC positive, pin 1 connection and controller B+ go to the output contact of the contactor.

B+ Goes to the input contact of the coontactor.

[rob5456]

Thanks, from this set up the key switch is only powered from B+, and only have power via the pre charge resistor? Is that enough to (after the key is turned) fire the contactor?

IMG_20120412_172840.jpg

[frodus]

Here

[rob5456]

My 10A fues keeps blowing, do I have a problem with my contactor? Do I need to lower the amperage before the fuse and switch? Here is a simplified drawing of my new situation.IMG_20120414_120722.jpg

[billmi]

What is the max voltage rating of the fuse (though I wouldn't think that should matter, voltage rating only deals with possibility of arcing once it's blown, I thought)?

What's the amp rating of the fuse? How many amps does the contactor coil draw on inrush and how many for holding?

What is the diode connected to? Typically a diode is run across the terminals of the coil to short out backwash from the collapsing magnetic field in the coil, but it looks like you have it on different terminals than those supplying power to the coil.

Anything else there in the circuit we're not seeing?

[rob5456]

250V, 10A Fuse

I use the 72 Volt SW-180 Contactor with 3 Amp Diode and 1000 ohm Resistor, I don't know the draw

I think the contacts (on the same sides) are linked, I will check for continuity. But I also connected them together so they were on the same spade, not just the same side.

Nothing else is in that circuit, I have worked down to the bare minimums to determine the problem.

[magicsmoke]

In your last drawing, just swap the B- and the diode Cathode (the banded end).
This is because I'm pretty sure that the four coil terminals are in two pairs which are shorted across the body not in line and so every time you've thrown the switch you've simply shorted the battery via the switch/fuse.

good luck
Rob

[billmi]

You nailed it MagicSmoke.

Here's the datasheet:
http://pdf.directindustry.com/pdf/al...916-67224.html

"Coil connections are by 6mm spades of which two are supplied per terminal"

The line to B- on the controller and the line from the keyswitch are connected to the same terminal, creating a short circuit.

[rob5456]

Bingo Bango! thanks!