More Voltage Reducer questions

[zephyrus]

Hello all,

I recently bought Scotty B's 30 amp voltage reducer for my 2007 CC DS IQ cart. I have wired it as per the diagram that came with it. I have pack 48V hot going to the reducer on the red wire. I am using the 48V "cold" keyswitch terminal to turn the reducer on with the key switch at the yellow wire on the reducer. I have verified that the key switch is sending out 48V when it is in the on position, and is not when off.

I am wiring the 12V output to a fuse block with separate circuits for my 12V LED light bar and cigarette lighter adapter/USB phone charging adapter.

I have a ground buss that I have run to pack negative. If I go to hook the reducer to pack negative I get a pretty good spark. The voltage reducer is not currently connected to the negative side of the battery pack.

What has confused me is that when I was wiring the 48V hot, red wire, from the battery pack to the voltage reducer, I received a mild shock because I was touching the seat bracket at the front of the battery compartment. This is one of the 2 slots that the seat bottom cushion fits into.

After that happened, I began to make voltage checks with my meter, and found that I have 45V between pack positive and this seat bracket. I was under the impression that nothing should be grounded to the frame. I should add that the Run/Tow switch is in Tow.

I get Meg Ohms when I test for continuity between the seat bracket and pack negative.

I also made a voltage check between the green output wire of the voltage reducer and pack ground and saw 30V with only the 48V unswitched hot wire connected. Currently, this is the only wire connected to the reducer.

I have stopped work on this until I can get this sorted out. I have double and triple checked my wiring that I have done on this reducer.

I have not intentionally grounded anything to the frame. It is however, a "refurbished" unit allegedly from Club Car. That is what I was told when I bought the cart from a local Club Car dealer.

Any help on this will be greatly appreciated.

[Sergio]

If You have a working OBC you should not run your "ground bus" to pack negative.

You should have a connection off the Controller B- for the accessories negative power.

This is necessary so the OBC can measure the current being used by your converter.

The spark you saw is normal and the result of the converter discharged capacitors receiving power.

You need to use a resistance in series with the converter negative wire before connecting it directly to the negative source.

You can use a regular incandescent light bulb (40w or 60w).

Touch the bulb base to the negative source and the wire from the converter to the bulb threads.

Wait 10 seconds and you can then connect the wire directly to the negative source without sparks.

The voltage you measured to that bracket is typically caused by a digital multi-meter with a high impedance input.

It only takes 0.0000045A for a 10MΩ multi-meter to register 45v.

[SouthCo]

Great info Sergio, I followed the directions my reducer came with but they didn't mention putting the ground to the controller B-. I'll have to fix that.

Where should the reducer ground be wired to if the OBC has been bypassed/removed? The pack negative or still the controller B-?

Thank you

[Sergio]

If You are not using the OBC then you can connect it directly to the pack negative battery post.

Just as a reminder, the main cable lug should always go first and in direct contact with the battery lead pad.

Any additional wires would go on top of the main cable lug.

[REDSLED]

Just cause ill be doing this on my CC pres very soon. If you have a OBC you need to connect (-) to black wire coming from OBC? It is in battery compartment, it currently has the ground to my light kit connected to it.

[REDSLED]

Ill be using the madjax reducer, the instructions tell you to go to the (-) on batt pack. They don't state any specifics for certain carts.

[Ken taylor]

The accessories that use the 12volts from converter do they have to be pulled from the b- terminal also or can you use the main negative at battery post .

[Sergio]

If You are using the OBC to charge the cart, only the pack negative cable should be connected to the pack negative battery post.

The Precedent carts have a a 12ga black wire with a yellow female bullet connector inside the battery compartment that comes from Controller B- that is used for any accessory connections.

Club car DS models usually have a negative connection block off the Controller B- that is used for accessories negative connection.

All individual accessories negative wires usually terminate on a common bus and a single wire goes back to the Controller B- using the wires described above.

If your DC converter is not Isolated (most are not), the converter negative wires (48v and 12v side) will also terminate on the same common connection bus as the accessories.

[REDSLED]

I was under the impression that everything is to be grounded (B-) from the controller and then have a (-) bus bar for accessories, just as you would have a (+) bus bar / fuse panel off reducer.

[REDSLED]

Ahh, thank you for the clarification. Sergio, you are truly the master of the CC Pres.