Voltage Reducer Wiring (Cross-Post)

[Rodie]

Cross-posting into EZGO Electric hoping to find someone knowledgeable. No responses over at Yamaha! Thanks all --

I'm hoping someone smarter than I can check my work before I begin this install. Here are the details:
2007 Yamaha Drive/Electric 48V (4x12V)
48V->12V Reducer that does not have a switched wire (always on)
Bank of four switches (see picture)
Potter & Brumfield T9Ap1D52 Relay

Basically, I want to use one of the four switches to turn the reducer (and everything attached to it) on and off all at once. The other three switches would be to control the three 12V accessories at the end of the reducer on and off individually (lights, radio, and voltmeter.)

I attached an image of what I perceive to be the correct wiring for this but am looking for someone (scottyb?) to confirm I'm on the right track or set me straight before I go much further. Some of my specific concerns:
Most using the relay are connecting to the cart's ignition switch (to switch on and off the relay) which I believe would be 48V. I would like to hook that end of it to 12V so I don't burn up my cheaper switch (don't ask me how I know the switch can't take 48V!) My impression is that you can use about any voltage on this end to switch the relay. Is that the case? Obviously, the other connections that are actually passing the power through would be 48V.
You'll notice I am coming off one battery for 12V (before switch 1) and the last battery for 48V (to the relay) but I have everything sharing the same ground. Can I share the same ground for both the 12V and 48V traffic?
Anything else look amiss?

Here are the images -- THANKS in advance. This community is great.

[orangeman6]

Hey Rodie, you're wiring your reducer similar to how I did mine. I wanted to be able to turn it on/off, and control all accessories, without the key switch. I think you're pretty close on your diagram, but I'm far from an expert. I would search the ezgo forum for Sergio's posts on wiring a reducer. He's posted some diagrams that are exactly what you need. In the meantime, I do have a couple of thoughts on your setup.

You need to make sure you get the correct relay. You're going to trigger it with 12v, so it needs to have a 12v coil. Also, it will be passing all of the amperage of your accessories through it, so it has to have contacts properly rated.

You will have a fuse block, not a bus bar for your positive 12v. Each accessory will have its own fused power wire coming from that block. Do not run one 12v+ and branch off for each accessory. 12v out from the reducer, to a fuse block, then out to each accessory with its own separate +.

You can have a bus bar for your -. I ran the - for arch accessory back to the bus bar, but someone else will have to confirm best practice.

Here's a great place to source relays, etc.

http://www.mouser.com/m_Home.aspx?gc...4eZhoCKfjw_wcB

[Rodie]

Thanks orangeman -- I think I need a new relay and will get the fuse block!!

[orangeman6]

I know you can't tell wiring specifics from this pic, but here's a shot of my reducer setup. You can see the relay at the top. The fuse block is below that, then you can see the -bus bar below that.

Again, if you haven't already, I would find the posts by Sergio just to review and educate yourself. I'm triggering the 12v coil with two of my 6v batteries. At some point I'll be going to 6 8v or a lithium pack. When I do that, I'm going to have to change my setup. Pingeye has been helping me with how to make that happen and he is very knowledgeable as well. I'm not sure if he's posted on the forum regarding reducer setup but he is definitely worth searching.

Good luck, and be sure to post your plan before you start wiring so you can get more feedback.

[yurtle]

I'm assuming your reducer doesn't have an "on" wire? You can buy a relay for any voltage coil you want. No problem with 36 volt, 48 volt, 60 volt, etc. A 12 volt coil isn't the best way to do this, but it probably pulls a fairly low amperage.

[bronsonj]

On your 12v circuit you have both 12v positive and ground going to the switch and the switch then feeds positive 12v to the relay. What's the purpose of the ground? If it's a toggle switch you'll probably just have a single input and single out, no ground connection. Unless it needs the ground for the LED or some such.

Also, you asked if you could use a common ground for your 12v and 48v circuits. The answer is 'Yes, but...'

Do not connect the ground to the cart frame. You don't want to mix grounds with the 48v controller/motor. The purpose is to not pick up electrical noise from the motor and controller.

[yurtle]

I may have misunderstood the post. I assumed he wanted to turn on the reducer with a relay, which can be accomplished by any voltage relay coil. If this is not the case, there's no need for a 12 volt relay, unless the reducer is always on, which I wouldn't recommend.

[Raystar57]

Originally Posted by bronsonj

On your 12v circuit you have both 12v positive and ground going to the switch and the switch then feeds positive 12v to the relay. What's the purpose of the ground? If it's a toggle switch you'll probably just have a single input and single out, no ground connection. Unless it needs the ground for the LED or some such.

Also, you asked if you could use a common ground for your 12v and 48v circuits. The answer is 'Yes, but...'

Do not connect the ground to the cart frame. You don't want to mix grounds with the 48v controller/motor. The purpose is to not pick up electrical noise from the motor and controller.

Yep, it looks like a lighted switch unit and he is using switch #1 to control the relay.
Needs the ground for the LED's.