P1000 What do the relays do/provide/offer?

[sugarray]

As I am getting things together for my accessories and 2nd battery, I cannot get figured out why to have relays in the system with the PDM. I understand the isolator and how it works, as well as the PDM. Just don't understand what the relays really do. I have tried google searches, but can't really find anything other than what they are. I know they provide a break in the connection, but am having trouble understanding why this is needed.

Please help explain the role these play in the system. Thank you

 

[Admin]

 

[ohanacreek]

What PDM are you looking at?

Relays are used for controlling a large load with a smaller one and for circuit protection.

You can have (2) 300w light bars on your truck grill guard (40amps) on a 10gauge wire that is 6ft long with a relay at the battery and then control it from a light duty switch in the cab.
OR you have a 40amp switch which are hard to find, and a 6gauge wire (think cheap jumper cable) run into your cab.

the second option brings a lot of power a long way and increases the chance of a electrical fire or you can run a 18gauge wire from the switch to the relay and control the relay.

ALSO a winch contractor is a HEAVY HEAVY HEAVY duty polarity reversing relay controlled by a SPDT switch

 

[tjoreo]

Like ohanacreek said a relay is a great safety item. The headlights, ac and bigger items in your car/truck run off relays, while low current things like brake lights, car radios, and smaller items run off fuses. I had a little discussion with Jackal about relays and he said if it runs much more then 15 amps you would want to use a relay. He said a good rule is the size of wire. If the item comes with 14/16 gauge wire or smaller a fuse is adequate. Anything using 10/12 or larger wire needs a relay so you don't burn out the switch. Most guys using the relays are putting in big stereos, big led light bars and such. I think most of my accessories will be smaller items so I will just use a fuse block.

 

[sugarray]

I plan to use the universal PDM from Bussmann Jackal and others have used. I plan to have a Superwinch 4500, 2 rear facing 4" LED cubes, 2 forward facing 4" LED cubes, a red LED strip and white LED strip in the cab, 4 usb outlets. All run through switches. I plan to use an in/out switch for the winch. I'm trying to understand each link in the chain before I start putting it all together.

 

[tjoreo]

I have about the same plans for accessories in mind for my rig. I bought the same PDM that you are talking about but have sold it to another member on the forum. I sold it because with the accessories that you are talking about they are all low amperage devices that you can just us a fuse block. You can use the 15 amp fuses on the PDM and if you decide later to upgrade to bigger amp items, then you can use the relays for those items. If you look at Jackal's 1000 build he explains it pretty well what he is doing and using on his PDM. (Post #40 or so) The winch will not come off the PDM and will have to use the provided contactor "relay" that it came with. Hopefully that helps.

 

[sugarray]

It does, and I'll keep researching to get it straight in my mind. I don't ride a night, just in and out from hunting. The 4" cubes will be great for turning and to give extra light up front if needed. I like a red light while hunting, so running a strip around the roof will give me plenty to get my stuff out of the bed. Run a white one too when I'm not hunting. For $5-10 you have a lot of light. I have never thought would be nice to have a radio, so that really isn't an option. Big money will be on skids, roof, windshield.

 

[PioneerPete]

lots of good info on the internets...

 

[AK_Centurion]

I plan to use the universal PDM from Bussmann Jackal and others have used. I plan to have a Superwinch 4500, 2 rear facing 4" LED cubes, 2 forward facing 4" LED cubes, a red LED strip and white LED strip in the cab, 4 usb outlets. All run through switches. I plan to use an in/out switch for the winch. I'm trying to understand each link in the chain before I start putting it all together.

That Bussman PDM May be a bit overkill for your application. A 6-circuit fuse block should suffice. The winch will run through its contactor and each pair of cubes will be less than 5 amps, LED strips are low amp draw also, don't take much either.