Adding a relay to lower the amperage on a switch?

What this means is that the electric contacts in your switches are rated for a maximum of 15 amps. You can purchase a relay that is rated for higher amps. In that case, the switch would only activate the relay. The relay would act as the switch for the heavy amp draw item. I would think you could find a relay at an auto parts store. They come in many amp ratings. Hope this helps.

qwerty11 wrote:
I have these switches that are rated for 15 amps. The instructions say I can add a relay if I need to connect something that is over 15 amps. Could somebody help me understand what this means and link me to the relay I need for say a 30 amp load?

Thanks!

It means you need to add the relay(electrically operated sw.) between the source of electricity and the load. The original sw. then operates the relay. This is one of those things that is hard to explain in a forum when you may not be a little familiar with the workings electricity. If it me I would go to the nearest electrical wholesaler,not big box store, and talk to them. They can help you as well as a contractor. Hope this helps a little.

Yes it means exactly what you said. The relay will carry the load instead of the switch.

Ok. So if I have a fuse panel for the individual circuits and want to wire up a master kill switch (that is rated for 15A), I need to have the relay in-line with the positive wire coming from the battery. The relay will be connected to the switch. The switch will trigger the relay allowing power to flow to the fuse board and energize my system. Does that sound right?

Does the relay and master kill switch need to have a fuse sense it will be before my fuse board?

Here is a post I did on IRV2 showing a switch and relay to power a 40 Amp fuse in my Saturn.


http://www.irv2.com/forums/f85/fuse-removal-hassle-on-saturn-outlook-94913.html

Qwerty11

If you are trying to isolate the battery then a Battery Isolation Solenoid is what you would employ vs a relay. Tow Ready 118665 Battery Isolation Solenoid Trailer RV Camper would be an example.

SCClockDr wrote:
Qwerty11

If you are trying to isolate the battery then a Battery Isolation Solenoid is what you would employ vs a relay. Tow Ready 118665 Battery Isolation Solenoid Trailer RV Camper would be an example.

I'm just wanting a master kill switch for my 12v system. I would like to use the switch I already have. Thats why I thought the relay/switch would be the best bet.

I must have missed somehow whether this is for AC or DC

No matter what, you can think of a switch as a bartender. The load being an obnoxious drunk.

The bartender calls over to the bouncer (relay)...

"Take care of this will ya"

The switch did not have to work very hard, did it?

After fighting bargain DC relays for too many years, never again will I buy anything other than a TYCO which is the new name for the BOSCH 30-amp DC relay. The dollar ninety-nine relays which look like a TYCO are junk. The TYCO relay is made better, out of heavier duty components, is environmentally sealed, and does not get as hot as it's competitive garbage. Get This: Bargain relays in a bone-dry desert environment. 10-months after purchase. Failed to operate cooling fan on radiator. Opened them up to find a mound of rust inside. No possible way they got wet. Some form of weird electrolysis. So I TESTED f-o-u-r UNUSED different manufacture "Bosch Type" relays for power contact volt drop. Har Har Har Har! At thirty amps load it was a cruel joke. The worst was 2.15 volts drop. The "best" of the counterfeits was .88 volt drop.

sorry
you need a 'latching' relay that is operated by a momentary push button

a regular relay uses power when activated
using it means it will draw power when activated

so if your kill switch is wired to activate the relay , to break/disconnect the circuit in storage it becomes the load and drsins the battery

if wired so normally disconnected and only connects when turned on, it bevomes an extra loa drawing power even though all lights etc are turned off

you need either a latching relay, which only draws power when opening or closing and then latches/locks in position
or
you need a manual battery disconnect switch mounted at the batteries

In what I think is simpler terms:
when you add a relay, the relay becomes the heavy duty switch needed to operate the load.
The switch now only operates the relay. Tells the relay when to turn on and off which in turn now turns the accessory on and off.