Electrical Question

[rleathen]

Many have stated that when hooking up auxiliary electrical equipment (i.e. lights, cooling fans) that they should be powered through a switched relay. My question is this.....if I have an electrical accessory that draws, say 6 amps, do I really need to power it through a switch controlled relay instead of through a switch that is rated at, say 15 amps. In other words what is the benefit of using the switch to control the relay and hence power to the accessory as opposed to just supplying power to the accessory just through the switch alone ?

Thanks in advance.

[WackyDan]

The relay is there if you power the accessory off of a sensitive circuit or if you want to only have power available when the bike is running. The relay draws far less than that of the accessory in order to switch the load directly to the battery and keep the computer happy.

If you just need 12v, then by all means run the wiring straight to the battery and ensure you properly fuse it. That will leave the switch "hot" at all times, and you could forget to turn it off, and drain your battery... or someone monkeys around with your Spyder due to curiosity and drain your battery for you.

[Stuart49]

On the other hand, you may want this accessory outlet HOT all the time. I have two additional powered feeds from the battery connections (under the seat), one for my GPS, which I want to have on all the time when I'm on a ride, and the other for a powerlet outlet by my left foot (see attached photo) for charging the battery and to power my heated gear. Both feeds run thru fuses located conveniently under the seat.

Stuart

[NancysToy]

Many have stated that when hooking up auxiliary electrical equipment (i.e. lights, cooling fans) that they should be powered through a switched relay. My question is this.....if I have an electrical accessory that draws, say 6 amps, do I really need to power it through a switch controlled relay instead of through a switch that is rated at, say 15 amps. In other words what is the benefit of using the switch to control the relay and hence power to the accessory as opposed to just supplying power to the accessory just through the switch alone ?

Thanks in advance.

The primary benefit to using a switched relay is that you do not need to remember to turn off the switch every time you use the accessory. Forget just once, and you will run your battery down if you connect directly. That could leave you stranded somewhere. It is real easy to install an auxiliary fuse block and a relay, so that you can run any number of switched accesories easily. If the fuse block is up front, the wiring is shorter and easier, too, without need to remove the Tupperware each time.
-Scotty

[rleathen]

OK I have a switched accessory fuse box (powerbus). The question then is can I run, say auxilary lighting, directly through a switch connected to this fuse box or would it be better to use the switch off of this fuse box to control a relay to control power to the aux lighting directly from the battery.

In more simple terms if I have a switched source of power is there any benefit to power the accesory lighting via a relay as opposed to powering the acc. lighting directly through a switch connected to the switched source of power.

Thanks again and sorry for such a convoluted question.

[Big Arm]

OK I have a switched accessory fuse box (powerbus). The question then is can I run, say auxilary lighting, directly through a switch connected to this fuse box or would it be better to use the switch off of this fuse box to control a relay to control power to the aux lighting directly from the battery.

In more simple terms if I have a switched source of power is there any benefit to power the accesory lighting via a relay as opposed to powering the acc. lighting directly through a switch connected to the switched source of power.

Thanks again and sorry for such a convoluted question.

IMHO, I'd say you could run your aux lighting directly from your switch, fed from your fuse box. If your lighting load was excessive, (more amps than the sw or wire were rated for) then I'd use the relay.

[sabunim5]

IMHO, I'd say you could run your aux lighting directly from your switch, fed from your fuse box. If your lighting load was excessive, (more amps than the sw or wire were rated for) then I'd use the relay.

+1

[NancysToy]

OK I have a switched accessory fuse box (powerbus). The question then is can I run, say auxilary lighting, directly through a switch connected to this fuse box or would it be better to use the switch off of this fuse box to control a relay to control power to the aux lighting directly from the battery.

In more simple terms if I have a switched source of power is there any benefit to power the accesory lighting via a relay as opposed to powering the acc. lighting directly through a switch connected to the switched source of power.

Thanks again and sorry for such a convoluted question.

It pretty much depends on the amount of current the lighting draws. Headlights and other lights with a large draw are generally run via a relay, since many switches do not have a sufficient amp rating to carry the lighting load (plus a safety factor). You can run a 30 amp or better load through a relay, if need be, but are unlikely to find many switches that would carry that load directly. For lesser lighting loads, a switch alone may be sufficient. Just make sure the fuse on the circuit is sized correctly, and the wire and switch are of sufficient capacity. I would not cut it too close. For instance, two 55W bulbs is a 110W load, which for 12 volts is 9.2 amps. Allowing a safety factor of 25% means the circuit would have to be capable of handling 11.5 amps. A standard 10 amp switch won't cut it!
-Scotty

[rleathen]

Thanks to all who replied. For my acc. lighting which will draw about 9.2 amps as per Scotty I do have a 15amp rated switch so I think that is the way I am going to go.