17' Series Setec Unit

The best and most accurate way is to turn everything on and pull each fuse in turn or power each circuit up individually and see, if you have disconnected it all just use a simple jumper lead ................. With Jayco not always labelling things correctly another van may not match yours.. The HWS/Pump fuse may just be empty circuits so could be handy to track for add ons.

Drover: So true. When my Jayco arrived from the factory, my memory may have dimmed a little since, but I seem to recall that only 2 or 3 of the 8 SETEC fuses were correctly labeled. I had to go through that exercise of turning everything ON and then pulling the fuses one by one to identify what each fuse was connected to.

garfield28 said:

Hi all,

I am pulling out my setec Unit as I do not use the battery charging aspect of it, so it has no use other than that.

My question for anyone that knows, for some reason mine has a fuse installed and cables that state HWS and water pump etc, but I don't have those options installed on my van.

Also, anyone have some advice for how I can check what the cables I have disconnected actually are even for please? I have a basic model 2010 Jayco Expanda so not sure why I have so many cables when basically I really on have the bed end lights, the ceiling lights, and the lights outside the door and under the awning.

Anyy advice much appreciated.

Thanks
Geoff

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Don't forget @garfield28 that the Setec also acts as a power distribution device for all the 12 volt power circuits. Although you may not use the Setec for charging a battery, other 12 volt circuits including lights, (inside and out), water pump, bed lights etc are all distributed via the Setec -hence the various fuses. All 240 volt circuits are wired separate to any 12 volt systems. So whilst you may not use or want to use the 240 volt/12 volt charging system in the Setec, unless you want to rewire all the different 12 volt circuits , you will need to keep the Setec. Just disconnect the 240 volt AC plug to the Setec and leave it at that. A different/better?? charging system can be connected directly to the battery from the 240 volt AC socket and not through the Setec unit.

Also note what @Drover said about labeling and circuit connections as labelling is often incorrect.

Many have fitted better BMS units to charge their batteries especially for AGM's and Lithiums but they kept the Setek unit as the 12v distribution system/fuse block for their 12v lights etc, this is achieved by unplugging the 240 mains, in fact you could cut the lead off, so long as its connected to the battery as originally it will power all your 12v lighting as before, to change it would be as Boots described and you would end up with the same thing, just a fancy fuse board....

The SETEC ST35 III unit that came with my 2016 Jayco has 3 functions
1. It has a 240V AC input lead that passes power to a stepdown transformer to provide 12v DC
2. The 12v DC is then passed (a) to the included battery charger to enable the house battery to be charged, and
(b) to the 12v distribution panel (and its associated fuse box) to power the lights, water pump, frig control panel, stove igniter, radio, tv etc.

However, the included battery charger is a sub-optimal unit and doesn't really provide a high enough voltage to fully charge a GEL or AGM battery. It is also not lithium battery compatible.

For that reason, many (myself included) prefer to charge the house battery using a separate, more appropriate battery charger. The easiest way to inhibit the builtin SETEC battery charger is to remove the 240V 3-pin plug. However doing so also disables the stepdown transformer so that it can no longer provide 12v DC. With an installed house battery, that is not a problem because the SETEC remains connected to the house battery and that battery is able to provide power to all the appliances connected to the distribution side of the SETEC unit. The great advantage of leaving the SETEC in place is that its 12v DC distribution and fuse box can be continued to be used with no re-wiring changes needed. Just be sure to label the removed 240v 3-pin plug with a DO NOT USE label.

@BaldEd has described it exactly ...............................

So if you have fitted a better charger to your rig then just leave the Setek unplugged from mains but connected to your battery and everything will work, your new charger will charge the battery be it solar or mains feed and the Setek will feed all your lights ..........

Now if you want to fit a monitor gadget then the Setek battery cable just connects to the shunt as per normal, taps in on van side of shunt and whatever display you have will show up the info on power draw ... The Setek won't have anything to do with charging anymore and won't cause any drama with another charger and you get to keep your fuse board.