Hi guys,
I’m preparing to install an Airwire G3 with a lithium ion battery. It calls for a 10 amp fuse. Can I use a typical automotive fuse (which I assume is rated for 12 volts) or should I be using something else?
Thanks.
Yes Joe you can…a fuse is a fuse
Great! Thanks.
Well…
There are fast acting, Slo-blow and standard fuses.
But an automotive fuse should do the job just fine. Just as long as you use the proper current rating. In fact, on some of the automotive glass fuses, the rated voltage printed on them is not 12 VDC, but 120VAC. You need to look real close to see it.
In fact, there is a spade type, automotive fuse, in my Aristocraft Train Engineer.
I’ll be using a 14.8 volt battery pack so I figured a 12V 10 amp fuse is the way to go. I’m just guessing.
Joe Bussing said:
I’ll be using a 14.8 volt battery pack so I figured a 12V 10 amp fuse is the way to go. I’m just guessing.
Joe
Figured more of the experts would chime in on this one. However I can tell you once again that you will be just fine. Without going into technicalities and all the expert advise that may come with your post. If you really want to get anal then figure out the amperage your locomotive will pull in maximum operation conditions and set the fuse at that specification. Say 5.5 amp automotive blade type fuse. You could even go to the mini or micros if you wish.
If the fuse doesn’t blow then the battery will and the Lio On batteries will take out the entire west coast if they blow when not fused properly.
It’s all good and all you want to do is run your new locomotive which we want to see as we love pictures here!
(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)
10 amp and 12 volt. That’s my story and I’m sticking to it!
It’s all good Joe !
Just do it and post pics or video of the new unit !
Will do!
Fuses I have seen for auto were 32 volts.
I would go with the fast blow fuse every time as electronics can burn up before any slow blow fuse reacts.
Dan has the right of it. A fuse’s VOLTAGE rating should ALWAYS be higher than what you are going to see.under normal operating conditions. The logic for this is that the voltage is what will jump across the gap, not the amperage. And a fast blow fuse may be replaced more often, but is usually far less expensive than the electronics it is there to protect.
After a bit of reading, I agree that the fuse voltage should be higher than the system voltage. The fuse still blows at the stated limit (10 amps) but the higher fuse voltage eliminates the possibility of the current arcing in the fuse and still burning up your system. A typical 32V auto fuse would be fine.
I think…
you do not size a fuse by the constant current you want to run, but where you want it to blow. Typical fuses blow at 200% of the rating, so a 10 amp fuse will blow at 20 amps…
So in this case, a 10 amp fuse is not much protection.
Greg
Greg, yes, but that is what was called for in the specs.
The 10 amp fuse here to protect the G3. On my older installs I used 5 amp slo blow in most of my installs.I have been using 6 amp resettable poly fuses in my newer installs. The reason for the lower value is to more closely monitor the motor current draw.
Side note… Automobiles do not use 12 volt fuses as when running the voltage output of the alternator is over 14 volts and the battery is really 12.6 volts when the engine is off. In order to charge the battery a higher voltage is needed and can be 13.8 to 14.4 volts therefore anything added to a cars electrical system must be rated for that voltage or higher!!!
So, lead acid batteries have created an industry standard. 3 cells in series are 6.3 volts and 6 in series gives 12.6 volts. These are the filament values for vaccuum tubes as they were first used with batteries!!
Now rechargeable batteries create new voltage standards.