Fussing over Fusing

[kayakrguy]

Folks,

I understand that safety dictates that the fuses used on a circuit must NOT exceed the capacities of the smallest wire in the circuit/and or the smallest load on the circuit. Now, here are the questions I have:

My Fantastic Vent came with no literature. Can anyone tell me what the amperage is of the motor and the capacity of the wires sticking out from it?

Also, the LED lights I have draw low amperage but I have no idea what the capacity of the wires with some of them can carry....

Would appreciate info about the FVent and how to determine wire capacity on things like lights.

Many thanks to all,

Jim

[Sonetpro]

http://www.powerstream.com/Wire_Size.htm

[asianflava]

I measured the current draw of my fantastic fan but my CRS kicked in and I can't remember what it was. I'm thinking that was 3A (on high) but I don't know for shure.

[Steve Frederick]

My Fantastic Fan has a 4-Amp fuse in it...I ran 14-ga cable everywhere.
Fuse that one at 5-amps.

[kayakrguy]

Steve and Steve,

Thank you for the chart and reminder about the FV fuse. I checked ours and yes, it has a 4 amp fuse and 16 guage wire. I looked at it! (thought it should have paper work with it, though) Since the motor is protected by its own 4 amp fuse, would it be ok to wire the FV into a 15 amp circuit? Somewhere I recall that motors should NOT be fused with a fuse with larger capacity than the motor...in case motor freezes, continues to run, overheats etc....

But, with its own fuse, the motor can isolate from the circuit it is wired to in case of an overload or freeze--right? Or should I play safe and just put the motor on its own circuit??

Jim

[Ken A Hood]

http://www.fantasticvent.com/faq/knowle ... nuals.html

Here's a link to their manuals.

[Dale M.]

Steve and Steve,

Thank you for the chart and reminder about the FV fuse. I checked ours and yes, it has a 4 amp fuse and 16 guage wire. I looked at it! (thought it should have paper work with it, though) Since the motor is protected by its own 4 amp fuse, would it be ok to wire the FV into a 15 amp circuit? Somewhere I recall that motors should NOT be fused with a fuse with larger capacity than the motor...in case motor freezes, continues to run, overheats etc....

But, with its own fuse, the motor can isolate from the circuit it is wired to in case of an overload or freeze--right? Or should I play safe and just put the motor on its own circuit??

Jim

You are not just protecting the fan when you fuse it at 15 amp... You are protecting all the wire from fuse to device.... The 4 amp fuse in fan just protects the fan.... If you have a short in wiring between fuse and fan, 15 amp should be ok....

I am intending to fuse every line in my TD with same size fuse (maybe 10 amp) no matter what it supplies unless I specifically have appliance that draws more than that.... Sort of like the circuit breaker theory in homes... most breakers (in homes) are either 15 or 20 amp capable even if they only actually draw 1.5 amps or whatever...

Also so plan to use same gauge wire all through out construction ( probably 12 gauge) so I don't have any restrictions once wiring is in place and no longer accessible...

Considet this... What if you replace fantastic fan with something else later any you find wire gauge too small.....

Dale

[kayakrguy]

Ken,

Thanks for the specs stuff...it confirmed 'flava's memory that the FV draws three amps on the 'Hi" setting...

Dale,

I'm with you on the 12 or 10 wiring throughout. BUT since the fan has 16 gauge wire, that creates the problem--given a run to and from the fan of about 16'--that a heavier wire could overload the 16 guage wire...I have to fuse for the 16 gauge wire, not a larger wire, on that particular circuit.

I was hoping to fuse circuits at 15 amps for purposes of both safety and flexibility--so I can add on later, if necessary.

Thank you, guys,

Jim

[madjack]

Jim, we used 14ga wire for all 12v stuff and fused everything with 10a fuses...................................

[kayakrguy]

MJ,

You know, for all practical purposes I probably could do 14 ga wire just fine.
I don't plan on more than 3-4 circuits with one of those only for receptacles.
I begin to worry about the issue of campground supplies running 30/50 amps and having only 10/15 amp fuses....is there a way to 'step down' the campground supply?

Jim

[madjack]

Jim, the 30/50amps from the campground is what is available...the power is pulled from that supply as needed...it does not flow that amperage at all time....think of it as a 500 gallon water tank...you "dip" out what you need as you need it, otherwise, it just sits in the tankwaiting untill needed...electricity is "pulled" by the appliances...not "pushed" by the mains.........
madjack

[SkipperSue]

electricity is "pulled" by the appliances...not "pushed" by the mains.........

Well said Madjack!

[Elumia]

and a short circuit will pull as much juice as is in the barrel, hence the need for circuit protection!

Mark

[kayakrguy]

My bad, guys--I mixed apples and oranges--dc and ac-- in my question about the campground supply (ac) and 10-15 amp fuses (dc ) My garbled 'step down' was looking for the device that converts the 30-50 amps of ac to the dc you need for the 12 volt system. I want to use the term transfomer but I know that's not it????

Which leads me to a side question--I have an old, but still good' Sears battery charger--a 10-2 two step--would that be ok for charging a deep cycle or do you need a three step for that purpose? I realize that the wrong kind of charging will beat up a deep cycle and I sure don't want to throw $$$$$$ away like that!

Hope I cleared up the confusion I caused. I liked the push/pull description, too <g>

Jim

[asianflava]

Converter= AC into DC
Inverter = DC into AC

You are correct that a transformer will "Step it down" but it will still be AC.