Questions about My WFC 8725 Converter

[kayakrguy]

Hi folks,

I have some questions and I hope you can help me with the answers..

First, a fuse question

My WFC converter uses Littel 257 ATO fuses for the outgoing DC lines (3) and the battery circuit (1) In addition there is a fuse to protect against Reverse Battery mis-wiring

The 3 outgoingDC lines and the battery line take a maximum 25A fuse

The Reverse Battery protection fuse is a 30A fuse WHY the difference in fuse sizes? (BTW I intend to fuse my outgoing lines for 15 amps) I cannot understand why the reverse battery fuse isn't much smaller Amp rating than the regular circuits--seems counter-intuitive to me...

My second question is about wiring the unit to the battery. The white wire going to the battery negative is AWG 10. The red wire is AWG 12.
Now, most battery clamps and cables are #'s 2-6--MUCH bigger. So my question is: Do you use 2-6 and connect it to the # 10 & 12 AWG or do you spilce in a length of 10 and 12 to the connectors wire and use those to go to the battery terminals?

Thanks for any help you can offer...

Jim

[Greg M]

Presumably the reverse current protector carries the regular direction current when things are wired up correctly and then ,through a diode, shorts out when hooked up backwards. It would need to be a higher rating than the input fuse so that it doesn't blow before the input does.
As for the wiring; you should probably mount the convertor as close to the battery as possible, and use the existing wires. If you need to mount the convertor further away, I'd only increase the wiring by one size, and that's only if mounting several feet away. A #12 can handle a goodly amount of current.
The most important thing to remember though is to fuse within a foot of the battery for safety. There's nothing worse than having a short before the fuse, where it won't do anything to stop a fire.

-Greg

[kayakrguy]

Greg,

Thanks, what you said makes some sense re: the reverse polarity fuse.

As to battery-converter distance. The converter people say that the battery and converter should not be in the same compartment and the converter is not weather tight so should not be where there is moisture...so there will be some distance between the battery and converter. I may put the battery in the hatch, converter in the cabin and run connection through the bulkhead....

What would you suggest for battery (terminal0 clamps if I stay with 10 and 12 AWG to the battery?

Thanks, Jim

[bdosborn]

Jim,

What's the output current of your converter? That's how you pick the wire size.
20A=#12
30A=#10
40A=#8.

Edit: Oops, just reread your post and saw that you have a 25A output fuse. Use #10 wire.

If the distance is less than 6 feet you won't need to worry about voltage drop.
Bruce

[bledsoe3]

The converter people say that the battery and converter should not be in the same compartment
Thanks, Jim

My converter did not come with any directions. My battery is mounted next to my battery.

Did they say why they should not be mounted in the same compartment?

[kayakrguy]

Good Morning, Bruce and Greg....working on first cup of Joe...will try to make some sense

First, here's a pic of the converter face plate....



The AC breakers go on the left and the DC fuses go on the right.

Bruce, the warning simply says not to mount in the battery or LP Gas compartment, so battery gassing and Lp leaks and ignition is the reason for the warning.

Greg, the battery is a marine battery, so it has two sets of poles: one set like you see on your car battery and another set, threaded with wing nuts on them. Ideally I would like to have a closed ended connector on the battery but haven't seen any that would crimp on a #12 or #10 wire...but even the lug clamps that are held on with screw tensioners dont have connectors that would crimp on a #10 or #12...?

Bruce, that battery case is neat....it appears to be plastic....with the battery poles on the side? Where'd you get that? Also, your converter is in a case? ditto on question....

Thanks, guys..

Jim

[Sonetpro]

Jim, I have the same unit. I used 8 going to the battery. The battery protection fuse is also your main feed when the converter is not powered and you are runniing off the battery. On the circuit feeds fuse them according the the wire that you have on that circuit.
Radio shack should have the right connector for the wire battery connection.

I have a 25 amp feeding a sub fuse panel with all my 5 amp lighting circuits off of that. The others are fused at 10 amp. one going to the stereo. And one going to a 12V power point in the galley.

[kayakrguy]

Greg and Bruce,

I meant to ask another question....the converter people say that the Littel fuse type 257 ATO is the one to use...that's clear.

Now, the reverse polarity circuit is the only one that had a fuse in it when the converter came. It is 30 AMP but is called ATC, not ATO--what is an ATC fuse--how differenct from ATO?

[bledsoe3]

Jim, I assume you meant me and not Bruce. My converter is different than yours so I can't comment on the operation of yours. Here's the front of mine.

It's to the right of the battery box in the other picture. The box was given to me but I think you should be able to find one like at an auto parts store. It is plastic. The top is set to have the cables exit the ends or sides. It also has a strap that mounts to the floor and secures the battery in place. Just cause I already had it, I used 5 awg wire.

[Greg M]

The difference is between the blade type fuse and the round glass cylinder type. The manual is probably just out of date, so it's nothing to worry about.
On the connector question, you should be able to find a crimp on loop that is a large enough guage at an automotive store. They'll have them for big loads like winches. If that doesn't work try a car stereo installation place.

Good luck

-Greg

Greg and Bruce,

I meant to ask another question....the converter people say that the Littel fuse type 257 ATO is the one to use...that's clear.

Now, the reverse polarity circuit is the only one that had a fuse in it when the converter came. It is 30 AMP but is called ATC, not ATO--what is an ATC fuse--how differenct from ATO?

[Tripmaker]

Jim

As usual you are one step ahead of me and asked many of the same questions I had. For the circuits I used 14G and 15 amp fuses. I'm just running lights and the Fantastic fan so no big loads planned. I'm using 110 for the coffee pot. I don't know how you are laying out your galley but look at my album and see where I put the same converter you have. I wanted to be able to access the converter and fuses easily if necessary.

I was originally going to put the battery in the lower part of the galley seperate from the converter. However I am reconsidering this because putting the battery in a box it will make it difficult to access and service when necesary. I am also concerned about gas discharge building up. I can put a 3" round vent in that area. Is that enough? My other thought was to locate the battery on the tongue. Greg you make a good point about having a fuse near the battery, I hadn't thought about that. What size wire should I run to the battery with a 10' TD? I have about a 4' run from the converter to the lower galley using the 10 and 12 AWG supplied with the converter. Can I continue that another 12' or so to the tongue? If I go larger do I have to change the wire at the converter? Seems to me there would be no point in have a 8 gauge wire narrowing down to a 12 gauge at the converter as the smaller wire would be the limiting factor. Is that thinking correct?

The other Jim