WFCO inverter

[djmikel]

Hi All,

What are those two 40amp fuses for on the WFCO 8900 series. They are located between the big breakers for all the appliances and such and the 15 amp fuses for other systems. Thanks for the help.

[wilanddij]

If the WFCO is original equipment on your RV, 10 years is well beyond its MTBF. Get an equivalent PD model and have it ready for an R&R.

[BFL13]

Wild Card wrote:
and they work. My 1st rig before I knew RVs use Black as + and white as -, I was trouble shooting some issues (which turned out to be to small of wire) and hooked the batts up backwards. I let the magical smoke out.

For the DC side, you will also see red as pos with white as neg, and chargers with red as pos and black as neg. Some converters use blue as pos and white as neg.

[Wild_Card]

and they work. My 1st rig before I knew RVs use Black as + and white as -, I was trouble shooting some issues (which turned out to be to small of wire) and hooked the batts up backwards. I let the magical smoke out.

[road-runner]

The paralleled fuses are a higher rating than the converter's maximum output, so in theory the only way to blow them is hooking the converter to the battery backwards.

[djmikel]

Thanks all. Sorry for the incorrect terminology. And no....I don't plan to test them. 🙂

[BFL13]

The fuses are in parallel on the positive DC output terminal so they add their amps. There is a loose relationship between the rated amps "size" of the converter and the total amps of the RP fuses. Variations exist among brands and sizes within brands. Generally, the bigger the size, the higher the total amps of RP fuses.

EG, my PowerMax 100amper has four 40s, my 75 amper has three 40s, and my 55 amper has two 40s, but my Parallax 55 amper has two 30s.

[pianotuna]

They are reverse polarity fuses.

[time2roll]

Those are the main output fuses. Commonly known as reverse polarity fuses.
If you connect the battery in reverse the pair will open. Don't test it.

BTW the 8900 series is a converter. An inverter takes battery power and makes 120vac.