Replacing a WF-8735P with a PD4135KW2BV

I’m in the process of making the subject power center swap to support full charging of a LiFePO4 battery in my R-Pod 196. I went with the PD power center because it has a swappable converter section whereas the WFCO WF-8735P does not, making future repairs easier.

I’m confused by the 30A “battery fuse” circuit in the WFCO. It’s on the same wire as the DC input voltage into the unit. The label on the door of the unit says, “30 A Bat, Refer Elem, Awning” but since it’s on the same circuit connected to the battery, how does it actually provide protection for those devices? Does it just provide converter overcurrent protection, i.e. is it connected to the converter DC circuit internally? I can’t find any schematic detailed enough to explain it.

The PD unit doesn’t have a dedicated “battery” fuse slot. All circuits except for reverse polarity are defined as branch circuits in the PD documentation. Do I need to worry about that extra 30A fuse?

There’s a 40A reverse polarity fuse in both the WFCO and PD panels. The difference is that there’s another 30A fuse connected to the panel’s +12V power feed on the WFCO. The 12V power wiring in the 196 is on 8AWG wire coming to the panel.

I didn’t realize until you mentioned a 3-way fridge that the 196 has a 2-way fridge, so the part of the circuit description for the refrigerator element is not applicable for the installed fridge.

The problem with using an inline fuse is that the awning motor is apparently wired directly into the 8AWG battery feed upstream from the panel.

I ohmed out the fuse board on the WFCO panel and discovered that the “battery” fuse is wired between the voltage input/output and the branch circuits. In that location, it would provide battery charge overcurrent protection as well as being a master fuse for the branch circuits. I suspect the converter section on the PD panel is internally fused so that the “battery” fuse is not needed. In any case, it most certainly does not protect the awning motor circuit.

I got the swap done except for the mounting screws. It turns out that the PD power center is 1/2” narrower than the WFCO and there’s really not enough wood to do new screw holes. So, I’m going to cheat it to one side and use some metal tabs to “extend” the mounting holes on the other side. The more I work with this, the more I know PD is stretching the truth when they say it’s a direct replacement for the WFCO. On a positive note, the battery had charged up to 14.7V by the time I left storage. I left it charging so that maybe it’ll balance the cells.