new power max converter, problems
Replaced wfco 8955 converter with power max pm4b-55-mba converter. I put the new PM in today and followed the testing directions. Step 1. With only shore power hooked up and all DC fuses pulled ...
Forum Discussion
AFAIK, if the batteries are not up to 14.3 by the time the PM4 converter finishes its initial 15min of 14.6, then it will stay (or restart) at 14.6 until the batts get to 14.6. If the batts are to 14.3 it will drop to 13.6.
BUT the 14.3 is as seen by the converter, and as smk says, with the voltage drop, the converter "thinks" the batteries are higher in voltage than they are, so it drops to 13.6 when it shouldn't so soon, with the batts at 13.1
By morning the batts will be higher and amps lower so voltage drop will be small and you might think everything is fine. The trouble will come when you want to recharge by generator instead of shore power and it will take forever at mostly 13.6.
This is not unusual in an RV with the converter far from the batts. Fatter wiring might help. Or it might not reduce voltage drop enough, so another cure is needed. That cure is usually to move the converter closer to the batteries as a deck-mount. You can still do that with the open case lower portion if you have a sheltered enough spot to put it.
Or you can just leave that one there as is for your shore power converter, and get a second charger to use close to the batts for fast charging with the generator off grid. (That's what I did because rewiring the converter was too difficult for routing the wires, and 55 amps isn't many anyway. I use a 100 amper for fast charging)
BUT the 14.3 is as seen by the converter, and as smk says, with the voltage drop, the converter "thinks" the batteries are higher in voltage than they are, so it drops to 13.6 when it shouldn't so soon, with the batts at 13.1
By morning the batts will be higher and amps lower so voltage drop will be small and you might think everything is fine. The trouble will come when you want to recharge by generator instead of shore power and it will take forever at mostly 13.6.
This is not unusual in an RV with the converter far from the batts. Fatter wiring might help. Or it might not reduce voltage drop enough, so another cure is needed. That cure is usually to move the converter closer to the batteries as a deck-mount. You can still do that with the open case lower portion if you have a sheltered enough spot to put it.
Or you can just leave that one there as is for your shore power converter, and get a second charger to use close to the batts for fast charging with the generator off grid. (That's what I did because rewiring the converter was too difficult for routing the wires, and 55 amps isn't many anyway. I use a 100 amper for fast charging)
