2007 Power Converter

I took delivery of a 2007 2720SL today. The Power Converter is a World Friendship Company WF-8955AN. I googled it and came up with:

Product Name: WF-8955
Product Category: Converters - Power Center

55 amp switch mode power supply/charger with eleven 12 Vdc circuits with LED indicator lamps and reverse polarity protection, short circuit protection and over current protection. Available in Black or Brown case.

Don't have any idea whether this a step forward or backward from the units used in prior years but thought someone here might know...

Originally Posted by Tonopah

I took delivery of a 2007 2720SL today. The Power Converter is a World Friendship Company WF-8955AN. I googled it and came up with:

Product Name: WF-8955
Product Category: Converters - Power Center

55 amp switch mode power supply/charger with eleven 12 Vdc circuits with LED indicator lamps and reverse polarity protection, short circuit protection and over current protection. Available in Black or Brown case.

Don't have any idea whether this a step forward or backward from the units used in prior years but thought someone here might know...

In my opinion, if I had to buy a new converter, this would be the one I would buy. It has 3 phases, bulk, absorption, and float. If your battery is below a certain voltage, it will go into bulk mode and charge it at 55 amps. Between that voltage and a voltage a littler higher, it goes into absorption mode, which I think is like a trickle charge. Above that higher voltage, it floats, which I think means it is turned off, which means it will not boil over the battery for a real long time. The way it actually goes through all 3 phases is not as simple as I stated, but that is the basic idea.

I did research on this before I puchased our TM and I was relieved to see the WF-8955 installed. I would have replaced the converter if it were not a 3 phase.

Thank you for the info. We are currently on our maiden voyage with our 2720SL and thus far all is well. We happen to be in a park at the moment that has wireless.

Originally Posted by wboudx

In my opinion, if I had to buy a new converter, this would be the one I would buy. It has 3 phases, bulk, absorption, and float. If your battery is below a certain voltage, it will go into bulk mode and charge it at 55 amps.

How can a converter charge the TM battery at 55 amps when the fuse to the battery is rated at 30 amps?

This would require replacing the wires from the convert to the battery with heavier gauge wire and replacing the fuse with a fuse at least 60 amps and matched to the gauge of the wire.

Originally Posted by PopBeavers

How can a converter charge the TM battery at 55 amps when the fuse to the battery is rated at 30 amps?

My apologies. I was trying to keep it basic. Under opimum conditions, ie large wire etc., it would charge up to 55 amps. Considering the circuitry, wire gauge, distances, temperatures, level of battery charge, it could be conciderably less then 55 amp. I guess if the conditions are right, it could blow a 30 amp fuse going to the battery. All I know for sure, is it is a 55 amp charger.

The answer here is that the converter does not 'put out 55 A into the battery'. Instead, for a low charge on the battery, the converter probably puts out 14.4V and the battery takes whatever current it takes at 14.4V. I had that same question with my PD9160 which is a 60A converter. The highest current I have seen is about 35A when the battery was low.

[Bill]

Tonopah -

With your TM, did you get a worthwhile user's manual for the WF-8955? I sure would like to see one.

Does World Friendship Company have a website? I'm not finding much of anything on the web, and I would like to.

Bill

Bill:
My TM did not come with a WF-8955 manual. I did download one at this site.

http://www.bestconverter.com/assets/...8900manual.pdf

Rob

Thanks Rob. I have the same manual that came with the TM, and I downloaded another pdf file of the same thing, but was not that good. The pdf file you are refering to is much better.

I like to keep all these manuals on my PC.

After looking at the manual I downloaded, it does have one page different. Mine has the following for Automatic Microcontroller Operation


"5. Automatic Microcontroller Operation
Your WFCO power converter is equipped with a microcontroller
mounted on the converter's PC board. The microcontroller is ftilly automatic
and requires no additional equipment to operate. The microcontroller
continuously monitors the battery condition and determines what mode
(Bulk, Absorption or Float) the converter will be placed.


Below are the functions of microcontroller.
5-1 Our output voltage control microprocessor has been designed into the
converter PC board to avoid the need for additional equipment. When
power is initially applied to the power converter, the microcontroller
cycles through its modes to determine which mode it needs.
5-2 After the test cycle the power converter moves to the "Absorption Mode"
(1 3.6VDC)
5-3 When the output of the power converter is connected to the battery and a
load is applied (anything in the RV) the microcontroller checks to see
which mode the converter needs to be in.
5-3-1 If the output voltage of the battery drops to 13.2VDC, the power
converter automatically changes to "Bulk Charge Mode"(14.4VDC),
Normally, when the output voltage drops to 13.2 VDC it means that
the battery energy is less than 50%.
5-3-2 The bulk charge timeout period (time) is a maximum of 4 hours.
After 4 hours of bulk charge, the power converter changes back to
the absorption mode (13.6VDC). This is to avoid battery damaged
under a long period of bulk charge.
5-3-3 Under the "Bulk Charge Mode", when the microcontroller detects
the output voltage is at 14.4VDC, it will change back to absorption
mode even though the bulk charge period is less than 4 hours. This
is important to battery durability and battery life.
5-3-4 After a period of 48 hours of detecting no load or demand, the
microcontroller automatically places the converter in the "Float
Mode" (13.2VDC).
5-3-5 The design of the microcontroller is to "detect" the battery voltage
then "make a decision" to select the proper mode automatically.
5-3-6 CAUTION: If the converter cycles into the bulk charge mode more
than once during a charge cycle check the battery(s) to determine if
it has a bad cell."

Walt