WFCO WF-8950L2-MBA User manual

Operator’s Manual
Distributed in the U.S.A. and Canada by
ARTERRA DISTRIBUTION
[phone]
Warranty: [email protected]
Fax [phone]
www.wfcoelectronics.com Power PROs Technical Support
[phone]
WF-9900 Series
Replacement Lithium-Ion Converter-Charger Main Board Assembly
WF-8950L2-MBA

SAFETY INFORMATION ........................................................................................................... 3
GENERAL INFORMATION
Reverse Battery Protection ........................................................................................................... 3
Automatic Cooling Fan ................................................................................................................ 4
Over-Temperature Protection ...................................................................................................... 4
Electronic Current Limiting ......................................................................................................... 4
Short Circuit Protection ............................................................................................................... 4
CIRCUIT PROTECTION
DC Fuses ......................................................................................................................................... 5
OPERATIONAL FEATURES
Two Stage Smart Charging ........................................................................................................... 5
Converter Modes of Operation ....................................................................................................5
Bulk Mode ...................................................................................................................................... 6
Absorption Mode .......................................................................................................................... 6
TROUBLESHOOTING INSTRUCTIONS
Converter Output Voltage ............................................................................................................. 6
Troubleshooting Flow Chart ......................................................................................................... 7
INSTALLATION INSTRUCTIONS
Replacing the Unit .......................................................................................................................... 7
GENERAL COMPLIANCE INFORMATION
Agency Listings ............................................................................................................................... 9
SPECIFICATIONS .......................................................................................................................... 10
WARRANTY INFORMATION ....................................................................................................11
TABLE OF CONTENTS
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!WARNING!
Risk of Electrical Shock. Disconnect or isolate all power supplies before making electrical
connections. More than one disconnection or isolation may be required to completely
de-energize equipment. Contact with components carrying hazardous voltage can cause
electric shock and may result in severe personal injury or death.
!IMPORTANT!
All wiring must conform to local, national, and regional regulations. Use copper conductors only
for all wire connections. Do not exceed the electrical ratings for the WF-8950L2-MBA or the
equipment connected to it.
!CAUTION!
is product should be installed by an experienced technician. CAUTION and care must be
taken when servicing this equipment. To prevent severe shock or electrocution, consult your
servicing dealer.
!WARNING!
is unit employs components that can produce arcs or sparks. To prevent re or explosion, do
not install in compartments containing batteries or ammable materials (LP gas). is product
is NOT ignition protected.
!CAUTION!
To prevent re, do not cover or obstruct front cover ventilation openings. For continued
protection against risk of re or electric shock, replace faulty DC fuses with ones of the same
type and ratings as are installed.
!WARNING!
Use converter only on appropriate battery systems. Other usage may cause personal injury and
damage. Consult all battery manufacturers’ recommendations for additional safety information
before use.
GENERAL INFORMATION
WF-8950L2-MBA Converter-Charger Safety Features
Reverse Battery Protection
e WF-8950L2-MBA will charge the 12-volt house battery if installed. A battery does not have
to be installed for the WF-8950L2-MBA to operate. When a battery is installed, two reverse
polarity fuses protect the MBA circuitry. e fuses are located on the le-center edge of the
DC fuse board below the VCC+ lug (refer to Figure 1 on the next page). is feature prevents
permanent damage to the MBA from a battery connected into the circuit backwards. In addition
to protecting the MBA, the reverse polarity fuses are the main connection between the
WF-8950L2-MBA and the DC fuse board.

Automatic Cooling Fan
e cooling fan in the WF-8950L2-MBA is incremental and is controlled by the current
drawn out of the converter to the applied load. e on-board microprocessor increases
fan speed as the total load increases, and decreases fan speed as the load decreases. Unlike
traditional temperature-controlled fans, the load-controlled fan provides better component
cooling by avoiding temperature spikes which can lead to premature component failure.
Over-Temperature Protection
If the internal temperature of the converter exceeds a critical point, it will shut down. is
protects the unit from excessive heat that may damage sensitive components. e unit will
restart once the temperature inside has dropped.
Electronic Current Limiting
In the event that the output current exceeds the maximum rating for the WF-8950L2-
MBA, the output current will remain constant, but the output voltage will begin to drop. If
this occurs, the unit will recover once loads are reduced.
Short-Circuit Protection
Should a short circuit occur in the RV, the WF-8950L2-MBA will drop the voltage output
to zero volts. If the short-circuit condition is removed and no other fault conditions are
detected, the converter will resume normal operation. However, short-circuit conditions
are dangerous, and an RV will require inspection by a qualied service technician.
4
Figure 1

5
CIRCUIT PROTECTION
WF-8950L2-MBA Converter-Charger Fuses
DC Fuses (12 Volts)
e DC fuse board in the WF-8900PEC panel section includes all fuse receptacles for the DC
circuits and the Reverse Battery Protection circuits. e Reverse Battery Protection circuit has
space for 2 (two) 40 Amp fuses. e manufacturer of your RV has installed fuses for each DC
circuit that is operational. Any blown fuse will illuminate a red LED on the board next to the
blown fuse. Replace blown fuses with fuses of the same rating (printed on each fuse). Use only
ATC or ATO automotive type fuses such as:
• Littelfuse type 257
• Bussmann type ATC
OPERATIONAL FEATURES
Converter Operation Modes
Two-Stage Smart Charging
e two-stage “smart” charger continuously measures the battery voltage output and regulates
the amount of charge using two modes of operation; Bulk, and Absorption modes.
Converter Modes of Operation
Understanding output voltages of a two-stage converter.
Figure 2

6
Bulk Mode
is mode is designed with 2 purposes in mind. First, to quickly restore the energy back
into the battery. Second, to ensure the lithium cells inside the battery remain balanced. is
is accomplished by boosting the output voltage to 14.6VDC and allowing the maximum
current to ow as required by the loads.
e bulk mode stage could last anywhere from 1 to 4 hours based on the battery and load
current which is being used. For a full battery, the bulk stage has a minimum time
requirement of 1 hour, which allows the lithium cells inside the battery the time required to
“balance”. For an empty battery, the bulk stage has a maximum time requirement of 4 hours.
If your application requires longer than 4 hours (such as a larger battery bank > 200 Ahr), a
simple cycling of power will reset the timers.
As the energy is restored into the battery, the DC system voltage will climb and the current
from the converter will decrease. If the total amperage draw from the converter reaches a
preset point (within the 1-4 hour timer), the converter is designed to drop out of bulk mode.
Absorption Mode
is mode is designed with 1 purpose in mind. is purpose is to provide a safe operating
voltage for all loads in the RV. is is accomplished by reducing (from bulk mode) the
output voltage to 13.6VDC and remaining at this voltage until the power is cycled to the
converter.
e absorption mode stage is the default or normal mode of operation, which has no timer
associated with it. In this mode an output of 13.6 VDC is provided to the DC circuits in the
RV. is voltage has a long term history as the acceptable voltage for all loads in the RV, and
should not place undue stress (nor reduce the longevity) of the lights and appliances in the
RV. is is not to say that all loads will have an issue with a constant higher voltage;
however, some loads may have an issue. Please refer to the individual manufacturers
specications for acceptable operating voltage range of the connected load.
TROUBLESHOOTING INSTRUCTIONS
Troubleshooting the WF-8950L2-MBA Converter-Charger
Refer to the Troubleshooting Guide for the WF-8950L2-MBA (Figure 3) on the next page.
Converter Output Voltage
Before checking the WF-8950L2-MBA output voltage, disconnect the battery cables at
the battery. Make sure the converter is plugged into an AC source (105-130 Volts). Check
the converter output voltage at the battery with a voltmeter. Place the meter probes on
the disconnected battery cables; place the Positive (red) meter probe on the + Positive red
battery wire and place the Negative (black) meter probe on the - Negative black wire on
the battery cable. Be sure you have good connections at the cables. If the voltage reads 13.6
- 14.6 VDC (+/- 0.2) with no load, the converter is functioning properly.

If the above checks have been made but the converter output still reads 0.0 VDC, the
converter is not functioning properly. Contact the Arterra Distribution Power PROs at
1 [phone].
Figure 3
Should it be determined that the WF-8950L2-MBA needs to be replaced, removal of the
Main Board Assembly is a simple process.
INSTALLATION INSTRUCTIONS
Replacing the WF-8950L2-MBA Converter-Charger
Make sure no AC power is coming into the RV from either the Shore Power cord or an
on-board generator. Remove and set aside the Reverse Polarity Fuses located on the fuse
board to disconnect the converter section from the rest of the RV’s DC power.
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Perform the following steps:
1. Remove the door assembly by loosening the two screws located in the upper le and
right corners. e screws are captive and will not fall out. Pull forward and outward on
the door assembly to clear the case.
2. In the upper le portion of the fuse board, loosen the NEG- lug (White wire) and the
VCC+ lug (Red wire). Do not back the lug screws all the way out.
3. Locate the tab at the bottom of the fuse board holding the board in place. Gently
depress the tab allowing the fuse board to be pulled forward.
4. With the fuse board pulled slightly away from its mounting, pull the Red and White
wires out of the lugs.
5. In the AC section of the enclosure, locate the Black wire coming up from the converter
in the lower section. As an extra precaution, MAKE SURE THE CONVERTER
BREAKER IS IN THE OFF POSITION. Remove the wire from the breaker. NOTE:
this wire has a metal pin terminal on the end inserted into the breaker. Remove and
position out of the way any wire connected to the pigtail.
6. Locate and remove the converter’s Green Ground wire attached to the AC Ground bar
on the le side of the compartment. In a similar fashion, locate and remove the
converter’s White Neutral wire attached to the AC Neutral bar at the top of the
compartment.
7. In the converter compartment, remove the two screws at the front of the MBA holding
it in place. Slide the MBA forward routing the wires through the slots in the case until
the MBA clears the enclosure.
If the MBA is being returned under a warranty claim, follow the packaging instructions in
your warranty claim packet.
When installing a replacement MBA, reverse the order of steps 1-7.
Figure 4

GENERAL COMPLIANCE INFORMATION
Agency Listings
UL
e WF-8950L2-MBA is UL-Listed, and cUL-Listed (Canadian).
FCC Compliance Class B
NOTE: is equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. ese limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a
commercial environment. is equipment generates, uses, and can radiate radio frequency
energy, and if not installed and used in accordance with the instruction manual, may
cause harmful interference to radio communications. Operation of this equipment in
a residential area is likely to cause harmful interference in which case the user will be
required to correct the interference at his own expense.
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Figure 5