4
ELECTRONIC CURRENT LIMITING
In the event that the output current exceeds the maximum rating for the WF-8900-AD Series
Power Center converter, 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-8900-AD Series Power Center converter 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 c
onditions are
dangerous
, and an RV will require inspection by a qualified service technician.
CIRCUIT PROTECTION
WF-8900-AD-MBA Series Main Board Assembly Fuses and Breakers
REVERSE BATTERY PROTECTION
The WF-8900-AD-MBA Series Main Board Assembly will charge the 12-volt House battery if
installed. A battery DOES NOT have to be installed for WF-8900-AD-MBA Series Main Board
Assembly to operate. When a battery is installed, two reverse polarity fuses protect the MBA
circuitry. The fuses are located along the left-center edge of the DC fuse board below the VCC+
lug. Refer to Figure 1 below. This 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 MBA and the DC fuse board.
The fuse values and quantity vary depending on which WF-8900-AD-MBA Series Main Board
Assembly you have. Refer to the table below.
• WF-8935-AD-MBA – 35A (1)
• WF-8945-AD-MBA – 30A (2)
• WF-8955-AD-MBA – 40A (2)
• WF-8965-AD-MBA – 20A (4)
• WF-8975-AD-MBA – 20A (4)
The circuit fuses and the Reverse Battery Protection fuses should be replaced with ATC or ATO
automotive type fuses such as:
• Littelfuse type 257
• Bussmann type ATC
