An air conditioner fuse prevents any parts of heating, ventilating and air conditioning, or HVAC, to overload or overheat. It is a safety gadget that instructs the HVAC unit on how many amps to draw.
The fuse is designed to handle a specified amperage. If any part of the conditioner draws more amps than expected, the fuse turns off, breaking current flow. This is to protect the condenser from blowing. Placed within the fuse holder, usually the fuse box is in line of vision and within reach from the condenser unit position. Typically, the HVAC unit fuse is a heavy-duty, time-delay cartridge fuse.
When the outside A/C is not doing anything, it may be an indication that the fuse has blown. Using a voltmeter is the best way to confirm this. This involves taking voltage readings, which must be done carefully. First of all, one is required to locate the disconnect box, which is usually mounted near the outdoor condenser.
This is followed by exposing the wiring in the disconnect box. With the exposed wires, it is possible for one to see both incoming and the outgoing wiring. The wires are then placed on the respective terminals on the voltmeter and tested for voltage.