4 posts, read 42,523 times 3,632 posts, read 7,226,434 times Originally Posted by TrapperL Not true- A main disconnect on the exterior is required today, but that may have not been the case when OP's house was built. It's not a "sub-panel" it would be the main breaker/fuse panel. If you have a breaker/fuse in the main panel, why would you ALSO have breakers/fuses outside- Wrong! If there are breakers/fuses in the main panel, there are "disconnects" at the unit. If there are NO breakers/fuses in the main panel they will be at the unit(s). 804 posts, read 2,720,065 times Typical MAIN panel box as per requirements of the second largest electrical supplier in the Southwest. Inside the MAIN panel box. Note breakers for 220V only in this box which are the range/stove, A/C compressor in this case, and to the subpanel box. Typical SUB panel box as accepted by the second largest electrical supplier in Texas. This one is in the garage which is fairly typical for new construction.

Note double breaker on lower left of box. Typical air handler installation. All residential air handlers are 110V, just like this one. Note 110v duplex receptacle for power. In the case of this house, there is no breaker at the compressor as the unit is within 5ft of the main panel box. Otherwise, a correct breaker of the correct size is required by code in a box no farther than 5 ft from the compressor. You may substitute a breaker cutoff which is a handle affair that all you have top do is pull it and the handle comes out cutting off the electricity. They are a one time use part and the entire unit replaced if you pull it. Breakers are reusable and in the case of these units, provide additional backup and convenience of being able to turn the unit off and on without cost. 333 posts, read 891,606 times Originally Posted by QIS Furnaces generally don't plug into a wall receptcale.The air conditioner is outside the home and the furnace is inside. To diagnose heating, ventilation and air conditioning problems, start with the easy, visible items and work your way to the hidden components.

An HVAC consists of a furnace, an air conditioner, ductwork and a fan connected to the ductwork. The thermostat controls these elements by signaling them to turn on or off based on programmed settings. car ac repair how muchAs part of the ventilation system, a filter sits inside the cold air return that removes contaminants from the air before heated or cooled air is distributed throughout the home. how much electricity does an ac window unit useDiagnosis Begin your diagnosis of the HVAC system by verifying that it has power. window ac units with thermostatLocate the service panel and ensure the circuit breaker has not tripped. The furnace and the air-conditioner each have their own dedicated circuit breaker or fuse. Turn the circuit breaker off for the unit that is malfunctioning.

Wait about 10 seconds and switch it back on. If you have fuses instead of circuit breakers, switch the main power off. Remove and replace blown, burnt or broken fuses. Next check the thermostat for power. Some thermostats receive power via the electrical system, while others contain batteries. Remove and replace batteries for battery-powered thermostats if there is no power at the unit. Furnace Switch the thermostat to "heat" mode and set the thermostat 3 to 5 degrees above the room temperature. Wait at least 30 seconds before checking for heat at an open register. If no heat comes out, turn the thermostat off. Confirm that the panel door on the furnace is closed. A switch inside the panel door allows the system to operate when it is fully engaged. If not engaged, the heater won't come on. Reset the furnace by opening the panel door and turning off the gas or pushing the reset button. Wait five minutes -- or follow the instructions in the unit's manual for reset -- then turn the gas back on.

Air Conditioner Set the thermostat to "cool" mode. Adjust the thermostat setting 3 to 5 degrees below the room temperature. Locate an open register and check for cool air after waiting for 30 seconds. Reset the air conditioner at the circuit breaker. If the air conditioner was running, but stopped producing cold air, check the air conditioner for water below the unit. If there is water, dirty coils can cause the coils to freeze. Turn the air conditioner off at the thermostat and circuit breaker, let the unit sit for three hours, then clean the coils and restart the unit. Ventilation Ensure the fan is on at the thermostat and the registers are open. Newer thermostats have two settings for the fan: "on" and "auto." When set to "on" the fan will run continually. When set to "auto" the fan kicks on with the heater or air conditioner calls for it. Locate the cold air return and remove the filter. Examine the filter for dirt. Cold air return filters must be clean for the system to operate efficiently.

If your filter is a permanent one that requires cleaning, follow the steps in the owner's manual. Locate the arrow on one side of the filter that shows the direction the air flows. After cleaning, ensure that you put the filter back with the arrow pointing toward the ductwork inside. Replace the disposable filter with a new one. If the registers for the ventilation system do not deliver air, locate the blower motor and check the belt for cracks or breaks. References Hannabery HVAC: Heating Troubleshooting ChecklistTrane: Troubleshooting Photo Credits Jupiterimages/Comstock/Getty Images Suggest a CorrectionElectrical System DesignMost RV’s and camper trailers utilize the same types of electrical systems as those used for an average small home. But in addition to the 110 volt electrical supply, there may also be lights, fans, a refrigerator, or other electrical devices which use a 12 volt supply, like that of a car or truck. A 12-volt DC system powers the RV refrigerator to keep food cold while the RV or camper trailer is moving from place to place.

The same goes for the lights and fans. It also keeps the on-board batteries fully charged. This system relies on the 110-volt AC electrical power supply for amperage. It is possible to pull a 12-volt power supply from the RV or camper trailer's electrical system or 110-volt campsite power supply. Then the 110-volt supply can be stepped down to 12 volts after it is run through a power converter and to a particular appliance. Most of RV systems will switch from the 110-volt AC to the 12 volt DC supply automatically when there is a power interruption. These two electrical systems are treated independently from each other when diagnosing electrical problems, except for determining power to the converter. 110 volt power-- > converter-- > 12 volt power-- > 12 volt breaker box -- > refrigerator or lights As in a home, the 12-volt system has its own set of breakers to control each circuit. The lights, fans, or refrigerator may each be on their own circuits, depending on the amperage required.

If the converter is supplying 12 volts to the breaker panel and the breakers test positive for voltage, this leaves the wiring or the particular appliance at fault. Essential Tools and ResourcesIf you are not familiar with electrical wiring or troubleshooting electrical systems there are some very good books available to help you understand and repair common RV electrical problems. I would recommend RV Electrical Systems: A Basic Guide to Troubleshooting, Repairing and Improvement to any novice and experienced electrician alike. It will be an enormous aid to understanding RV electrical systems. Another must for tracing down electrical problems is a voltage meter. This handy tool will allow you to check the circuits for continuity and for the correct voltage required for each breaker. A simple test light can be used but will not test for broken circuits caused by bad wiring or other electrical problems. Both of these tools are inexpensive to own and will more than pay for themselves over time.

The voltage meter can be used for home electrical problems as well as any other electrical related problem. Both are offered on this page for a reasonable price. Troubleshooting Common 110-Volt ProblemsThe 110 volt outlets used in some RVs and camper trailers are prone to shorts because of the way they are installed. Some are merely clipped onto the wiring by cutting into the wires. These types are notorious for not working correctly. Replace these types of outlets with standard house types to put and end to loose connections. Since some of the walls are so thin, a smaller receptacle box may be required for the outlet to fit flush in the walls. Ground fault interrupter outlets are another common cause of electrical problems. These are located in places where a possibility exists of someone touching them with wet hands. They automatically break the circuit when moisture comes in contact with the outlet to prevent shock to the person touching them. A simple reset button must be pressed for the circuit to once again be completed.

On occasion they will need to be replaced or the other outlets on the line will not work either. Pay close attention to the instructions when replacing these GFIs. In older RVs and camper trailers you may still find fuses instead of circuit breakers. Since the advent of many new electrical devices, these older fuse systems may not provide enough amperage to handle a microwave or other high amp appliance without blowing a fuse or kicking a breaker. Simply replacing the fuse or breaker with a higher amp substitute may be all that’s required. Replacement of the entire breaker box may be the only option remaining if this doesn’t solve the problem. The newer RVs and camper trailers may have two RV A/C rooftop units which require more amperage than the older models to operate without kicking the standard 30-amp power supply used by many campgrounds. Fortunately, many campgrounds and RV parks now provide 50-amp service for these types of units. When making reservations or checking in, be sure to ask about the availability of a 50-amp hook-up if you own a unit with multiple A/C units.