How to Repair an Electric Furnace

An electric furnace includes an heating element, comfort controls, forced-air distribution system and an electrical service panel to connect to the power and electricity sources. Electric furnace is a type of resistance furnace, in which heat is produced either by passing current through a resistance element encircling the furnace or by using the resistance of the material being heated. The heating element can be a metal wire coiled around a tube of refractory material or a tube of metal made of resistive material like carborundum. The electric furnace works at the highest temperature of 4100° C (7366° F), which is the temperature used to manufacture graphite.

The electric-arc furnace is a type of electric furnace, which is widely used for the production of quality alloy steel. In this, the heat is generated by an arc struck between the metal and one or more electrodes suspended above the metal. Usually, an arc furnace has three electrodes, fed by a three-phase power supply for imparting three heating arcs. The electrodes are formed either from graphite or carbon.

The induction furnace is the latest version of electric furnace comprising a crucible, in which a metallic charge is heated by eddy currents induced magnetically. The crucible is wounded with a coil that passes high frequency alternating currents through it. One of the biggest advantage of induction furnace is that, it melts the metal at a faster speed in comparison to other furnaces. In fact, the modern furnaces are designed to operate at frequencies of 1 million cycles or more per second.

Repairing an Electric Furnace
Sometimes, the electric furnace may not produce enough heat or may turn on and off repeatedly. The blower may run continuously and the furnace may be noisy. These are some of the problems that you can face while using an electric furnace. Hence, to repair an electric furnace the first step is to identify the problem and check the electrical service panel for a blown fuse or tripped breaker. Try resetting the unit by pressing the reset button as sometimes units have a built-in breaker or fuse panel. Raise the thermostat setting by five degrees to check if the unit is on. If it does not produce enough heat, check the comfort controls. Clean or exchange the dirty filter and blower assembly and keep in mind that all registers should be opened and not blocked. If the furnace is noisy, check the access panels to ascertain whether they are mounted and fastened properly. Spray the creaking belts with fan-belt dressing and replace the worn or damaged belts. Regulate the blower belt and lubricate the motor and blower oil ports. If the rooms are not getting heated uniformly, the distribution system may need balancing. For resetting the circuit breakers, damaged fuses or if the electrical service panel doesn't restore power to the furnace, call a HVAC technician.

It is estimated that electric furnaces generate nearly two-fifths of the steel made in the United States. They are employed to produce stainless steel, electrical steel, tool steel and some special alloys. Small furnaces are used in laboratories and shops for heating tools and large furnaces are used for melting brass.