In electrical equipment the heat is generated through a heating element. Wiring inside the heater accepts incoming electrical power. It may be microchrome wire (round or flat ribbon wire), fiberglass coated or mica coated. Fiberglass can handle temperatures as high as 400 degrees Fahrenheit, and much more expensive mica coated wire can handle up to 1000 degrees Fahrenheit. The heating elements are also categorized with their watt density, or the number of watts they can produce per square inch. The higher the watt density, the greater the devices ability to provide uniform heating.
If a device does not have a light switch, it has a thermostat to control the heat. A thermostat also turns on and off the equipment so that it can heat to the desired temperature and then turn on and off to keep that temperature as long as needed. The bike is often controlled by magnetic force. The thermostat magnets act as contacts and keep the power connected until the correct temperature is reached. then a bimetallic control causes the magnets to open.
This releases the energy connection and the heat stops - until it cools down enough to cool the bimetal, causing the magnets to snap and complete the energy run and the cycle begins again. Solid State Controls - which use microprocessors to turn on and off switches instead of moving parts or heated filaments - are now available in many types of kitchen equipment.
Kitchen appliances should also be equipped with their own twists, which can be easily disconnected for cleaning and service. Neoprene ribbon is popular, as neoprene is a tough but flexible substance that can withstand both water and fat. Nevertheless, neoprene will soften under extreme heat conditions. Rubber coated wires are not suggested, simply because they soften and deteriorate under fat and heat.
Nowadays, many heavy commercial cooking appliances can be ordered (at extra charge) for direct connection to a 460-volt system. Nevertheless, 460 volt equipment does not contain internal fuses or power switches to isolate problems. An error in any component from the switch will cause the entire case to shut down completely until the problem is placed and repaired. When new equipment comes into your kitchen, the nameplate often reads a lot more time before you connect it.
If you do not follow the electrical requirements, you will notice problems. If the operating voltage is lower than it will be, the heat will heat more slowly or not completely heat, no matter how long it remains. For example, a 12-kilowatt fryer will be connected to a 208V power supply, to be 25 percent less efficient and take longer to preheat. If the operating voltage is greater than recommended, the appliance will get warmer, heat faster and perhaps burn the elements much faster than it should.
The same 12-kilowatt freezer, when connected to a 240-volt outlet, heats faster, but it will shorten the devices service life, simply because all parts work harder than they were intended to work. Should you know some of the energy-related information for a particular device, but not all, remember that there are formulas that can be used to calculate what you need to know. If an appliance is rated in kilowatt hours (kW), you can convert this value to watt (W) and find out how many amps (I) it will require.
We are trying. Lets say we have a single-phase 13.2 kW device. It is rated at 208 volts, but we need to know how many power amplifiers are required. First we need to convert kilowatt to watts. This is really a standard calculation, as we know that 1 kilowatt corresponds to 1000 watts: 13.2 kW x 1000 = 13 200 watts. Then we use the formula we learned earlier to convert watts to amps: I = W: E.
For this device it means: Amps = Watt: Volt or Amps = 13,200: 208 = 63,5.
This device requires 63.5 amps of electricity. Electric Food Service Council has calculated the power requirements for several types of appliances: for example a gas lamp (a necessary
component of each cooking device approved by the American Gas Association) consumes approximately 750 Btu gas per hour. Multiply it with 24 hours a day, and its 18,000 Btu per day or 18 cubic feet.
(Gas is purchased in cubic feet.) If a cubic foot costs five cents, this corresponds to 90 cents a day. The kitchen containing a dozen gas appliances will spend almost 4000 dollars a year just to keep the pilot lights on.