KW = Weight of material (KG) x Specific Heat (Kcal/Kg °C) x Temperature rise (°C)
Wattage required to heat Liquid:
KW = Weight of Liquid (KG) x Specific Heat (Kcal/Kg °C) x Temperature rise (°C)
Wattage required to Heat Air
For free flow air:
KW = CFM x Temperature Rise (°F)
Use the maximum anticipated airflow.
For compressed air:
KW = CFM* x Density*(lbs/cu. ft.) x Temperature rise (°F)
Note: Please add Heat Loss, Factor of Safety, and if any.
To convert Temperature in Centigrade to Fahrenheit
|Heat flow rate |
|Horse power |
|Pressure conversion |
Elmec Heaters & Controllers Terms & Conditions of Sale
Acceptance of order :
Cancellation charges depend upon the portion of the products completed at the time of such cancellation. The buyer shall pay the cancellation charges estimated by Elmec Heaters & Controllers.
Delivery dates are approximate and are based upon prompt receipt of all necessary information from purchaser (i.e. Purchase order, Advance payment, clarifications, samples, drawings, point of delivery etc…) FOB Chennai. Risk of loss shall pass to Buyers on delivery at the FOB Point. Elmec Heaters & Controllers shall prepay freight, and select the means of transportation unless buyers provide specific written instruction other wise with Buyer order. Elmec Heaters & Controllers shall not be responsible for delivery of any quantities for which Buyer has not given shipping instructions.
On complex heating of control systems an engineering charges may be applied to the first order only. Engineering charges may not be applied if similar items are ordered again. This charge is not subject to discount.
Elmec Heaters & Controllers Shall not be liable for delay in delivery or for failure to manufacture or supply of products in the event of: Act of God, war riot, fire, explosion, Accident, Flood, sabotage, Lack of adequate, power, fuel, labour, raw materials, transportation facilities, compliance with governmental requirements, breakage or failure of machines, testing instruments or any other events whether or not of the class or kind enumerated herein beyond the control of such party or in event of labour or trouble, strike, lockout. Which event makes impracticable the manufacture, transportation, sale, purchase, acceptance, use or resale of products or a material upon which the manufacture of product dependent.
If Elmec Heaters & Controllers determines that product or any materials used for manufacturing the products of any quantity directly or indirectly is hindered, Limited or made impracticable to manufacture obtain or purchase, Elmec Heaters & Controllers may allocate its available supply of products or such material (without obligation to acquire other supplies of any such products or materials) among itself and its purchase on such basis as Elmec Heaters & Controllers determines to be equitable without liability for any failure of performance, which may result there from.
|What it is ?||Any foreign material that is or becomes electrically conductive.||Anything that causes the temperature of the resistance wire in the heater or the lead wire to exceed its temperature rating.||Turning the heater on & off on a cycle that allows the resistance wire in the heater to cool of by several hundred degrees below the temperature reached when "on".|
|What it does?||Makes a conductive path between the resistance or lead wire and any "grounded" object (such as the heater sheath or metal lead protection) thus causing an electrical short.||If the insulation rating is very high such as a ceramic, as used in cartridge heaters , the resistance wire itself may oxidize or melt; otherwise, the insulation breaks down, allowing the resistance wire to short through.||Any temperature cycle, even one, shortens heater life because it causes more rapid oxidation on the surface of the resistance wire, then tends to break off the oxide coat when cooling. The greater the temperature difference in the cycle over time, the shorter the lifetime.|
|Typical causes ?||1 ) Water, when soaked into the insulation of either the lead wire or the element water makes a good short. Even high humidity can cause a problem. |
2 ) Oil,plastic or other hydrocarbons. These materials are insulators at room temperatures, but conductors at higher temperatures. It only requires trace amounts to cause a short.
|The basic cause of over - temperature is that the heat is not being removed from the heating element fast enough (for example wattage too high for application ). If the wattage of the heater was selected well for the application,then these factors are typically responsible |
1) Heater not in good contact with the surface of the object being heated.
2) Higher than design voltage applied to heater.
3 ) Heater not being used as directed (for example, strap not tight on band heaters, or reduced fuel flow rate on immersion heaters ).
4) Thermocouple used to monitor the temperature of the part being heated is not in good contact with the part.
|Wattage of the heater is much larger than needed and being used with a temperature controller that runs the heater on long enough for the element to get hot, then keeps it off long enough to become cool.|