Resistance & Diameter of heating element

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Discussion Overview

The discussion revolves around the design and specifications of a heating element, focusing on the discrepancies between theoretical and measured resistance values, as well as the connection of the heating element to a three-phase power supply. Participants explore the implications of different configurations and voltage levels.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant calculates the theoretical resistance of a heating element based on supply voltage and power, arriving at 5.4 Ohms, but notes a measured resistance of 17 Ohms using a multimeter, questioning the reasons for this discrepancy.
  • Another participant inquires about the connection of the heating element to three-phase power and raises a question regarding the standard voltage levels in the US, suggesting that 208V is more common than 220V.
  • A response clarifies that in KSA, a 220V three-phase supply is available and mentions that the heating elements are connected in a star (Y) configuration.
  • One participant explains that if the heating element is connected in a delta configuration, the resistance of each leg would be three times that of a Y element, calculating a resistance of 16 Ohms based on a 380V supply.

Areas of Agreement / Disagreement

Participants express differing views on the voltage supply and configurations of the heating element, with no consensus reached regarding the theoretical versus practical resistance values or the implications of different connection methods.

Contextual Notes

The discussion highlights potential limitations in assumptions regarding voltage levels and configurations, as well as the dependence on specific regional standards for electrical supply.

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Design of heating element:

Supply Voltage: 220V/3Ph/60HZ, Power: 9KW

Resistance= VXV/P= 220X220/9000= 5.4 Ohms, But when physically when measure the resistance of wire using multimeter it is showing 17 ohms. Can you explain why there is differnece in practical and theortical value.

Also, to find the diameter divide the found resistance by length and select the dia close to having resisitivity(R/L= Ohm/Meter) of above formula. But same as with this caluculation there is large deviation in values.

or can anyone provide a link to the literature find the resistance & dia of heater element.

Thanks in advance for help
 
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How is the heating element connected to three phase power?

And more, we usually have 208V three phase in the US, don't we? Where does the 220V come from?
 
Phrak said:
How is the heating element connected to three phase power?

And more, we usually have 208V three phase in the US, don't we? Where does the 220V come from?


The elements are connected in star or Y connection.

here KSA 220V/3PH is available.
 
I see. Apparenly the voltage of each leg of the Y is 220 VAC. So from each leg to another leg is 380 VAC.

If your heating element is connected in delta configuration, each leg of the delta should have three times the resistance of a Y element.

380*380/9000 = 16 Ohms.
 

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