IEC 60779-2020 pdf free download

IEC 60779-2020 pdf free download.Installations for electroheating and electromagnetic processing — Test methods for electroslag remelting furnaces
Installations pour traitement électrothermique et électromagnétique — Méth odes d’essai des fours de refusion sous laitier électroconducteur.
8.104.4 Measurement of currents of the coaxial return conductors
In the case of an electroslag remelting furnace of a coaxial design for a single phase AC supply, the secondary current shall be measured by separately measuring the current in each of the return conductors, respectively, and then summing the currents to derive the total current and deriving the current difference to determine coaxiality, as shown in Figure AA.3.
8.105 Measurement of the active power, reactive power and power factor of the electroheating installation
The test comprises measurement, at the input terminals of the power supply (see item 4 in Figure AA.1), of the power of an electroheating installation (defined in 3.1.102) and the power factor of an electroheating installation (defined in 3.1.103).
The measurement of the active power is made by means of a wattmeter (at least of class 1 .5). The measurement of the reactive power is made by a varmeter (at least of class 1.5).
NOTE If a suitable varmeter is not available, the reactive power can be calculated from the measured values of current and voltage.
The measurement shall be carried out during continuous operation of the furnace after steady state has been achieved.
The power factor is calculated from the active and reactive powers measured as mentioned above or, when the measurement of the reactive power has not been made, from the active power value and the value of the apparent power calculated from the measured voltage and current values.
Attention should be paid to the fact that harmonics might affect the results of measurements.
8.106 Measurement of the melting rate of consumable electrode(s)
The measurement shall be carried out with the load cells during continuous operation of the furnace if the furnace is equipped with a load-cell system. The test conditions and procedure shall be agreed upon between the manufacturer and the user.
For a furnace without a load-cell system, it may be replaced by tests which prove that, in normal operating conditions of the furnace, the melting rate of consumable electrode(s) remains in the range stated by the manufacturer.
8.107 Measurement of vacuum parameters for a vacuum electroslag remelting
furnace
8.107.1 Measurement of the limit vacuum pressure
The test is made in the cold state with vacuum instruments installed in the vacuum system of a
furnace. The vacuum pumps are switched on until the pressure in the furnace reaches a
minimum value. The vacuum pressure should remain in the range stated by the manufacturer.
8.107.2 Measurement of the pumping time
The pumping time is the time interval during which the vacuum pressure decreases from the atmospheric pressure to the limit value after the vacuum pumps are switched on in the above test (see 8.107.1).
8.1 07.3 Measurement of pressure rise rate
The test shall be performed after all the vacuum valves in the vacuum chamber are closed and the pumps are switched off when the above test is finished (see 8.107.1). IEC 60779-2020 pdf free download.