20T medium frequency steel shell induction melting furnace technical specification and complete set range
I Technical program and specification
This program is recommended that whole set equipment of the furnace shall be equipped with two furnace bodies user can be readjusted by practical needs.
1.1 Technical program
The main equipment of this program is included 2 5000KVA rectification transformer, 4 low voltage control cabinet, 4 9000KW/250Hz MF power supply cabinet, 2 20t MF induction furnace, 1 hydraulic station, 1 cooling water device, and other auxiliary device. The electric system diagram is as follows:
Secondary voltage  V  950  
II Products standard and Operating conditions
2.1 Products standard:
GB10067.3-1988 'Basic specifications for electroheat installations--Induction electroheat installations'
GB10067.1-1988 'Basic specifications for electroheat installations_General'
GB10066.3-2004 'Test methods for electroheat installations--Coreless induction furnaces'
GB5959.1-2005 'Safety in electroheat installations-- General requirements'
GB5959.3-1988 'Safety in electroheat installations--Particular requirements for induction and conduction heating installations and induction melting installations'
GB/T4280-2004 'Coreless induction furnaces'
GB/T8669-1997 'semiconductor frequency conversion devices for intermediate frequency induction heating'
GB5226.1-2002 'Safety of machinery Electrical equipment of machines General requirements'
2.2 Operating conditions
2.2.1 Cooling water conditions
pH: 7-8.5
Hardness: <10 degrees(Each degree that 1L water contains less than 10mg calcium oxide)
Total solid content: <250mg/L
Water resistance: (Power)>100KΩ -cm
(Furnace)>2KΩ -cm

2.2.2 Power supply conditions
Three-phase voltage unbalancedness <5%
B Voltage fluctuations <± 5%
C. Voltage waveform distortion factor <10%

2.2.3 Geographical environment
A. Altitude above sea level <1000m
Temperature 5~40c
Relative humidity <90%(>20c)
No electric and incentive atomy, no Explosive Gas and no caustic gas
Avoid strong shake and concussion.
III Electrical Technique Instruction
Electrical parts of the equipment include rectification transformer, low-voltage switch cabinet, intermediate frequency power cabinet, flat wave reactor, and compensation capacitor bank and water tank.
3.1 Rectifying transformer
This equipment uses special-purpose rectification transformer, which transforms 35KV or the 10KV high voltage of the electrical network to 950V, which is suitable for the solid power.
There is a no-load manual changer at the high voltage side of transformer, output voltage can be adjusted at-5%, 0, +5%. It is used tosuit the deviation of grid. In order to ensure the safety of silicon-controlled rectifier and avoid impact on the grid, this transformer request the big short circuit resistance value 10%, simultaneously adds the shielding layer between the original and vice-coils. There are a gas relay and the oil thermometer on the power transformer, its output is chain-reacted with high-voltage switch cabinet, when there appears the gas alarm or higer oil temperature, it will automaticlly turn off the power.
Cooling of the Transformer uses the oil bath self-cooling.

3.2 Low-voltage switch cabinet
The low Voltage switch - automatic air circuit breaker (DW15) is installed between the transformer output and the intermediate frequency power input, it is used in the make-and-break and isolates the overhaul of intermediate frequency power source.
The air circuit breaker has fast broken load protection and the no voltage release protection