The parallel inverter power supply is the usual converter for a coreless melting furnace. It starts across a wide load range and keeps a stable current limit when scrap bridges or the bath condition changes.
Technical Data
| Input voltage (V) | Rectifier | Medium-frequency output (V) | Furnace body voltage (V) | Output power (kW) | Furnace capacity (t) | Output frequency (Hz) |
|---|---|---|---|---|---|---|
| 380 | 6 or 12 pulse | 750 | 750/1500 | 20–1000 | 0.01–3 | 150–1000 |
| 660 | 6 or 12 pulse | 1200 | 2400 | 500–3000 | 1–8 | 500–1000 |
| 660 | 6 or 12 pulse | — | — | 2000–4000 | 2–10 | 500–1000 |
| 1000 | 12 or 24 pulse | 1600 | 3200 | 4000–8000 | 5–12 | 250–500 |
| 1000 | 24 pulse | — | — | 8000–20000 | 12–40 | 150–250 |
| Item | Catalog statement |
|---|---|
| Start | Automatic frequency-sweep start |
| Rectifier control | Large-scale phase-shift trigger, strong anti-interference |
| Current limit | Holds under load change so a bridge does not trip the supply |
| Protection | Short circuit, open circuit, phase loss, low water, water shortage, over-current, over-voltage, phase stagger |
| Fault stop | Automatic safe stop |
| Rectifier pulse | 12 pulse and 24 pulse to cut grid harmonics |
| Melt under 1 t | One furnace in 20 to 50 minutes |
| Power saving stated on the sheet | 10–20% against a traditional medium-frequency furnace |
| Rectifier | 5th | 7th | 11th | 13th | 17th | 19th | 23rd | 25th |
|---|---|---|---|---|---|---|---|---|
| 6 pulse | 0.175 | 0.11 | 0.045 | 0.029 | 0.015 | 0.01 | 0.009 | 0.008 |
| 12 pulse | — | — | 0.007 | 0.004 | 0.002 | 0.001 | 0.0009 | 0.0008 |
| 24 pulse | — | — | — | — | — | — | 0.0006 | 0.0005 |
| US standard | Applies to |
|---|---|
| IEEE 519 | Harmonic current limits, matched to 6 / 12 / 24 pulse rectifiers |
| NFPA 70 (NEC) | Incoming voltage, grounding and disconnect |
| UL 508A | Control cabinet construction |
| NEMA 250 | Enclosure type for the power cabinets |
| NEMA MG 1 | Cooling-fan and pump motors |
Every figure in these tables is taken from the factory sheets in the product folder and is written in English. 1 metric ton = 1.102 US short tons. Power-supply ratings can still be negotiated to the customer requirement, as the sheet itself states. American standards are the US specifications normally requested with this equipment.
Key features
- Automatic frequency sweep start
- Strong current limiting during pull-out and bridging
- Simple commissioning compared with a series inverter
- Full protection set, including automatic stop on a furnace fault
Construction
- Rectifier, DC reactor, parallel inverter and capacitor bank mounted with the furnace coil.
Working principle
The furnace coil and the capacitor bank form the resonant tank. The inverter switches in step with that tank and delivers power into the melt.
Applications
Steel, cast iron, stainless steel, copper, aluminum, aluminum alloy, brass and other non-ferrous metals.
Complete system integration
This equipment sits in the same line as the power supply, the capacitor bank, the induction coil, the magnetic yoke, the furnace body and the cooling system. A quotation can cover one item or the full line.
Customization
Capacity, voltage, frequency, dimensions and connection layout can be made to the furnace design. Send the drawing or the duty data below.
Catalog sheets
Questions before a quotation
Can the rating be customized?
Yes. Capacity, voltage, frequency, tube size and connection layout follow the furnace drawing and the metal.
What do you need for a quotation?
Furnace capacity, metal, melting temperature, melting rate, working hours, input voltage, frequency if known, tilting method and cooling-water conditions. A drawing helps.
Do you supply a single machine or the complete system?
Both. A spare coil, yoke, capacitor or cooling tower can be quoted alone. A new foundry line is quoted as a complete system.
Which metals can be melted?
Steel, cast iron, stainless steel, copper, aluminum, aluminum alloy, brass and other non-ferrous metals. The lining and the frequency follow the alloy.
Will you confirm the catalog numbers before manufacture?
Yes. The sheets on this page are the factory catalog for selection. The quotation states the rating that will be built.