What certificate does the enterprise need for intermediate frequency furnace smelting?

Enterprise intermediate frequency furnace smelting needs safety license. According to relevant data, intermediate frequency furnace is a kind of equipment used for casting, forging and hot working, which consists of frequency conversion device, furnace body and furnace front control. Intermediate frequency furnace needs to convert three-phase power frequency alternating current into direct current, and then convert it into single intermediate frequency alternating current through inverter circuit, so as to apply for safety license.