MDD-250-12

Internal circuit and operating principle

The internal circuit contains Two series-connected silicon diodes in a half-bridge circuit. This arrangement is used as a power rectifier arm and provides a compact insulated assembly for AC-to-DC conversion. For background on the semiconductor principle, see diode. The published operating-frequency limit is Up to 500 Hz / до 500 Гц, and the external circuit must follow the terminal diagram marked on the case or specified in the product passport.

MDD-250-12 electrical ratings

The principal catalogue ratings are 250 A average current and 1200 V repetitive voltage. The listed surge-current capability is 11 kA; the maximum forward-voltage value is ≤ 1.25 V. The maximum leakage-current value is ≤ 30 mA, while the junction-temperature range is −60 to +125 °C. These are selection limits, not permission to operate without thermal calculation and the applicable technical documentation.

Housing, cooling and installation

The module uses the MTD3 case and measures 115 × 50 × 61 mm with a mass of ≤ 800 g. Natural or forced-air cooling may be used with compatible heat sinks O26, O36, O46, O55, O56, O57, O58. The mounting surface must be flat and clean, and the terminal hardware must be tightened to the value stated in the passport. The published ambient range is −60 to +50 °C.

Identification and selection

Match the full MDD-250-12 marking, circuit symbol, terminal layout, voltage class, current rating and housing size. Similar MDD, MTT and MTOTO devices are not interchangeable merely because their case dimensions are alike. Confirm the cooling arrangement and technical conditions before installation. Related products are grouped in Electronic Modules.