Infineon Original Infineon 6RA70 DC Speed Governor /SCR Module TT162N14KOF

Infineon TT162N14KOF | TT-Series Dual SCR Power Module — 1400V / 162A, SCR Doubler with Auxiliary Cathode

Part Number: TT162N14KOF

Manufacturer: Infineon Technologies (Germany)

Product Type: PMOD — Dual SCR (Thyristor) Power Module

Product Series: TT Series (Infineon Power Modules, TT Family) 

Two Thyristors, One Package

The TT162N14KOF is from Infineon's TT series — a product family that integrates two SCR (silicon controlled rectifier / thyristor) devices in a single power module housing. The "doubler" circuit configuration arranges the two SCRs in an anti-parallel relationship with a shared auxiliary cathode terminal. This configuration is the standard building block for single-phase or three-phase controlled rectifier bridges — two TT-series modules (or appropriate combinations with diodes) form the bridge configurations used in DC motor drives, battery chargers, and process power supplies.

At 1400V blocking voltage and 162A average current, the TT162N14KOF targets medium-to-large industrial applications. The 260A RMS current rating accommodates the higher instantaneous current that occurs during the partial conduction cycles of phase-angle-controlled rectification, where the SCR conducts for only a portion of each AC half-cycle. The gap between the average (162A) and RMS (260A) ratings is a direct consequence of the non-sinusoidal current waveform in controlled rectifier operation.

Applications and Drive Usage

Dual SCR modules like the TT162N14KOF are standard components in:

• DC drive converter input stages (SIMOREG 6RA70 and similar)
• Phase-angle-controlled power supplies
• Soft starters using thyristor switching
• UPS rectifier stages
• Industrial heating and electrochemical process power supplies

In DC drive applications, the TT162N14KOF's 1400V rating provides adequate reverse blocking margin for supplies derived from 480V–690V AC three-phase systems, where the peak inverse voltage across the SCR reaches approximately 1.4× the line voltage during commutation.

Key Specifications

FAQ

Q1: The DC drive shows asymmetric armature current or a firing fault on one phase. The TT162N14KOF is suspected. How is the module tested?

With the module de-energised and gate leads disconnected, use a multimeter to measure forward and reverse resistance between the anode and cathode of each SCR. A healthy SCR shows high resistance in both directions (megaohm range or OL). A short circuit in the forward or reverse direction indicates a failed SCR. Gate-to-cathode resistance should be in the low hundreds of ohms range for both devices.

Q2: What is the practical significance of the auxiliary cathode terminal in the SCR doubler configuration?

The auxiliary cathode provides a low-current, low-inductance gate reference terminal separate from the main cathode that carries full load current. Gate drive circuits connected to the auxiliary cathode are not affected by the voltage drops in the main current path, which improves firing reliability and simplifies gate drive circuit design — particularly at high current levels where main cathode lead resistance and inductance would otherwise affect the gate trigger threshold.

Q3: The TT162N14KOF replacement was installed but the SCR is firing intermittently. The gate drive circuit was not changed. What should be checked?

Intermittent firing with an unchanged gate drive circuit is typically caused by insufficient gate trigger current for the new module's triggering requirements. SCR trigger threshold (IGT) can vary between units even within the same product series. Measure the gate current delivered by the existing gate drive and compare against the TT162N14KOF's specified minimum IGT. If the gate current is borderline, the drive circuit may need adjustment.

Q4: Can the TT162N14KOF be operated at its full 162A average current rating continuously?

Continuous operation at the rated average current requires the module's case temperature to be maintained at or below the temperature assumed for the 162A rating (typically 40°C case temperature). This requires an adequate heatsink with appropriate thermal resistance and adequate cooling airflow. At elevated case temperatures, the permissible average current decreases according to the derating curve. Always verify the thermal design under actual operating conditions before commissioning at rated current.

Q5: Is the TT162N14KOF interchangeable with other TT-series modules of the same current and voltage rating?

Within Infineon's TT series, modules with the same voltage (14 = 1400V) and current (162N = 162A) from different production periods or with different suffix characters may have minor differences in mounting footprint or terminal layout. Confirm the package dimensions and terminal positions match the existing installation before fitting a replacement. The TT162N14KOF "OF" suffix identifies specific package and terminal options — confirm the suffix matches if sourcing from alternative suppliers.