Product Details:

The RELIANCE 0-49009-1 transductor board is an essential drive spare part designed for legacy RELIANCE CardPak DC drive rack control systems. This current sensing card uses magnetic transductor components to isolate and sample the AC current signal from the thyristor power circuit, then converts the sampled signal into a proportional low-level analog feedback signal for the main regulator card. The regulator relies on this accurate current feedback signal to implement current loop regulation, torque limiting and overcurrent protection functions. It forms the core current closed-loop channel of the CardPak drive system. If the transductor board suffers magnetic core saturation, component drift or signal loss, the drive will show current feedback deviation, torque control failure, false overcurrent alarms and sudden drive shutdown.

This current sensing card adopts standard plug-in slot structure and can be directly inserted into the dedicated RELIANCE CardPak drive chassis. It communicates with regulator cards, limit protection boards, ramp timing boards and auxiliary power boards through the internal backplane bus. The transductor structure provides high electrical isolation between the high-power main circuit and low-voltage control circuit, which can effectively block high voltage surge and common-mode interference. Adjustable trim resistors on the PCB are reserved for technicians to calibrate gain and offset to match the rated current of the power stack. Multiple filter circuits suppress switching noise generated by thyristor commutation and stabilize the output analog signal. The board is powered by 24V DC auxiliary control power supply, with a net weight around 0.52kg. Its rated working ambient temperature range is 0℃ to 55℃, and storage temperature ranges from -20℃ to 70℃. LED indicators display signal output status for maintenance staff to quickly judge whether the current sensing loop works normally.

This RELIANCE 0-49009-1 current sensing card is widely used as maintenance spare parts for traditional DC speed regulation equipment in metallurgy rolling production lines, paper making machines, cable extrusion lines and other heavy-duty industrial equipment that requires precise current closed-loop control. The original manufacturer has discontinued this transductor board, and most units available on the global industrial spare parts market are fully tested refurbished units. Before installation, technicians need to inspect the magnetic transductor core, precision resistors, filter capacitors, PCB traces, solder joints and gold fingers for aging, insulation damage or poor contact. After rack installation, users need to check the primary wiring polarity, complete current feedback calibration, and carry out no-load and load current verification tests. Careful inspection and calibration of this transductor board can avoid torque instability and false overcurrent trips, reducing unplanned production downtime.