The 30P4171B is a 30 HP non-regenerative DC drive belonging to Reliance Electric MaxPak Plus series. It operates with 460 VAC input and is engineered for separately excited DC motors. This one-quadrant drive is applied to unidirectional heavy-duty equipment. The original production has been discontinued, and refurbished units are widely used for maintenance and replacement of legacy industrial systems.

30 represents the rated power of 30 horsepower. P stands for MaxPak Plus series and non-regenerative type. 4 indicates 460 VAC input voltage class. 17 refers to the current rating matching 30 HP. 1B means hardware revision version B.

The three-phase input voltage is 460 VAC plus or minus 10 percent at 50/60 hertz. The rated power is 30 HP with continuous output current of 40 amperes. It supports 150 percent overload up to 60 amperes for one minute. The maximum DC bus voltage is 750 VDC. It adopts 6-pulse SCR control and works in one-quadrant non-regenerative mode. The speed regulation ratio reaches 50 to 1 when equipped with a tachogenerator. It accepts ±10 volt and 4 to 20 milliampere analog signals, and supports 250 VDC tachometer input. The enclosure is NEMA 1 for indoor use. It is equipped with a forced-air cooling fan. The overall dimensions are approximately 530 millimeters in height, 350 millimeters in width and 200 millimeters in depth. The total weight is about 18 kilograms. The product meets UL 508 and legacy CE standards.

Main circuit terminals include L1, L2 and L3 for AC power input, A plus and A minus for armature connection, F plus and F minus for field winding connection. Control terminals provide 24 VDC power supply, signals for start and stop, forward operation, analog speed reference and fault relay output. The front panel is fitted with LED indicators for power, running status and faults, as well as a keypad for parameter configuration.

It supports one-quadrant unidirectional operation, and external resistors are required for braking function. It features strong overload capacity to cope with frequent load fluctuations. Multiple feedback modes ensure stable speed regulation performance. It is built with comprehensive protection against overcurrent, overvoltage, overtemperature and field loss. Standard digital and analog interfaces enable easy connection and integration with automation systems.

It is suitable for unidirectional industrial equipment such as conveyors, mixers and extruders. It is commonly used on traditional production lines equipped with DC motors. It can serve as a direct replacement for outdated MaxPak Plus drives in legacy automation systems.

Install the drive inside a well-ventilated cabinet and reserve enough space for heat dissipation. Select appropriate cables for main circuit and control circuit wiring, and fasten all terminals tightly. Check input voltage and wiring condition before powering on. Set parameters in accordance with the data on the DC motor nameplate. Carry out regular quarterly maintenance to clean dust, inspect the cooling fan, terminals and indicator lights. Disconnect all power sources and wait for internal capacitors to fully discharge before conducting inspection and maintenance work.