Three-phase automatic voltage regulator KEMOT PROavr-25k 25 kVA 400 V

The KEMOT PROavr-25k three-phase automatic voltage regulator provides stabilized 230 V output (single-phase mode) and maintains balanced three-phase output in three-phase mode for installations with a 400 V nominal supply. With a rated power of 25 kVA, the unit is built on a toroidal transformer and servo-based regulation to correct undervoltage or overvoltage and supply a steady output within 230 V ±3% in single-phase operation. The regulator includes phase monitoring, over/under-voltage protection, overload, overheating and short-circuit protection, as well as a bypass switch and adjustable start delay.

Advantages

The stabiliser ensures high output accuracy (up to ±3%) using servo motor technology and a toroidal transformer for stable operation. It supports independent phase operation in single-phase mode and enforces phase balancing in three-phase mode, triggering a "PHASE ERROR" indication and output cut-off if a phase fault is detected. Additional functional features include a bypass switch for direct mains feeding, a DELAY start-up timer (6–180 seconds) to protect against high inrush currents, and a robust wheeled chassis for easier transport and positioning.

Suitable for

• Commercial and industrial three-phase equipment
• Office devices such as computers, monitors, printers and cash registers
• Home appliances with sensitive electronics: refrigerators, freezers, microwave ovens, induction hobs
• Audio/video systems, TVs and speakers
• Heating pumps and central heating systems
• Backup generators and small workshops

Key specifications

• Model: KEMOT PROavr-25k (MPN URZ3437-25)
• Rated power: 25 kVA
• Nominal voltage (three-phase): 400 V
• Output voltage accuracy (single-phase): 230 V ±3%
• Control method: servo motor with toroidal transformer
• Delay start range: 6–180 seconds
• Protections: over-voltage, under-voltage, overload, overheating, short-circuit, phase error detection
• Features: bypass switch, four transport wheels

How to use

Install the regulator in a dry, ventilated location and connect it to the incoming three-phase supply according to local electrical codes. For three-phase operation, ensure all three input phases are connected and balanced; the unit will monitor each phase and disable output with a phase error if imbalance or disconnection is detected. Use the DELAY selector to set a start delay between 6 and 180 seconds when connecting equipment with high starting currents. The bypass switch can be used to feed mains directly while the stabiliser is isolated for maintenance.

Usage recommendations

For reliable long-term operation, schedule periodic inspections of electrical connections and ventilation paths, avoid exposing the unit to moisture or extreme temperatures, and select an installation location that allows access to the bypass and delay controls. If used with generators, verify compatibility with the generator’s voltage and phase characteristics before continuous operation.