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Stamford MX321 Automatic Voltage Regulator AVR | AYN Automation

Stamford MX321 Automatic Voltage Regulator AVR


PART NUMBER: E000-23212/1P

Voltage 190-264V ac max, 2 or 3 phase
Frequency 50-60 Hz nominal


Voltage 170-220V ac max, 3 phase, 3 wire
Current 3A/phase
Frequency 100-120 Hz nominal

Voltage max 120V dc
Current continuous 3.7 A (see note 1)
Intermittent 6A for 10 secs.
Resistance 15 ohms minimum

The MX321 is an analogue, 3-phase sensing, permanent magnet generator (PMG) powered automatic voltage regulator (AVR) providing isolation from the effects of non-linear loads, improved motor starting performance and sustained short circuit current.

MX321 is a three phase sensed Automatic Voltage Regulator and forms part of the excitation system for a brush-less generator. Excitation power is derived from a three-phase permanent magnet generator (PMG), to isolate the AVR control circuits from the effects of nonlinear loads and to reduce radio frequency interference on the generator terminals. Sustained generator short circuit current is another feature of the PMG system.

The AVR senses the voltage in the main generator winding and controls the excitation to maintain the generator output voltage within the specified limits, compensating for load, speed, temperature and power factor of the generator. Three phase RMS sensing is employed for superior voltage regulation.

Adjustable Soft start circuitry is included to provide a smooth controlled build up of generator output voltage.

A frequency measuring circuit continually monitors the shaft speed of the generator and provides under-speed protection of the excitation system by reducing the generator output voltage proportionally with speed below a pre-settable threshold. A further enhancement of this feature is an adjustable volts per Hertz slope and voltage recovery time, to improve the response of turbo charged engines.

Current limiting may be included to allow control over the amount of sustained short circuit current.

Maximum excitation is limited to a safe period by internal shutdown of the AVR output device. This condition remains latched until the generator has stopped.

The AVR includes an over-voltage protection feature with internal shutdown of the AVR output device, plus the ability to trip an optional excitation circuit breaker if required.

Provision is made for the connection of a remote voltage trimmer, allowing the user fine control of the generator's output.

An analogue input is provided allowing connection to a Newage Power Factor controller or other external device with compatible output.

The AVR has the facility for droop CT connection, to allow parallel running with other similarly equipped generators

Download AVR Datasheet

Packaging and Handling
  • 1 Business day for handling and packaging
  • Profession quality packing
  • Free shipping on all orders above $250 (except heavy items).
  • UPS, FedEx or DHL Expedited International Shipping.


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