HT INDUSTRIAL AUTOMATION LIMITED

Stamford Automatic Voltage Regulator AVR MX322

STAMFORD MX322 AVR Datasheet.pdf

Replacement model for Stamford Generator MX322 AVR in stock!

The Brands mentioned here are for reference purpose only, our parts can exactly replace the original ones.

The STAMFORD MX322 analogue, 3-phase sense Automatic Voltage Regulator AVR and forms part of the excitation system for a brush-less alternator. Excitation power is derived from a 3-phase permanent magnet generator (PMG), to isolate the MX322™ AVR control circuits from the effects of non-linear loads and to reduce radio frequency interference on the alternator terminals.

Sustained alternator short circuit current is an additional feature of the PMG system.

The MX322 STANMFORD AVR senses the voltage in the main alternator winding and controls the excitation to maintain the alternator output voltage within the specified limits, compensating for load, speed, temperature and power factor of the alternator. Three phase RMS sensing is employed for superior voltage regulation.

The STAMFORD AVR MX322 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.

TECHNICAL SPECIFICATION of STAMFORD MX322 Voltage Regulator AVR:

SENSING INPUT Voltage 170-264V ac max, 2 or 3 phase Frequency 50-60 Hz nominal

POWER INPUT (PMG) Voltage 170-220V ac max, 3phase,3wire

Current 3A/phase Frequency 100-120 Hz nominal

OUTPUT Voltage max 180V dc

Current continuous 4.2A (see note 1) Intermittent 9A for 10 secs.

Resistance 15 ohms minimum REGULATION +/- 0.5% RMS with 4% engine governing (see note

2) THERMAL DRIFT 0.02% per deg. C change in AVR ambient (note

3) SOFT START RAMP TIME 0.4 - 4 seconds

TYPICAL SYSTEM RESPONSE AVR response 10 ms Filed current to 90% 80 ms Machine Volts to 97% 300 ms

EXTERNAL VOLTAGE ADJUSTMENT +/-10% with 5 k ohm 1 watt trimmer (see note

4) UNDER FREQUENCY PROTECTION Set point 95% Hz (see note 5) Slope 100-300% down to 30 Hz Max. Dwell 20% volts/S recovery

UNIT POWER DISSIPATION 18 watts maximum

ANALOGUE INPUT Maximum input +/- 5 Vdc (see note 6) Sensitivity 1v for 5% Alternator Volts (adjustable) Input resistance 1k ohm

QUADRATURE DROOP INPUT Burden 10 ohms Max. sensitivity: 0.22 A for 5% droop 0PF Max. input: 0.33 A

CURRENT LIMIT INPUT Burden 10 ohms Sensitivity range: 0.5 – 1A

OVER VOLTAGE DETECTOR INPUT Set point: 300V Time delay: 1 Sec (fixed) CB trip coil volts: 10-30 vdc CB trip coil resistance: 20-60 ohms

OVER EXCITATION PROTECTION Set point 75 V dc Time delay 8-15 seconds (fixed)

ENVIRONMENTAL Vibration 20-100 Hz 50mm/sec 100Hz – 2kHz 3.3g Operating temperature -40 to +70°C Relative Humidity 0-70°C 95% (see note 7) Storage temperature -55 to +80°C