Stamford Automatic Voltage Regulator Mx321

Stamford Automatic Voltage Regulator Mx321

Product description:

Item specifics

Brand Name:
Model Number:

Product Description

Item specifics

Place of Origin:
China (Mainland)
Brand Name:
Model Number:

Product Description

Product Details:

Place of Origin Guangdong, China (Mainland)
Brand Name Stamford
Model Number MX321
Usage JIW
Phase Three Phase
Current Type AC
weight 0.755kg
purpose brushless generator

Payment & Shipping Terms:

Price: Get Latest Price
Minimum Order Quantity: Negotiable Trial Order
Minimum Order Quantity: 5 Piece/ PiecesTrial Order
Port: shenzhen
Packaging Details: standard carton. size of packing: 21cm x17.5cm x7cm
Delivery Time: in stock
Payment Terms: T/ T, Western Union
Supply Ability: 1000 Piece/ Pieces per Month

Stamford MX321

3 Phase Sensing Permanent Magnet Generator type voltage regulator is a compatible replacement for Newage Stamford MX321 and Onan 305-0823.

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

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

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



  • Voltage Regulation ( ±0.5% RMS

  • For Use In Parallel Operation

  • RAMP, DIP, DWELL, DROOP, RMS, U/ F, Over Voltage & Over Excitation Adjustment Functions

  • Over Exc. / Over Volt. & UFRO LED Indicators

  • Current Limiting Function

Sensing input


190 -264V ac max, 2 or 3 phase


50-60 Hz nominal

Power input (PMG)


190-220V ac max. 3 phase , 3 wire


3A/ phase



Max 120V dc


Continuous 3.7 A ( see note 1 )

Intermittent 6A for 10 secs


15 ohms minimum


+/ - 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 )


100-300% down to 30 Hz

Max Dwell

20% volts/ s recovery

Unit power dissipation

18 watts maximum

Analogue input

Maximum input

+/ - 5V dc (see note 6)


1v for 5% generator volts (adjustment )

Input resistance

1k ohm

Quadrature input

10 ohms burden

Max sensitivity

0.22 A for 5% droop OPF

Max input

0.33 A

Current voltage detection input

Set point

300V .time delay: 1 sec (fixed )

CB trip coil volts

10 – 30 V dc

CB trip coil resistance

20-60 ohms

Over excitation protection

Set point

75 V dc

Time delay

8-15 seconds ( fixed )



20 – 100 Hz 50mm/ sec

100Hz – 2k Hz 3.3g

Operating temperature

-40 to +70 degree

Relative humdity 0-70 degree

95% (see note 7 )

Storage temperature

-55 to + 80 degree

Our Products as follow:

Stamford AVR: MX341, MX321, SX440, SX460, AS440

Leroy Somer AVR: R230, R438, R448, R449

Marathon AVR: SE350

Siemens/ Basler AVR: AVC63-7/7F, AVC63-7-1A, AVC63-7FS

Universal AVR: GAVR-8A, GAVR-12A, GAVR-15A

Brush Type AVR: GB100, GB120, GB130B, GB160/170, GB160C/ 170C

Others: EA05A, KXT-2WC, KXT-2WC1B

Deep sea controller: DSE51105120501k, GTR-168

Cummins engine governor: ESD5500E, ESD5111, EFC3044196

Cummins Actuator: 34083243408326, ADC225

Packaging Details

Unit Type:
Package Weight:
0.755kg (1.664lb.)
Package Size:
21cm x 17cm x 7cm (8.27in x 6.69in x 2.76in)