HT INDUSTRIAL AUTOMATION LIMITED

STAMFORD Newage AvK Automatic Voltage Regulator AVR E000-23422 MX342

STAMFORD MX342 AVR Datasheet.pdf

Genuine STAMFORD AVRs: AS440, AS480, AS540, COSIMAT N+, DECS 100, DECS 150, DECS 250, DM110, DM710, DM730, MX321, MX322, MX341, MX342, UNITROL 1010, UNITROL 1020

Product Description

STAMFORD MX342 is a two phase sensed Automatic Voltage Regulator (AVR) and forms part of the excitation system for a STAMFORD brushless ac generator. This AVR features a linear volts / Hz slope down to 18Hz, and current limiting (when fitted with an additional CT).

DESCRIPTION: Stamford MX-342 voltage regulator, brand new, Original

PART NUMBERS: Stamford E000-23422 AVR, Stamford E000-23422/1P AVR

MANUFACTURER: Stamford (Cummins Generator Technologies)

ORIGIN: Manufactured in the U.K.

The STAMFORD AVR MX342 is an analogue, 2-phase sensing, permanent magnet generator (PMG) powered automatic voltage regulator (AVR) providing isolation from the effects of non-linear loads. It has improvised motor starting performance, sustained short circuit current and linear volts/Hz characteristic for variable speed applications.

This MX342 STAMFORD AVR features a linear volts / Hz slope down to 18Hz, and current limiting (when fitted with an additional CT). Excitation power is derived from a three-phase permanent magnet generator (PMG), to isolate the AVR control circuits from the effects of non-linear loads and to reduce radio frequency interference on the generator terminals. Sustained generator short circuit current is another feature of the PMG system.

The STAMFORD MX342 VOLTAGE REGULATOR senses the voltage in the main generator winding and controls the power fed to the exciter stator and hence the main rotor to maintain the generator output voltage within the specified limits, compensating for load, speed, temperature and power factor of the generator.

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 linearly with speed below a pre-settable threshold.

Soft start circuitry is included to provide a smooth controlled build up of generator output voltage. Uncontrolled excitation is limited to a safe period by internal shutdown of the AVR output device. This condition remains latched until the generator has stopped.

Technical Specification for STAMFORD Voltage Regulator MX342:

SENSING INPUT AT RATED SPEED Voltage 190-264 Vac max, 1 phase, 2 wire

Frequency 50-60 Hz

POWER INPUT (PMG) AT RATED SPEED Voltage 170-220 Vac max, 3 phase, 3 wire

Current 3A/phase Frequency 100-120 Hz

OUTPUT Voltage max 120V dc Current continuous 2.7 A Intermittent 6A for 10 secs. Resistance 15 ohms minimum

REGULATION +/- 1% average sensing (see note 1)

THERMAL DRIFT 0.03% per deg. C change in AVR ambient (note 2)

SOFT START RAMP TIME 3 seconds

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

EXTERNAL VOLTAGE ADJUSTMENT +/-10% with 1 k ohm 1 watt trimmer (see note 3)

UNDER FREQUENCY PROTECTION Set point 59.5 Hz (see note 4) Slope linear down to 18 Hz

UNIT POWER DISSIPATION 12 watts maximum

ANALOGUE INPUT Maximum input +/- 5 Vdc (see note 5)

Sensitivity 1v for 5% Generator Volts (adjustable) Input resistance 1k ohm

QUADRATURE DROOP INPUT 10 ohms burden Max. sensitivity: 0.07 A for 5% droop 0PF Max. input: 0.33 A

CURRENT LIMIT INPUT 27 ohms burden Max. sensitivity: 0.28 A (see note 6) Max. input: 0.33 A

OVER EXCITATION PROTECTION Set point 75 V dc Time delay 10 seconds (fixed)

ENVIRONMENTAL Vibration 20-100 Hz 50mm/sec 100Hz – 2kHz 3.3g

Operating temperature -40 to +700 C

Relative Humidity 0-700 C 95% (see note 7)

Storage temperature -55 to +800 C