ENGGA EVC800i Installation & Adjustment Manual

DESCRIPTIONS

The EVC800i is a 3 Phase full wave, pulse width modulated type of Automatic Voltage Regulator for regulating the voltage
of Brushless Generator.
Excitation power can be derived from a shaff mounted 3 Phase premanent generator (PMG) or stator winding or Auxillary
winding. Internal electrical isolation is created between the PMG inputs and sensing inputs of AVR. This isolation with the
PMG assures the performance of the AVR against Non linear loads and reduces the Radio frequency interference on the
generator terminals. The PMG supply enables the generator to maintain current into a short circuit.
Sensing to AVR is directly from main winding. This signal is used to control the power fed to the exciter stator (and hence
to the main rotor) to maintain the generator output voltage within the specified limits. Provision is made for the connection
of remote potentiometer allowing the user to find control generator output voltage.
Built up of generator output voltage is fully under control manner keeping excitation current within limits and with soft start.
A frequency measuring circuits continually monitors the speed of the generator to provide low speed protection to the
excitation system. It reduces generator output voltage proportionally with speed below an adjustable threshold as per volt
per hertz slope. This slope is provided adjustable and adjusted by DIP adjustment trimmer. In addition to DIP, an delayed
voltage recovery (DWELL) is provided to improve speed recovery time when generator is used in conjunction with Turbo
charge engines. Generator overload circuit cuts off the excitation power in the event of excessive load on generator or
malfunctions. AVR observe overload condition for 20 seconds and after that cuts off the field voltage.
This condition remains latched until the generator has stopped.
For connecting 2 or more generators in parallel, quadrature droop and analog inputs provide reactive power sharing
controls.

SPECIFICATIONS

Sensing Input
V - V for 220 Vac,
0 200
V - V for 400 Vac, 350 to 480Vac, 50/60Hz
0 380
Power Input
PMG : 160 to 250 V, 3 Ph, 50 to 400 Hz.
Main Winding : 160 to 250 V, 1 Ph
Auxillary : 160 to 250 V, 1 Ph
Output
Voltage : 180 Vdc on Input of 200 Vac
Current : Continuous 8 Amps
Built up Voltage
Residual Voltage : >4 Vac at AVR terminal
Voltage Regulation : < ±
Response Time : < 20 mSec
Field Resistance
7 to 18 Ohms.
Analog Input
Maximum Input : ± 5Vdc
Sensitivity : 1 Volt for 2 % generator Volts

AVR CONTROL FUNCTION

CONTROL: FUNCTION:
VOLT To adjust generator output voltage
STAB To prevent voltage hunting
UFRO To set under frequency Roll Off knee point
TRIM To match AVR input to Accessory Input
DROOP To set voltage Droop to 10% at 0.8 PF
EXC TRIP To set the over-excitation protection Trip level
DIP To adjust frequency related voltage Dip
DWELL To set the rate of voltage recovery time
SW1-ON To add fix response time
SW1-OFF Response time as per STAB Pot
SW2-ON To set UFRO knee point at higher frequency
SW2-OFF To set UFRO knee point at lower frequency
EVC800i AUTOMATIC VOLTAGE REGULATOR
Specification, Installation & Adjustment Manual
180 to 250Vac, 50/60Hz
1 % RMS
External Volts Adjustment
Atleast ± 10 % with 100 K Ohms 1 Watt trimmer
Droop Input
Burden : 0.25 Ohms
Maximum Sensitivity : 1 Amp for 10 % Droop
Maximum Input : 2 Amps
Under frequency protection
Factory setting : 47 Hz with Switch 2 OFF
Slope : 100 - 300 % down to 25 Hz
DIP : 1%Hz = 1%Volts to 1%Hz=3%Volts
DWELL : Adjustable from 0 to 45 V in 4 Sec Max.
Environment
Operating Temperature : -40 to +70 C
Storage Temperature : -40 to +90 °C
Relative Humidity : Max. 95%
Vibration : 3.3Gs @ 100-2K Hz
Dimension and Weight
175 mm L x 129 mm W x 37.5 mm H
XXXX
DIRECTION:
Clockwise increases output voltage
Clockwise increase in response
Clockwise increases knee point frequency
Clockwise increases AVR sensitivity
Clockwise increases the Droop
Clockwise increases the Trip level
Clockwise increases the Dip
Clockwise lengthens the recovery time.
SW1-ON : Increase in response time for 60 Hz
SW1-OFF : Response time for 50 Hz
SW2-ON : UFRO set at higher frequency
SW2-OFF : UFRO set at lower frequency
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57 Hz with Switch 2 ON
°
10/02/2015