Electrical Appliances & Electrical Machines are made to work with optimum efficiency at rated voltage. They work at particular voltage range, it may be +-5% or +-10% of rated voltage. Voltage Out of the range leads to decrease in efficiency, decrease in useful life & malfunctioning in operation.

System must work at defined voltage range; failure of this leads to large overcurrent, overheating, degraded useful life, insulation Damage, reduced performance. Voltage stability is most important in electrical system That's why we need so important Voltage stabilizer for a stable voltage. In this post we are going to discuss the technical specifications of 25KVA Servo control voltage stabilizer.

25KVA ASC Voltage Stabilizer Made by Fuji Electric

25KVA ASC Voltage Stabilizer by Fuji Electric
540×600×1075[L×B×H(mm)] with ingress protection of IP-20

TECHNICAL SPECIFICATIONS

Capacity= 25KVA
Input Voltage range = 360-460 (V)
Output Voltage = 415
Input Frequency= 47-53Hz
Max. Current= 35 Amps
Control type= Digital microcontroller based
Correction speed = 70V/Second
Reset= Manual/Auto reset with time delay & programmable
Response time = 10micro Sec
Audio Alarm for tripping conditions
Nature of cooling = Natural Air
Effect of pf - Nil
Waveform distortion - Nil
Efficiency > 98%
Cabinet color = Siemens Grey
Servo motor drive = Rugged AC step synchronous motor
Operating Temperature = 0-45°C
Degree of protection = IP20

HMI (Human Machine Interface)

HMI of Voltage Stabilizer

HMI has two displays

1st is VF meter for voltage & frequency

Input, Output & Hz(frequency) LEDs are present on this meter along with it phase representing Red, Yellow & blue LEDs are present. We can check phase & line voltages on both Input & Output sides by pressing set button continuously.

For example:

We press set button for 1st time, Input LED & Red LED get ON. This means display showing the phase voltage of RED phase on Input side.
When we press set button for 7 times, Output & Red-Yellow LEDs are ON. This means display showing the line to line voltage between red & yellow on output side.

2nd is Ammeter for ampere(current) reading

Load current on all the three phase; can be checked on this 2nd display.

Red, yellow, blue LEDs are phase representing LEDs on side of display.

These all the parameters Input phase voltage, Input line Voltage, Output phase voltage, Output line voltage, frequency & line current in all the three phases can be seen one by one by pressing MENU KEY continuously.

Push Button keys on HMI

Push Buttons/ keys

HMI has three buttons MENU, START, STOP.

There is two modes to operate these three keys which are RUN Mode & SET mode.

To enter into RUN mode there is no need to press any button because it is the default mode.

To enter into SET mode; press the 3mm tactile switch which is placed inside stabilizer cabin.

"SET mode is used to change the parameters value on the other hand run mode is used in running conditions to select the parameter."

STOP KEY:

Run mode- To switch OFF output load

Set mode- To edit the selected digit

START KEY:

Run mode- To switch ON output load

Set mode- To select the digit

MENU KEY:

Run mode-To view the running parameters like voltage, current & frequency.

Set mode- To view the settings.

LOG KEY:(This key present inside the stabilizer on PCB board)

RUN mode- To view the error log in

SET mode- To calibrate the phase voltage & phase to phase voltage

Fault/Signal LEDs on HMI

FAULT/SIGNAL LEDs

On right side of HMI schematic diagram is present. Fault/signal LEDs are present on this diagram. LED for voltage on each phase is present on both input & output sides, This LED shows whether voltage on the side is present or not.

OVL LED

This LED is present on all three outputs which represents overload on each phase.

NEUTRAL/EARTH FAULT LED

To indicate neutral fault condition.

PHR LED

To indicate phase reversal.

PROTECTIONS

1. Electronic Over & under voltage trip with time delay for input & Output.
2. Electronic overload protection & short circuit protection through MCB.

3. Surge Arrester/ RF suppressor(optional)

4. Phase reversal protection & cutoff.

5. Single phase prevention & cut off.

6. Neutral failure protection

7. Frequency cut off protection.

8. Earth neutral voltage cut off protection.

9. MCB & Manual Bypass (A 3 pole 50 Amps MCB is installed for switching & short circuit protection. Stabilizer can be bypassed with a Manual BYPASS switch )

MCB & BYPASS switch on voltage stabilizer

CONNECTION BOX

Connection box is present at back downside of stabilizer.

1st left point is earth after that 3phase+ Neutral input points are present. After the input terminal, Output terminals are provided which is 3phase & neutral.