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Under Voltage Relay
Application
Pradeep's Under & Over Voltage Relay - Model P-O/U 3 , has wide range industrial application for protection against problems of under and over voltage in 1 _ applications. It has settable limits for under and over voltage conditions beyond which connected load will be cut off thru' relay along with alarm indication. The unit can be set for manual or automatic mode of operation. This unit is ideal for D.G. set application. Housed in 96mm X 96mm sq. enclosure, the unit uses state of the art technology.
Typical applications for this unit are
- Water purification and treatment plants.
- Sugar industry - Pan alteration, Dialer automation.
- Primary & auxiliary temperature controller for boilers.
- Paper and pulp industry - washers, head box feed, bleachers etc.
- Chemical and petrochemical industry.
- Water pumping stations.
- Heat treatment furnaces.
- Power plants.
Seven segment LED display is provided for indication of settings and actual conditions
Principle of operation
Pradeep's under & over Voltage Relays are designed using basic principle of precise sensing of actual voltage w.r.to pre-set levels of permissible under & over voltage. In the event of actual voltage outside the pre-set range, along with LED indication of FAULT condition, the relays will operate to activate protection circuit. Common alarm is activated for under voltage or over voltage conditions, where as protection circuits are activated for individual conditions. With the help of state of the art microprocessor based electronic circuitry, accurate control over the entire range is achieved. (Details provided in specifications).
Salient Features
The microprocessor based under & over voltage relay, model) is distinguished for its features, construction, operation and cost effectiveness. The versatility of this model is a result of careful consideration and understanding of the wide spectrum of the user needs and convenience, whether during testing or online operation.This instrument is designed using state of the art Integrated Circuits (IC), and glass epoxy Printed Circuit Boards (PCB). It is easy to configure this instrument, as the same is very user friendly. The instrument incorporates a stabilized power supply and filter circuit for absorbing power supply transients, thus ensuring accurate control / and a stable display. The output is displayed prominently and has a viewing distance of more than 4 meter.
BURN-IN
Each instrument is tested and aged at ambient conditions for 48 hours in electrically energized condition prior to delivery as per Pradeep's norms for verification of design reliability. This practice ensures the unit's continued performance to specifications and to customer's satisfaction.
Type Tests: models are type tested at ERTL (West), STQC,
Govt. Of India for following:
- EMC Test: As per IEC - 61000 - 4 – 2 : 1995 for ESD and for HFD.
- Impact Shock Test as per IS 9000 (Pt. VII) : 1997.
- Cold and Dry Heat Test as per IS 9000 (Pt. 11) : 1977.
Additional important features
- Separate relay output for under & over voltage setting.
- Common relay output for any of the alarm condition.
- User selectable AUTO / MANUAL mode of resetting.
Technical Specifications
• Input voltage
110 V ac (Optional - 240 V ac)
• Under voltage range
88 V - 110 V ac (Optional 192V - 240 V ac)
• Over voltage range
110 V - 132 V ac (Optional 240V - 288 V ac)
• Resolution (setting)
1 volt over the entire range
• Accuracy Display
Seven segment RED LED digit display for voltage. (Actual voltage during normal operation. Set point while setting)
• Additional Indications
a) Red LED to indicate Power ON
b) Green LED relay operation
c) Orange LED for under & over voltage setting.
d) Blue LED for common relay operation. (Indication for one of the fault or both fault condition).
e) Red LED for AUTO reset operation.
Electrical Specifications
• Mains Supply
90 V to 260 V AC/DC Voltage
• Output
3 pair N/O ,N/C contacts - 3 relays. One each for under & over voltage conditions and one common output for both conditions.
• Relay Contact Rating
5 A at 240 VAC Res. Load, 100 W at 220 VDC.
• Terminals
Screw Caged, suitable for 0.2sq. mm. - 4 sq. mm. Solid Conductors
• Insulation
Insulation resistance >=100 M ohms at 500 V DC between each Terminal with earth
Voltage proof between all mains supply terminals shorted together & earth-No breakdown for one minute.
- Factory tested at 1.5 kV rms, 50 Hz.
- Subsequent field test at 0.5 kV rms, 50 Hz
• Power Consumption
10 VA max.
• Operating Conditions
Ambient temp. range. (-) 25°c. to 60°c.
Future
- Interfaces with conversion front panels to replace popular industry tapchanger controls.
- Serial communication ports with several on-board communication protocols.
- Two active serial communication ports, through RS-232 & RS-485.
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