MOTOR PROTECTION RELAY

Transcription

1 MOTOR

2 Introduction Prok dv s make uses the state-ofthe-art Microcontroller based measurement techniques for providing protection for Motors up-to 75HP. The comprehensive protection features of the relay makes it ideal for Motor protection. The heart of the relay is microcontroller based reliable hardware with special algorithms to calculate the tripping time. The relay continuously monitors the Three Phase Currents to build the thermal replica of the Motor. This thermal replica is used to protect the Motor against Thermal Over Loads. The does not require external Current Transformer (CT) for its operation. The three phase R, Y and B cables are made to pass through the CT hole which is in the relay. The built in CT s takes care of stepping down of the Currents to the required level. The stepped down three phase Currents are continuously monitored by the relay to detect any abnormal behavior of the Motor and to make tripping decision. The following protections offered by Prok dv s make Microcontroller Based Motor Protection Relay : ŸThermal Over Load Protection ŸUnbalance Protection ŸPhase Reversal Protection ŸEarth Fault Protection ŸLocked Rotor Protection ŸSingle Phasing Protection ŸUnder Current Protection Features ŸAccurate and Real Time TRUE RMS measurements. ŸSelectable Thermal Trip Time characteristics Class - 10A, 10, 20 & 30. ŸPre-alarm at 105 % of Im by Potential Free Output Contacts. ŸThermal Memory. ŸContinuous display of measured Healthy / Fault Currents. ŸFault records up to Previous 999 faults and 20 Previous On-Board faults with Date and Time stampings. ŸIncrement / Decrement Key and Mode / Set key in front facia. ŸFail safe / Non-Fail safe Feature. ŸOperational and Type / Nature of Fault indications through OLED. ŸCommunication through Modbus protocol with RS-485 Port. ŸEnable / Disable option for Earth Fault, Under Current, Locked Rotor, Phase Unbalance Protection. ŸVarious Models with Current ratings. ŸCompact and Reliable. ŸManual TEST / RESET Facility.

3 Applications ŸProtection of LV Motors up-to 75HP in Motor Control Centres. Specifications 1) Thermal Over Load Protection: Over Load Current Setting Range 2.0Amps 96.0Amps in 4 ranges as explained in SL.13 Trip Time Characteristics Class 10A, 10, 20 &30 as per IEC Pre-alarm at 105 % of Im by One set of Potential Free output Contacts Thermal Memory Provision 2) Earth Fault Protection Earth Fault Current Setting Range10% to 50% of Im, in steps of 1% (20% - Factory Set) Trip Time Delay 0.1Sec to 5.0Sec in steps of 0.1Sec (0.1Sec - Factory Set) 3) Phase Unbalance Unbalance Current Setting Range 10% to 50% of Im, in steps of 1% (40% - Factory Set) Trip Time Delay 0.1Sec to 5.0Sec in steps of 0.1Sec (2.0Sec - Factory Set) 4) Locked Rotor Protection Locked Rotor Current Range Greater than 3 times of Im (LR Setting can be tailored to customer specific) Trip Time Delay 0.1Sec to 5.0Sec in steps of 0.1Sec (1.0Sec - Factory Set) 5) Under Current Protection Under Current Setting Range 10% to 50% of Im, in steps of 1% (50% - Factory Set) Trip Time Delay 0.1Sec to 5.0Sec in steps of 0.1Sec (3.0Sec - Factory Set) 6) Loss of Phase / Single Phasing Applicable when Im Greater than 35% Trip Time Delay Fixed (0.5Sec - Factory Set) 7) Phase Reversal Monitoring Trip Time Delay Fixed (0.5Sec - Factory Set)

4 8) Contacts: 1NO/NC AC, DC Potential-Free Output Contacts for Overload Prealarming Circuit. 2NO/NC AC, DC Potential-Free Output Contacts for Tripping Circuit for all seven Faults. 9) Auxiliary Power Supply : V AC / DC 10) Trip Accuracy : As per IEC Trip Class 10A, 10, 20, & 30 11) Pick-Up Accuracy : +/- 12.5% 12) Reset : Manual 13) Models : -1 (2.0Amps-16.0Amps) -2 (16.0Amps-32.0Amps) -3 (32.0Amps-64.0Amps) -4 (64.0Amps-96.0Amps) -11 (1Amps Secondary) -15 (5Amps Secondary) 14) Prok dv s Series is available in TWO Versions as 1) Fail safe 2) Non-Fail safe (Non-Fail safe Factory Set) 15) Communication is through RS-485 MODBUS Protocol (HALF DUPLEX), Baud rate: 9600 bps With Max 30 Devices 16) Mounting : DIN 17) Dimensions in mm : 70X75X109 (WXHXL) 18) Operating Temp : 0⁰c to +60⁰c Protections Offered By Series Prok dv's make Series is designed to offer the following protections to Low Voltage (LV) 3-Phase induction motors rated up to 75HP. Whenever a Relay detects any of the following faults, Prok dv's make having two sets of output changeover potential free contacts, One set of changeover potential free contacts is dedicated for pre-alarm circuit and another set of changeover potential free contacts for Tripping circuit which is common for all the seven faults.

5 1. Thermal Over Load Protection: Prok dv's make continuously measures and displays Real Time Motor Current of all the Three Phases. When the Motor Current exceeds the set value Im, the relay issues a trip command after the calculated time elapse (Based on selection of trip Class). The relay displaying the Type / Nature of fault with magnitudes. Exclusive One Set of potential free contacts is provided in the relay for pre-alarm circuit when the Motor Current exceeds 105% of Im and the relay has two sets of potential free contacts for tripping circuit. The relay monitors the Currents continuously and using this data it builds Thermal replica of the Motor and monitoring the Thermal status of the Motor. This information is used to protect the Motor against Thermal Over Loading. 2. Earth Fault Protection: Prok dv's make senses the Zero sequence components of the TRUE RMS Currents are measured simultaneously and detecting the Earth Faults. The moment the Earth Fault crosses the Threshold Set value, an trip command is given by the relay to the trip circuit with a time elapse. The Earth Fault phenomenon is predominant in the Motor and Motor Control Centres, Hence protection against Earth Fault is necessary. uses the proven Holmgreen technique for detection of Earth Fault in the Motor. 3. Unbalance Protection: Prok dv's make measures and monitors all the Three Phase Currents and extracts the Unbalance Currents presents in the Three Phase Motor circuit. The moment an Unbalance Current is detected and if it crosses more than the Set value, the relay is activated in tripping the circuit. 4.Locked Rotor Protection: Prok dv's make detects Locked Rotor condition i.e. Motor not withstanding over loads beyond 3times as per Thermal withstand time characteristics and this is predominantly observed in old unused and rewound Motors. In the Locked Rotor Condition if the Motor Current crosses 3times Im the relay is activated in tripping the circuit with a time elapse. 5. Under Current Protection: Prok dv's make detects the Under Current Fault in a situation that sudden load Throw-Off or Loss of load, resulting in dry run of Motor. During the sudden loss of load the Motor takes low Current i.e. Under Current and if this value crosses the Set value the relay trips the circuit with a time elapse. 6.Loss of Phase / Single Phasing: Prok dv's make detects the Loss of Phase / Single Phasing in a Motor circuit. Motor burnouts are predominant due to Single Phasing or Loss of Phase at the main source / HT side and Fuse failure at the Motor Circuit. The Single Phasing / Loss of Phase is sensed by the relay and trips the circuit with a time elapse. 7.Phase Reversal: Prok dv's make monitors the Phase Sequence Currents and detects the Phase reversal and trips the circuit with a time elapse.

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7 DIGITAL EARTH LEAKAGE DIGITAL MICROCONTROLLER / MICROPROCESSOR BASED EARTH LEAKAGE (ELR) WITH CORE BALANCE CURRENT TRANSFORMER (CBCT / ZCT) MPEL SERIES IEEE Device Code-64 ISO Prok Devices Private Limited SIMHADRI,No.2930, 14 th Cross, Banashankari II nd Stage, Off K.R. Road, Bengaluru Karnataka,India Tel: / / Fax: For Marketing Information & Assistance enquiry@prokdvs.com marketing@prokdvs.com For Product Information & Technical Details info@prokdvs.com For Service Information service@prokdvs.com