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Mitsubishi Electric MELPRO-A Series Instruction Manual

Earth fault overcurrent relay
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JEP0-IL9555

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Summary of Contents for Mitsubishi Electric MELPRO-A Series

  • Page 1 Request Ensure that this Instruction Manual is delivered to the end users and the maintenance manager. JEP0-IL9555...

  • Page 2: Safety Precautions

    － Safety precautions － Before installation, operation, maintenance, and inspection, please be sure to read this instruction manual and all other attached documents thoroughly in order to work safely with the equipment. Please ensure that you fully understand the equipment, safety information, and precautions that need to be taken before working with the equipment.

  • Page 3: Maintenance And Inspection

    ＊The equipment must only be operated and handled by qualified personnel. Otherwise, there are risks of electric shock, injury, failure, malfunction, and maloperation. ＊Handling and maintenance of the equipment must only be carried out after gaining a thorough understanding of the instruction manual.
  • Page 4 MITSUBISHI ELECTRIC CORPORATION prior to such applications. If the user applies MITSUBISHI ELECTRIC CORPORATION products to such applications without any contact to our technical section, MITSUBISHI ELECTRIC CORPORATION shall not be liable for any items and not be insured, independently from mentioned in this clause.
  • Page 5 5. Onerous repair term after discontinuation of product (1) MITSUBISHI ELECTRIC CORPORATION shall accept onerous product repairs for 7 years after production is discontinued. (However, the product which was made over 15 years is recommended to replace.) (2) Product supply (including repair parts) is not available after production is discontinued.

  • Page 6: Ratings And Specifications

    MGR-A3 Series Earth Fault Overcurrent Relay [Standard: JIS C 4601 (1993)] Features 1. Wide setting range enables flexible protection 4. Good operability and visibility design is coordination. adopted. The numerical display turns on for 3 2. Reset method of output contacts can be seconds when the setting value is changed, switchable between auto-reset and self-hold which enables to check setting values easily.
  • Page 7 Characteristics (MGR type relay ＋ MZT type ZCT combination) Item Characteristics Ambient temperature: –20 to +60℃ (Under the state where dew condensation or freezing does not occur) Relative humidity: 30 to 80% on daily average Standard use Altitude: 2000m or lower conditions ・The state where abnormal vibration, shock, and inclination are not applied.
  • Page 8 Voltage tripping type Current tripping type DC110V 15A (L/R=0ms) Making DC220V 10A (L/R=0ms) (Closing) Breaking (Opening): AC110V 60A Contact capacity AC110V 10A (cosφ=0.1) The 2Ω (power factor = 0.5) loads in parallel to DC110V 0.3A (L/R=7ms) Breaking the contacts AC110V 5A (cosφ=0.1) (Opening) AC220V 1A (cosφ=0.1) Note) For details, refer to JIS C 4601 (1993).

  • Page 9: Operating Description

    Structure Test button RUN indicated LED (Green) By turning the indicator select It shows the result of self- switch to "TEST" and pushing monitoring. It lights up in "TEST" button for 2 seconds or normal condition. more, output contact can be forced to operate (except for Numerical display LED the case of LOCK setting).

  • Page 10: Internal Connection Diagram

    2. RUN display (Self-monitoring function) ⑤Output contact setting (MGR-A3V-R only) This relay monitors control voltage, electric It displays the setting condition of output contact circuit, and program data at all time. The RUN LED in accordance with the setting switch of SW2. (green) lights up in the normal condition.
  • Page 11 External connection diagram (Example) 【Tripping route】 MGR-A3T-R R S T (1) When a earth fault occurs, the CB is tripped through the sequence from the power source to S , contact, T tripping coil, T , contact, and to S (2) When a short circuit fault Another current limiter...
  • Page 12 MGR-A3V-R R S T 【Tripping route】 (1) When a earth fault occurs, the contact between c and b opens, then trip coil of CB is de- energized and make CB trip. (2) When a short circuit fault occurs, the trip contact between T1 and T2 closes, then trip ℓ...
  • Page 13 Precautions for design and installation ＜Connection＞ ＜Precautions for use＞ (1) Test terminals of ZCT: The test terminals of ZCT (1) This ground relay uses only the current of the zero- (kt and ℓt) are used only for the operation test phase current transformer...
  • Page 14 Earth fault relay and shield grounding of cable When installing the earth fault relay, pay attention to the location of shield grounding point of the cable as shown in the regulations of JEAC 8011. Whether or not the cable can be protected against a earth fault and the response of the earth fault relay to the charging current in the event of an external fault depend on the method of installing the shield grounding.
  • Page 15 【Lead-out cable】 Effect of charging Grounding protection of current (Ic) in the Shield grounding method Consideration Evaluation cable itself event of external grounding fault ○ △ If the charging ｹｰﾌﾞﾙ 電源側 Within the protection Charging current flows current is large, ﾍｯﾄﾞ...

  • Page 16: Handling Precautions

    Handling precautions 1. Panel mounting if the setting change is unavoidable, please press the ①Be sure to connect the "E" terminal of the relay to D- CPU reset button in order to lock the relay function. class grounding. ③Don't leave rotary switches with halfway (indefinite) state.
  • Page 17 4. Operation characteristic control point Perform the test periodically according to the following test conditions and criteria. Test condition Test item Criteria Input Operation value Operating time ±10% of setting Operation value － Each setting Instantaneous value Instantaneous － 0A → 130% of setting 0.2s 0.1～0.3s 0.3s or more...

  • Page 18: Terminal Layout

    Terminal layout × × × × MGR-A3V-R MGR-A3T-R Do not connect to the "×" terminals, or the relay may not operate properly. Fig. 3-10 Terminal layout JEP0-IL9555...
  • Page 19 Handling of the cover 1. Opening and closing Please open the cover by placing your fingertip on the convex part in the right side of the cover as shown in Fig. 3-11. Fig. 3-11 2. How to replace the cover ･Removing the cover Open the cover, and lightly push up the upper side of the cover from the inner surface.

  • Page 20: External Dimensions And Panel Cut-Out

    External dimensions and Panel cut-out φ140～φ142 2-M6 screw 14-M3.5 screw 2-φ7 hole Minimum pitch Fig. 3-13 MGR-A3V/A3T-R (Unit: mm) Same as the center of panel cut-out Improvement on the reliability of protection function Any parts and materials applied to the protection relay have limited lifetime which will bring the degradation to the relay.
  • Page 21 HEAD OFFICE ： 7-3 MARUNOUCHI 2-CHOME, CHIYODA-KU TOKYO, 100-8310, JAPAN First edition: Mar. 2021...

This manual is also suitable for:

Melpro mgr-a3v-rMelpro mgr-a3t-r

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