Mitsubishi Electric MELPRO MOC-A3T-R Instruction Manual Download Page 2

2

                                     

   

JEP0-IL9553

 

  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. Safety precautions are classified as “Caution.” 

 

Caution 

The case where a dangerous situation can arise and there is the possibility that moderate   
or minor injuries can occur, or property damage can take place if the equipment is handled 
incorrectly. 

 

 
Furthermore,  even  with  items  described  as 

 Caution,  there  is  the  possibility  of  serious  consequences 

depending on the situation. All of the described contents are important. Therefore, be sure to comply with them. 

 

Caution

 

1.

 

Installation and Wiring work 

 

Caution 

Ensure  that  the  equipment  is  mounted  and  connected  correctly.  Otherwise,  there  are  risks  of  failure,  burning,  or 

maloperation. 

Securely tighten the terminal connection screws. Otherwise, there are risks of failure and burning. 
For tightening torque of screws, refer to the following Table. 

Material 

Nominal 

dia. 

Standard value of 

torque 

Allowable range 

Place of use 

Steel 

M3.5 

1.10N

11.2kgf

cm

 

0.932

1.27N

9.5

12.9kgf

cm

 

Terminal block 

Steel 

M4 

1.65N

16.8kgf

cm

 

1.39

1.89N

14.2

19.3kgf

cm

 

Drawer  fixing  screw  of  unit-drawer  type 
(RD type) 

Steel 

M6 

5.49N

56kgf

cm

 

4.71

6.37N

48

65kgf

cm

 

Fixing screw for mounting 

Steel 

M10 

26.5N

270kgf

cm

 

22.6

30.4N

230

310kgf

cm

 

MPD-3C bottom screw 

Brass 

M4 

0.961N

9.8kgf

cm

 

0.824

1.11N

8.4

11.3kgf

cm

 

MZT primary terminal (k, ℓ) 
MPD-3T terminal 

The equipment must be correctly grounded using the designated grounding terminals where they exist. Failure to do so 
may lead to the risk of electric shock, equipment failure, malfunction or failure to operate. 

Ensure that the equipment is connected correctly in accordance with the details (e.g.: polarity or phase sequence) shown 
on the connection terminals. Otherwise, there is the risk of failure, burning, malfunction, or maloperation. 

All power supplies and transformers to the equipment must be of suitable capacity and rated load to avoid the risk of 
malfunction and maloperation. 

Be sure to return all terminal covers, protection covers to their original positions once any work is complete. If they remain 
uncovered there is a risk of electrical shock. 

The appropriate connectors must be used to ensure compatibility with the connector terminals to avoid the risks of failure 
or fire. 

When inserting subunit into the case, please ensure that there is no gap between front side of the subunit and the case. 
In addition, tighten lower screw surely. If the subunit is inserted inadequately, there are risks of malfunction or generation 
of heat.

 

 

2.

 

Operating and Setting 

The equipment must be used within the following range limits. Otherwise, there is a risk of reducing the performance and life of 
the product. 

Variation range of auxiliary power supply voltage 

Within –15 to +10% of the rated voltage 

Frequency variation   

 

 

Within ±5% of the rated frequency 

Ambient temperature  

 

 

–20 to +60

 

(under the state where dew condensation or freezing does not occur) 

Relative humidity 

 

 

 

30 to 80% on daily average 

Altitude 

 

 

 

 

2000m or lower 

The state where abnormal vibration, shock, inclination, magnetic field(

) are not applied 

The state where it is not exposed to harmful smoke/gas, saline gas, water droplet or vapor, excessive dust or fine powder, 
explosive gas or fine powder, wind & rain 

(

) If there is a large amount of current on main circuit surrounding the relay, the operation indicator may be magnetized and 

turned from black to orange color. In that case, please shield back of the relay by iron plate. 

 

 

Summary of Contents for MELPRO MOC-A3T-R

Page 1: ...1 JEP0 IL9553 Request Ensure that this Instruction Manual is delivered to the end users and the maintenance manager ...

Page 2: ...t Failure to do so may lead to the risk of electric shock equipment failure malfunction or failure to operate Ensure that the equipment is connected correctly in accordance with the details e g polarity or phase sequence shown on the connection terminals Otherwise there is the risk of failure burning malfunction or maloperation All power supplies and transformers to the equipment must be of suitab...

Page 3: ...el 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 Otherwise there is the risk of electric shock injury failure malfunction or maloperation When replacing the equipment use a product of same model rating and specifications Other...

Page 4: ... special damages and secondary damages whether foreseeable or not compensation for accidents and compensation for damages to products other than MITSUBISHI ELECTRIC CORPORATION products and other tasks 4 Applications of products 1 The user is requested to confirm the standards the regulations and the restrictions which should be applied in case of utilizing this product and another one in combinat...

Page 5: ...ecommended to replace 2 Product supply including repair parts is not available after production is discontinued 6 Changes in product specification The specification given in the catalogue manuals or technical documents are subject to change without prior notice 7 Scope of service The technical service fee such as engineer dispatching fee is excluded in the price of our products Please contact to o...

Page 6: ...eous sensitivity 20 SW3 OFF SW4 OFF 40 SW3 OFF SW4 ON 60 SW3 ON SW4 OFF 80 SW3 ON SW4 ON Caution If the operation value of instantaneous element is set to 10A the sensitivity setting of 20 is not allowed If you do that the relay operates as 2 step characteristic Operating time characteristics Time lag Extremely inverse EI SW5 OFF SW6 OFF Very inverse VI SW5 OFF SW6 ON Normal inverse NI SW5 ON SW6 ...

Page 7: ...on CT Normal 3 5VA Operating 4 5VA Case Munsell color Unit fixed type Fig 1 11 0 6B7 6 0 2 Unit drawer type Fig 1 12 0 6B7 6 0 2 Unit fixed type Fig 1 11 0 6B7 6 0 2 Mass Approx 1 0kg Approx 1 1kg Approx 1 0kg shows factory setting ...

Page 8: ...17 1 80 12 1 80 17 1 80 12 1 80 12 Instantaneous element 50ms or less Input 200 of setting value Refer to Fig 1 1 3 for characteristic example Overshoot time characteristics Time lag element Dial 10 Input 1000 of setting value Applied time 90 of theoretical operating time The relay shall not operate Temperature characteristics Time lag element Ambient temperature 20 or 60 Operation value Within 20...

Page 9: ...for 2 seconds Between all CT circuits and external box Between all control circuits and external box Setting Minimum operation value and minimum operating time Input 80 of time lag element operation value Criteria No malfunction Radio disturbance Intermittently irradiate radio waves to the front panel of the relay with a transceiver of 150MHz or 400MHz band 5W output from a distance of 0 5m Settin...

Page 10: ...s Current multiples to the setting I EI characteristic 2 5 20 0 25 0 5 1 1 5 2 2 5 5 10 20 Dial D 0 01 0 1 1 10 100 1000 1 10 Operating time T s Current multiples to the setting I VI characteristic 2 5 20 0 25 2 5 5 10 20 Dial D 0 5 1 1 5 2 3 3 5 4 Extremely inverse EI T 80 𝐼2 1 𝐷 10 s Very inverse VI T 13 5 𝐼 1 𝐷 10 s ...

Page 11: ...s Current multiples to the setting I NI characteristic 2 5 20 2 5 5 10 20 Dial D 1 1 5 2 3 0 5 0 25 0 01 0 1 1 10 100 1000 1 10 Operating time T s Current multiples to the setting I DT characteristic 2 5 20 2 5 5 10 20 Dial D 1 1 5 2 3 0 5 0 25 3 5 4 6 Normal inverse NI T 0 14 𝐼0 02 1 𝐷 10 s Definite time DT T 2 𝐷 10 s ...

Page 12: ...stics 20 40 60 80 100 120 140 160 180 200 500 450 400 350 300 250 200 150 100 50 0 Current multiples to the setting Operating time ms 20 40 60 80 100 120 140 160 180 200 500 450 400 350 300 250 200 150 100 50 0 20 40 60 80 Sensitivity setting in 3 step characteristic Current multiples to the setting Operating time ms ...

Page 13: ...x 60ms after holding when input current is less than the setting value Setting switches for using condition Don t use any tool with a sharp point when the switches are set It may cause damage to the switch lever SW1 Freque ncy SW2 Inst Step No ON 50Hz ON 3steps OFF 60Hz OFF 2steps SW3 SW4 Inst Sensitivity OFF OFF 20 OFF ON 40 ON OFF 60 ON ON 80 SW5 SW6 Time curve OFF OFF EI OFF ON VI ON OFF NI ON ...

Page 14: ... of larger one among two phases is recorded The relay can save the newest single phenomenon The record is saved in the non volatile memory therefore the record can be read again after shutting the power off Note that the fault record may not be saved if the input current is turned off soon after the relay operation Clearing of fault records Set indicator select switch to CLEAR FAULT REC and hold f...

Page 15: ...it E C1R C2R C2T C1T a2 a1 D T1 T2 52a Pallet switch Auxiliary power supply Current changeover switch Tripping route When a fault occurs the trip contact between and closes then trip coil of CB is energized and make CB trip c No voltage tripping type MOC A3V R S T CB CT Load side TC1 Current changeover switch A No voltage tripping coil To alarm circuit E C1R C2R C2T C1T a2 a1 D T1 T2 Pallet switch...

Page 16: ...onnection This figure shows the connection of current tripping type For voltage tripping type the terminal number should be changed as below T1R T1 T1T T2 C2T2R C2R C2T2T C2T Fig 1 5 Connection example Test A relay test is carried out sufficiently before shipment but at the following cases it is recommended the test should be carried out again a When the products are delivered and unpacked b At th...

Page 17: ... setting Minimum setting 10 of setting value Instantaneous Each setting 15 of setting value Operating time Time lag 300 of setting Minimum setting Characteristic control point of operating time 17 of nominal value 700 of setting 12 of nominal value Instantaneous 200 of setting Minimum setting 50ms or less 5 Example of operation test circuit The circuit examples of the overcurrent relay test equipm...

Page 18: ...1 a2 9 9 9 9 9 9 14 MOC A3V R MOC A3V RD C1R T1R C2 T2R C2 T2T T1T C1T a2 a1 9 5 9 5 9 5 9 5 9 5 9 5 9 5 9 5 9 5 9 5 MOC A3T R Do not connect to the terminals or the relay may not operate properly The terminal is junction terminal for grounding wire if there was grounding wire in the existing relay Fig 1 7 Terminal layout ...

Page 19: ...t may cause electric shock or damage to the circuit Before the subunit is to be drawn out ensure that the following items are checked in order not to carry out the work in hot line condition Lock of the tripping circuit Turning off the main circuit Disconnect CT VT circuit Turning off the auxiliary power supply The CT circuit is equipped with an automatic short circuit piece so that the CT seconda...

Page 20: ...the subunit with your finger hooked on the drawer handle on both sides Support the frame of subunit and pull out 2 Procedure of housing Drawer fixing screw Support the frame of subunit and place the subunit in the case along the rails Insert the subunit into the case horizontally Open the cover and tighten the drawer fixing screw Cover Cover ...

Page 21: ...p the upper side of the cover from the inner surface Then remove from the protrusion of the body Installing the cover As shown in Fig 1 10 mount the holes on the upper side of the cover to the protrusion of the body Then press down lightly on the lower side of the cover and mount to the protrusion of the body in the same way as above When replacing the cover during operation be careful not to touc...

Page 22: ...plied to the protection relay have limited lifetime which will bring the degradation to the relay The degree of degradation will be variable depending on the purpose aging usage environment and unevenness on the performance of each part Our company designs its products so that the recommended renewal period is 15 years or more However there may be some possibilities to occur any failures before re...

Page 23: ...HEAD OFFICE 7 3 MARUNOUCHI 2 CHOME CHIYODA KU TOKYO 100 8310 JAPAN First edition Oct 2020 ...

Reviews: