mopn motor protection relay

[merajdab]

Hi friends

 

I have to test MOPN 01 motor protection relay from ALSTOM.It monitors current in two phases only and the earth fault current is obtained from a corebalance ct or residually connected cts.

 

 

 

Here I have detailed my problems and the text is slightly long , but I would appreciate if u could pls take some time and read it to help me out. I thank all of those who chose to open it and read it. Thank u in advance.

 

 

My problem is that I do not have a current injection set that could give me two currents at a phase angle of 120 deg or a phase shifter that I could use for the purpose.

I have only one single phase current injection set. Hence I am confused about simulating the conditions for test with a single phase unit. Moreover I have never tested this relay before , so I request someone with deeper knowledge to please look at it and give comments.

 

CONSIDER THE FOLLOWING DATA

 

I thermal .88 In

Te1 9 minutes

Te2 Te2=Te1

Tr(cooling time constant) 45 minutes

E1(start inhibit threshold- % of thermal capacity) 40% -motor once stopped will not restart until the thermal capacity is above this value

E1(start inhibit threshold-% of thermal capacity) 90% - relay will give alarm when this amount of thermal capacity is spent

Ph Isc- Ph short circuit protection ( provided for protection against shortcircuit at the motor terminals) 1.2 starting current

Io ( earth fault setting ) .4 In

I2 (Negative sequence setting ) .2 In

Is ( starting current threshold) 3*I thermal

Tb (Starting time) 6.0 seconds

Tb1(Time to trip on stall ) 1.6 seconds

 

 

 

I have decided to test the relay in the following manner and I request you to kindly check if there is a problem

 

1. To check the earth fault unit

Inject a single phase current equal to earth fault setting in the designated terminals and verify that the trip occurs after the set time delay

2. To check the short circuit current threshold Isc

Inject a current equal to 1.2 times starting current in any one of the phase monitoring units of the relay and verify that the relay picks up after 100ms(given fixed value by the manufacturer)

Or

Inject 1.2*starting current into both of the phase monitoring units connected in series and verify the trip as said above

3. To check the negative sequence unit

Inject 0.2In into any one phase monitoring unit and the relay should pick up after a fixed time delay (if any).

4. To check the cold thermal curve

Select a value of the current from the cold curve and inject a single phase current in both the phase monitoring units connected in series and verify the time from the curve.- to be done for at least three values.

5. To check the thermal threshold E1

Here I do not know , how much current I should inject in the phase monitoring units of the relay. I should ideally spend 50% of the thermal capacity and verify that the relay does not allow me to restart unless the remaining thermal capacity is 60%.

6. To check the thermal threshold E2

The problem here is similar to the problem mentioned for E1

7. Startup threshold Is.

Inject a current equal to the startup threshold through both the phase monitoring units of the relay connected in series. The relay should pickup after the startup time elapses ( 6 seconds in this case)

8 Rotor stall delay

Inject a current greater than the startup threshold through both the phase monitoring units of the relay connected in series. The relay should pick up after the fixed time delay of 1.6 seconds.

 

Thank u all once again.

 

isoA120

[Guest]

hi friends

i have a mopn 01 motor protection relay from alstom

i need technical manual for this relay

you can mail to me to mahde173@yahoo.com

 

thank u all once again