7-4
MM2 Motor Manager 2
GE Power Management
7.2 FUNCTIONAL TESTS
7 TESTING
7
7.2.2 UNBALANCE EXAMPLES
a) EXAMPLE #1
Find the percentage unbalance given the following information:
We have
I
av
given by:
Since
I
av
< I
fl
, the following formula is used:
Since the unbalance is greater than 15%, an UNBALANCE alarm will occur if this condition persists
for longer than 5 seconds and the AUX Relay 1 will energize.
b) EXAMPLE #2
Find the percentage of unbalance given the following information:
We have
I
av
given by:
Since
I
av
> I
fl
, the following formula is used:
Since unbalance is greater than 30%, a SINGLE PHASE trip will occur if this condition persists for
longer than 5 seconds and the AUX Relay 2 will energize.
VALUE
PRIMARY
SECONDARY (5A)
I
a
73 A
3.65 A
I
b
100 A
5 A
I
c
100 A
5 A
VALUE
PRIMARY
SECONDARY (5A)
I
a
100 A
5 A
I
b
80 A
4 A
I
c
150 A
7.5 A
I
av
I
a
I
b
I
c
+
+
3
-------------------------
73
100
100 A
+
+
3
---------------------------------------------
273
3
----------
A = 91 A
=
=
=
% unbalance
I
n
I
av
–
I
fl
--------------------
100
×
73
91
–
100
----------------------
100
×
18%
=
=
=
I
av
I
a
I
b
I
c
+
+
3
-------------------------
100
80
150 A
+
+
3
---------------------------------------------
330
3
----------
A = 110 A
=
=
=
% unbalance
I
n
I
av
–
I
fl
--------------------
100
×
150
110
–
100
----------------------------
100
×
40 %
=
=
=
Summary of Contents for MOTOR MANAGER 2
Page 2: ......
Page 4: ......
Page 34: ...3 8 MM2 Motor Manager 2 GE Power Management 3 3 THEORY OF OPERATION 3 HARDWARE 3 ...
Page 80: ...5 12 MM2 Motor Manager 2 GE Power Management 5 5 A4 STATISTICS 5 ACTUAL VALUES 5 ...
Page 188: ...9 40 MM2 Motor Manager 2 GE Power Management 9 13 SOFT STARTER 9 STARTER TYPES 9 ...
Page 212: ...E 4 MM2 Motor Manager 2 GE Power Management E 1 CT ISOLATION APPENDIXE E ...
Page 220: ...iv MM2 Motor Manager 2 GE Power Management INDEX ...