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Q: What is meant by reverse CT connections ?
A: CT is said to be connected in reverse direction if
1. either P1 is facing towards load.
2. S2 (CT red Wire) is connected to the terminal
with rectangle.
Q: What if CT is connected in reverse direction?
A: If CT of a particular phase connected in reverse
direction, then
if load type is Active: Watt of that phase start showing
negative
if load type is Reactive: VAR power sign of that phase
get reverse.
if load type is Apparent: No Effect.
Q: Will reverse CT effect the total power and Energy?
A: No. Meter will internally correct the CT, if it is connected
in wrong direction. Total power and Energy will remains
unaffected.
Q: How meter notify the site engineer about CT direction ?
A: Meter reflect CT direction under diagnosis parameter.
following conditions must meet for meter to correctly
calculate CT direction
1. Current must be grater than 10mA (0.010A).
2. If voltage is connected in phase sequence R, Y & B
then, current should also be in R, Y & B sequence.
sample screen shown below.
Reasons for Voltage not present:
a.) Loose connections
b.) Wire break.
c.) Phase missing from the source.
d.) Fuse connected at input voltage might got blown off.
LCD
Series
ENERSOL
MFLR09
PROG
COM
V RV: No
YV: Yes BV:Yes
Input voltage connection is at terminal
10, 11 & 12 (13 for neutral).
if voltage present only at Y and B
terminal, than display will be shown
like this.
Sample Display read as
R Voltage - No connected
Y Voltage - Connected & greater than
25 VLN.
B Voltage - Connected & greater than
25 VLN.
Sample Screen reads as
Row 1: No current (or less than
10mA) current is flowing via
CT of R Phase
Row 2: Y phase CT installed in
correct direction,
B Phase CT is installed in
reverse direction.
1 2
3
4
5 6 7
8 9
10 11 12 13 14 15 16 17 18
Voltage inputs 80 = 480VAC LL
Current Input: 50mA to 60A
Ph N
Aux. Sup.
90-300V, 2VA
RS485
DANGER
Turn off power before working
R CT
Y CT
B CT
RS485
V1 V2 V3 Vn
+
-
1 2
3
R CT
CT Black wire
indication.
LCD
Series
ENERSOL
MFLR09
PROG
COM
I rCT: NL
yCT:CR bCT: RE
