Circutor computer MAX 12, Инструкция по эксплуатации

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21 Instruction Manual
computer MAX
IMPORTANT:
If C/K is adjusted too low the system will connect and disconnect steps with a
lower threshold and therefore the number of operations to control the average PF
will be higher.
If C/K is adjusted slightly above the required value (10%) the system will react
with higher threshold values and therefore the number of operations to control the
average PF will be lower. Wear of PF compensation is also lower.
6�1�4�- C/K PARAMETER CALCULATION
For conditions other than those given in
Table 10
the parameter C/K can be calculated as fol-
lows.
The necessary data to perform the calculation are: The power of the smaller capacitor step,
Q and the supply voltage V. Then, the smaller step reactive current, IC, can be calculated as:
V .
Q
C
I
3
=
The current transformer ratio, K :
sec
I
prim
I K / =
where :
prim
I is the CT primary rated current (i.e. in a 250/5 CT , the primary rated current is 250
A)
sec
I is the CT secondary rated current , usually 5 A
the C/K parameter would be:
V . K .
Q
K
I
K / C
C
3
= =
Example:
Assume a PF equipment at 500V where the smaller capacitor is rated to 60kvar and
the CT has a ratio 500/5. The calculation would be as follows:
K ratio:
100 5 / 500 = =
K
Smaller capacitor current :
A I
C
28 , 69
500 . 3
1000 . 60
= =
69 , 0
100
28 , 69
/ = = =
K
Ic
K C
C/K :
A I
C
28 , 69
500 . 3
1000 . 60
= =
69 , 0
100
28 , 69
/ = = =
K
Ic
K C
6�1�5�- STAGE’S CONFIGURATION OF PF CORRECTION EQUIPMENT (CONFIGURA-
TION PROGRAM)
To set-up this parameter, use the keys until the cursor points to the option , then
push
.
During the set-up of this parameter, the screen shows alternatively one of the options T1 to T6
and the cos j .
PF correction equipment is constituted by several capacitor stages, which may have different
power ratings. Taking as base the power of the smaller capacitor stage, the powers of the rest