Siemens siprotec 7SJ63, Инструкция по эксплуатации

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Functions
6-109
7SJ63 Manual
C53000-G1140-C120-1
the difference between the number of allowable cold and warm starts is entered at ad-
dress
&2/'²:$50
.
For motors without separate ventilation, the reduced cooling at motor stop can be ac-
counted for by entering the
N
τ
²)$&725
at address . As soon as the current no
longer exceeds the current flow monitoring setting entered at address , the time
constant is increased by the k
τ
factor.
If no difference between the time constants is to be used (e.g. externally-ventilated
motors), then the
N
τ
²)$&725
should be set to .
Example: Motor with the following data:
Nominal Voltage V
N
= 6600 V
Nominal Current I
N
= 126 A
Starting Current I
Start
= 624 A
Starting Duration @ I
Start
T
ANL max
= 8.5 s
Allowable Starts with Cold Motor n
cold
= 3
Allowable Starts with Warm Motor n
warm
= 2
Current Transformer Ratio 200 A/1 A
The following settings are derived from these data:
The following settings are made:
I
Start
/I
N
= 4.9
I
N
=
0.6 A
Warm Starts =
2
Cold Starts – Warm Starts = 1
6.10.2.1 Settings for Start Inhibit of Motors
In the list below, the setting range and default setting value for Address 4305 are for
a device with a nominal current rating I
N
= 5 A. For a nominal current rating I
N
= 1 A,
divide the Setting Options values and Default Setting value by 5. Consider the current
transformer ratios when setting the device with primary values.
I
START
I
N
⁄
624 A
126 A
---------------
4.95 = =
I
N
126 A
200 A
---------------
0.62 I
N CTsec
⋅
= =
Addr. LCD-Text Setting Options Default
Setting Comments
4301 FCT 66 OFF
ON OFF 66 Startup Counter for Motors
4302 IStart/IMOTnom 3.0
~
10.0 4.5 I Start / I Motor nominal
4303 T START MAX. 3
~
120 sec 10 sec Maximum Permissible Starting Time
4304 T Equal 0.0
~
60.0 min 1.0 min Rotor Temperature Equilibrium Time
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