Settings For Start Inhibit Of Motors - Siemens SIPROTEC 7SJ62 Instruction Manual

6.10.2.1 Settings for Start Inhibit of Motors

Addr. LCD-Text
4301 FCT 66
4302 IStart/IMOTnom
4303 T START MAX.
4304 T Equal
7SJ62 Manual
C53000-G1140-C121-1
the difference between the number of allowable cold and warm starts is entered at ad-
dress  &2/'² :$50.
For motors without separate ventilation, the reduced cooling at motor stop can be ac-
counted for by entering the Nτ²)$&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 kτ factor.
If no difference between the time constants is to be used (e.g. externally-ventilated
motors), then the Nτ²)$&725 should be set to .
Example: Motor with the following data:
Nominal Voltage
Nominal Current
Starting Current
Starting Duration @ I
Allowable Starts with Cold Motor
Allowable Starts with Warm Motor
Current Transformer Ratio
The following settings are derived from these data:
624 A
⁄
-------------- -
I I =
START N
126 A
126 A
-------------- -
I = = 0.62 I
N
200 A
The following settings are made:
I /I = 4.9
Start N
I = 0.6 A
N
Warm Starts = 2
Cold Starts – Warm Starts = 1
In the list below, the setting range and default setting value for Address 4305 are for
a device with a nominal current rating I
divide the Setting Options values and Default Setting value by 5. Consider the current
transformer ratios when setting the device with primary values.
Setting Options
OFF
ON
~
3.0 10.0
~
3 120 sec
~
0.0 60.0 min
Start
= 4.95
⋅
NCTsec
= 5 A. For a nominal current rating I
N
Default
Setting
OFF 66 Startup Counter for Motors
4.5 I Start / I Motor nominal
10 sec Maximum Permissible Starting Time
1.0 min Rotor Temperature Equilibrium Time
Functions
V = 6600 V
N
I = 126 A
N
I = 624 A
Start
T = 8.5 s
ANL max
n = 3
cold
n = 2
warm
200 A/1 A
N
Comments
= 1 A,
6-109