2 Functions
165
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
2.8.2.2
Setting Notes
General
Restart inhibit is only effective and accessible if address
143
48
is set to
Enabled
. If
not required, this function is set to
Disabled
. The function can be turned
ON
or
OFF
under address
4301
FCT 66
..
Note
When function settings of the restart inhibit are changed, the thermal profile of this
function is reset.
The restart inhibit acts on the starting process of a motor that is shut down. A motor is
considered shut down if its current consumption falls below the settable threshold
212
BkrClosed I MIN
. Therefore, this threshold must set lower than the motor idle cur-
rent.
Characteristic
Values
Many of the variables needed to calculate the rotor temperature are supplied by the
motor manufacturer. Among these variables are the starting current
I
STARTUP
, the
nominal motor current
I
MOT. NOM
, the maximum allowable starting time
T START MAX
(address
4303
), the number of allowable starts from cold conditions (n
cold
), and the
number of allowable starts from warm conditions (n
warm
).
The starting current is entered at address
4302
IStart/IMOTnom
, expressed as a
multiple of nominal motor current. In contrast, the nominal motor current is entered as
a secondary value, directly in amperes, at address
4305
I MOTOR NOMINAL
. The
number of warm starts allowed is entered at address
4306
(
MAX.WARM STARTS
) and
the difference (
#COLD-#WARM
) between the number of allowable cold and warm starts
is entered at address
4307
.
For motors without separate ventilation, the reduced cooling at motor stop can be ac-
counted for by entering the factor
K
τ
at STOP
at address
4308
. As soon as the
current no longer exceeds the setting value entered at address
212
BkrClosed I
MIN
, motor standstill is detected and the time constant is increased by the extension
factor configured.
If no difference between the time constants is to be used (e.g. externally-ventilated
motors), then the extension factor
K
τ
at STOP
should be set to 1.
The cooling with the motor running is influenced by the extension factor
4309
K
τ
at
RUNNING
. This factor considers that motor running under load and a stopped motor
do not cool down at the same speed. It becomes effective as soon as the current
exceeds the value set at address
212
BkrClosed I MIN
. With
K
τ
at RUNNING
=
1 the heating and the cooling time constant are the same at operating conditions (
I
>
BkrClosed I MIN
).
Example: Motor with the following data:
Nominal Voltage
V
Nom
= 6600 V
Nominal current
I
Nom
= 126 A
Startup current
I
STARTUP
= 624 A
Startup Duration
T
STARTUP
= 8.5 s
Allowable Starts with Cold Motor
n
cold
= 3
Allowable Starts with Warm Motor
n
warm
= 2
Current Transformer
200 A / 1 A
Содержание siprotec SJ62
Страница 3: ...3 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 9: ...Preface 9 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 21: ...Contents 19 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 35: ...1 Introduction 33 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 365: ...2 Functions 363 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 443: ...3 Mounting and Commissioning 441 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 529: ...4 Technical Data 527 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 699: ...A Appendix 697 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 701: ...Literature 699 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 714: ...Index 712 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...
Страница 715: ...Index 713 SIPROTEC 4 7SJ62 63 64 Handbuch C53000 G1140 C147 A Edition 07 2015 ...