![Siemens 7SR18 Solkor Скачать руководство пользователя страница 47](http://html.mh-extra.com/html/siemens/7sr18-solkor/7sr18-solkor_manual_383100047.webp)
7SR18 Description Of Operation
Unrestricted Page 44 of 78
©2018 Siemens Protection Devices Limited
3.6
Current Protection: Cold Load (51c)
The setting of each shaped overcurrent element (51-n) can be inhibited and alternative ‘cold load’ settings (51c-n)
can be applied for a period following circuit switch in.
The Cold Load settings are applied after the circuit breaker has been open for longer than the
Pick-Up Time
setting.
Following circuit breaker closure the ‘cold load’ overcurrent settings will revert to those defined in the Phase
Overcurrent menu (51-n) after either elapse of the
Drop-Off Time
setting or when the measured current falls
below the
Reduced Current Level
setting for a time in excess of
Reduced Current Time
setting.
During cold load settings conditions any directional settings applied in the Phase Overcurrent menu are still
applicable.
A CB ‘Don’t Believe It’ (DBI) alarm condition, see Section 4.3, is not acted on, causing the element to remain
operating in accordance with the relevant 51-n settings. Where the
Reduced Current
setting is set to
OFF
reversion to 51-n settings will only occur at the end of the
Drop-Off Time
. If any element is picked up on expiry of
Drop-Off Time
the relay will issue a trip (and lockout if a recloser is present).
If the circuit breaker is re-opened before expiry of the
Drop-Off Time
the drop-off timer is held but not reset.
Resetting the timer for each trip could result in damaging levels of current flowing for a prolonged period during a
rapid sequence of trips/closes.
Cold load trips use the same binary output(s) as the associated 51-n element.
Operation of the cold load element can be inhibited from:
Inhibit Cold Load
A binary or virtual input.
Figure 3.6-1 Logic Diagram: Cold Load Settings (51c)
Содержание 7SR18 Solkor
Страница 1: ...Energy Management 7SR18 Solkor Line Differential Relay Reyrolle Protection Devices ...
Страница 2: ...Siemens Protection Devices Limited 2 ...
Страница 93: ...7SR18 Configuration Guide Unrestricted Page 12 of 12 2015 Siemens Protection Devices Limited ...
Страница 161: ...7SR18 Performance Specification Unrestricted Page 44 of 44 2018 Siemens Protection Devices Limited ...
Страница 179: ...7SR18 Solkor Settings Guide Unrestricted Page 4 of 44 2016 Siemens Protection Devices Limited Typical Menu Structure ...
Страница 221: ...7SR181 Solkor Technical Manual Chapter 4 Page 2 of 80 2016 Siemens Protection Devices Limited ...
Страница 225: ...7SR181 Solkor Technical Manual Chapter 4 Page 6 of 80 2016 Siemens Protection Devices Limited ...
Страница 289: ...7SR181 Solkor Technical Manual Chapter 4 Page 70 of 80 2016 Siemens Protection Devices Limited ...
Страница 291: ...7SR181 Solkor Technical Manual Chapter 4 Page 72 of 80 2016 Siemens Protection Devices Limited ...
Страница 293: ...7SR181 Solkor Technical Manual Chapter 4 Page 74 of 80 2016 Siemens Protection Devices Limited ...
Страница 353: ...7SR18 Commissioning Maintenance Guide Unrestricted Page 54 of 54 2018 Siemens Protection Devices Limited ...