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EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R 31/00, G08B; locating faults along lines G01R 31/08; emergency protective devices H01H)
Definition statement
This subclass/group covers:

Emergency electric circuit arrangements for the automatic protection of electric equipment used for generation, conversion, transmission or distribution of electric power in the event of an abnormal operating condition.

Thus the scope of this subclass is limited to protective circuits for the protection of power systems for: generating electric power (alternators, generators), converting electric power (power convertors in HVDC links, power motors for industrial applications, power transformers), transmission of electric power (High Voltage AC or HVDC lines or cables) or distribution of electric power (Medium voltage lines, cables and distribution switchgear and Low Voltage lines, cables and switchgear up to the sockets of secondary customers)

In this subclass, the protective circuit arrangements are classified :

A. according to the measures taken:

  • Automatic disconnection by means of any type of switch (circuit-breaker, disconnector, interrupter, fuse or static switches) directly responsive to an undesired change from normal electric or non-electric operating conditions with or without subsequent reconnection.
  • Limiting excess current or voltage without disconnection.
  • Preventing the switching-on in case an undesired working condition might result.

B. or/and by the device being protected, e.g. transformer, motor...

C. or/and by the model used to simulate the device

D. by details of one of the above, e.g. detection means

Relationship between large subject matter areas
Boards, substations, or switching arrangements
Installation of electrical cables or lines
Circuit arrangements for supplying or distributing electric power
Dynamo-electric machines
Electric converters
Other electric machines
Control or regulation of motors, generators
References relevant to classification in this subclass
This subclass/group does not cover:
Protection involving charging/discharging batteries:
Structural association of protection devices with motors or generators
Protecting converters by control
Protecting electric motors (e.g. providing protection against - overload) by control

Examples of places where the subject matter of this subclass is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Vehicles
Electrically propelled vehicles
Aircrafts
Household appliances
Computers
Regulators
Circuit arrangements only comprising a combination of mechanical switches, static switches and overvoltage limiting devices for the purpose of special switching applications, e.g. DC
Electronic switching
Amplifiers
Informative references
Attention is drawn to the following places, which may be of interest for search:
Electric devices on electrically-propelled vehicles for safety purposes
Electric circuits specially adapted for vehicles
Safety devices in conjunction with control or operation of a machine
Arrangements for testing electrical properties; arrangements for locating electric faults; arrangements for electric testing characterized by what is being tested
Electrical safety arrangements for controlling or regulating in general
Constructive details of emergency protective devices
Emergency protective devices
Modifications for protecting electronic switching circuits
Special rules of classification within this subclass

Subgroups and head group:

If the subject-matter of a document relates to a protective circuit having different functionalities for each of which a sub-group exists, then the document is to be classified in the head-group unless a sub-group exists for this particular combination of functionalities (e.g. H02H 3/10, H02H 3/207).

Details of emergency protective circuit arrangements
Definition statement
This subclass/group covers:

All details of emergency protective circuit arrangements covering the detection means, the connection of the detection means, the transmission of signals, the data processing means, the arrangements for preventing response to transient abnormal conditions and the arrangements for supplying operative power to the circuit arrangements (e.g monitoring of power supply for trip energy, backup supply, avoid failure due to high voltage testing).

Informative references
Attention is drawn to the following places, which may be of interest for search:
Detection means per se
G01, e.g. G01R
Means for detecting the presence of an arc structurally associated with emergency protective devices: for switches in generalfor HV circuit breakers
Means for detecting or reacting to mechanical or electrical defects (structurally associated with Gas-insulated switchgear)
Special rules of classification within this group

As this group concerns details of emergency protective circuits, it is normally combined with a group symbol or an Indexing Code the aspect it is a detail of. Example: WO 2009123615 (Hewlett Packard Development company) is classified in H02H 1/0007 and in H02H 3/087. In exceptional cases is inventive information classified here only.

Arrangements for supplying operative power { (power supply arrangements in general G05F, H02M) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Power supply arrangements in general
Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection (specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable of line systems H02H 7/00; systems for change-over to standby supply H02J 9/00) {integrated protection (for motors H02H 7/0822) }
Definition statement
This subclass/group covers:

This group is subdivided according to the electric parameter it is responsive to (e.g. overcurrent, overvoltage) and comprises all kinds of protective circuits comprising detection means for the detection of electrical variables of the power equipment to be protected (e.g. current transformers or sensors, voltage transformers or sensors), analog or digital circuits for converting, analysing or comparing the detected electrical values with pre-determined threshold levels and initiating a tripping signal to a disconnecting device to automatically disconnect the equipment to be protected from the power source to avoid or to limit damages to the equipment. These circuits may also be provided with reclosing features.

.Various types of protection are covered: overcurrent, overvoltage, undervoltage, earth fault, differential protection, distance protection, phase loss, unbalance...

References relevant to classification in this group
This subclass/group does not cover:
Specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems
Systems for change-over to standby supply
Load shedding, e.g. maintaining supply
Informative references
Attention is drawn to the following places, which may be of interest for search:
Testing of protective devices, e.g. with a separate device
Protective switch with testing means
Special rules of classification within this group
  • Protective circuits protecting against the effects of geomagnetic induced current (GIC) are classified in the head group H02H 3/00
  • Protective circuits responsive to more than two electric variables or to electric variables not covered by the subgroups are classified in H02H 3/00.
with automatic disconnection after a predetermined time (H02H 3/033, H02H 3/06 take precedence; {timing in overcurrent protection circuits H02H 3/093; in undervoltage protection circuits H02H 3/247; staggered disconnection H02H 7/30} )
References relevant to classification in this group
This subclass/group does not cover:
Several disconnections in a preferential order
Automatic reconnection
Informative references
Attention is drawn to the following places, which may be of interest for search:
Timing in overcurrent protection circuits
Timing in undervoltage protection circuits
Staggered disconnection
with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned { (watching of pilot wires H02H 1/0084; protection of protective arrangements H02H 7/008; indication of the state of electronic switches H03K 17/18) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Watching of pilot wires
Protection of protective arrangements
Indication of the state of electronic switches
with means for increasing reliability, e.g. redundancy arrangements { (for logic circuits H03K 19/003) }
References relevant to classification in this group
This subclass/group does not cover:
Logic circuits
responsive to excess current (responsive to abnormal temperature caused by excess current H02H 5/04)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Responsive to abnormal temperature caused by excess current
with timing means { (in general H02H 3/027; thermal delay H02H 3/085; timing means for undervoltage protection H02H 3/247) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Timing means in general
Thermal delay
Timing means for undervoltage protection
responsive to underload or no-load { (for motors H02H 7/0827) }
References relevant to classification in this group
This subclass/group does not cover:
Responsive to underload or no-load for motors
responsive to occurrence of voltage on parts normally at earth potential { (monitoring earth connection H02H 5/105) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Monitoring earth connection
responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H 3/26; {monitoring earth connection H02H 5/105} )
References relevant to classification in this group
This subclass/group does not cover:
Balanced or differential arrangement
Informative references
Attention is drawn to the following places, which may be of interest for search:
Monitoring earth connection
by means of an auxiliary voltage injected into the installation to be protected { (using summation current transformers H02H 3/33) }
References relevant to classification in this group
This subclass/group does not cover:
Using summation current transformers
responsive to undervoltage or no-voltage { (H02H 3/207 takes precedence) }
References relevant to classification in this group
This subclass/group does not cover:
Responsive to under-voltage
involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus { (for transformers H02H 7/045) }
References relevant to classification in this group
This subclass/group does not cover:
Transformers
using summation current transformers (H02H 3/347 takes precedence)
References relevant to classification in this group
This subclass/group does not cover:
Three-phase systems using summation current transformers
Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal non-electric working conditions with or without subsequent reconnection (using simulators of the apparatus being protected H02H 6/00; specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems H02H 7/00)
Definition statement
This subclass/group covers:

This group is subdivided according to the non-electric parameter it is responsive to (e.g. temperature, fluid pressure) and comprises all kinds of protective circuits comprising detection means for the detection of non-electrical variables of the power equipment to be protected (e.g. temperature sensor, fluid pressure sensor, sensor to detect mechanical injury), analogue or digital circuits for converting, analysing or comparing the detected electrical values with pre-determined threshold levels and initiating a tripping signal to a disconnecting device to automatically disconnect the equipment to be protected from the power source to avoid or to limit damages to the equipment or to protect living beings. These circuits may also be provided with reclosing features

References relevant to classification in this group
This subclass/group does not cover:
Emergency protective circuit arrangements responsive to undesired changes from normal non-electric working conditions using simulators of the apparatus being protected, e. g. thermal images
Specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems
Smoke alarm power shut-off devices (if disconnection is a prevention measure)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Radiation detectors
Nuclear explosion detection
Moisture alarm
G08B21/00B1
Temperature detectors
responsive to abnormal temperature {specially adapted for electric machines H02H 7/0852}
References relevant to classification in this group
This subclass/group does not cover:
Circuits specially adapted for electric machines
Emergency protective circuit arrangements responsive to undesired changes from normal non-electric working conditions using simulators of the apparatus being protected, e.g. using thermal images
Definition statement
This subclass/group covers:

Protective circuits comprising simulation or modelling means for the determination of non-electrical variables of the power equipment to be protected (e.g. temperature), and comparing the simulated non-electric variables with pre-determined threshold levels and initiating a tripping signal to a disconnecting device to automatically disconnect the equipment to be protected from the power source to avoid or to limit damages to the equipment or to protect living beings. These circuits may also be provided with reclosing features.

Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions (structural association of protective devices with specific machines or apparatus and their protection without automatic disconnection, see the relevant subclass for the machine or apparatus)
Definition statement
This subclass/group covers:

Emergency protective circuit arrangements specially adapted for protecting specific types of electric machines or apparatus (e.g. transformers, electric motors) and effecting automatic switching in the event of an undesired change from normal electric or non-electric working conditions.

This group covers also emergency protective circuit arrangements for sectionalised protection of cable or line systems, e.g. for disconnecting a section on which short-circuit. earth fault, or arc discharge has occurred. The objectives of these type of protective circuits is to keep the power system stable and/or to minimize an outage to the greatest extend possible when abnormal electrical conditions occur (e.g. through protective device coordination).

References relevant to classification in this group
This subclass/group does not cover:
Structural association of protective devices with specific machines or apparatus and their protection without automatic disconnection e.g. by control
see the relevant subclass for the machine or the apparatus e.g. H02M, H02K, H02PH02J
Informative references
Attention is drawn to the following places, which may be of interest for search:
Structurally associated protection of superconducting magnets or coils in case of quenching
Structural association of measuring or protecting means in transformers
Special means for preventing or reducing unwanted electric or magnetic effects in transformers or coils
Structurally associated protection in motors or generators
Measuring of mechanical vibrations
Monitoring dynamo-electrical machines in operation
Means providing protection of motors against overload without automatic disconnection
Safety arrangements for control or regulation in general
Power operated mechanism for wings
Means for protecting converters other than disconnection
Safety devices for circuit arrangements for charging or depolarizing batteries
Batteries in electrical vehicles
Circuit arrangements for solar cells for maintenance or in case of fire
HVDC Links
Locating faults in cables
against excessive load { (H02H 6/00 takes precedence) }
References relevant to classification in this group
This subclass/group does not cover:
Emergency protective circuit arrangements responsive to undesired changes from normal non-electric working conditions using simulators of the apparatus being protected
{for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal}
Definition statement
This subclass/group covers:

Anti-pinching systems for car-window motors

{characterised by the protection measure taken}
References relevant to classification in this group
This subclass/group does not cover:
Providing protection against overload without automatic interruption of supply (for electric motors or generators)
against increase beyond, or decrease below, a predetermined level of rotational speed (centrifugal switches H01H 35/10)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Centrifugal switches
for converters; for rectifiers { (forming part of the control circuit of the converter, see the relevant group in H02M) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements forming part of the control circuit of the converter,
for static converters or rectifiers { (for discharge lamp power supplies using static converters H05B 41/2851, H05B 41/2921, H05B 41/2981) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Discharge lamp power supplies using static converters
for capacitors (for synchronous capacitors H02H 7/06)
References relevant to classification in this group
This subclass/group does not cover:
Synchronous capacitors
for electronic equipment (for converters H02H 7/10; for electric measuring instruments G01R 1/36; for dc voltage or current semiconductor regulators G05F 1/569; for amplifiers H03F 1/52; for electronic switching circuits H03K 17/08)
Definition statement
This subclass/group covers:

Circuit arrangements responsive to, e.g. overcurrent, overvoltage, arc fault , for protecting solar cells used for power distribution or generation and effecting automatic protection of the solar cells array.

References relevant to classification in this group
This subclass/group does not cover:
Emergency protective circuit arrangements for converters
Emergency protective circuit arrangements for electric measuring instruments
Emergency protective circuit arrangements for dc voltage or current semiconductor regulators
Protective circuit arrangements for solar cells, e.g. effecting disconnecting upon fire or for maintenance, protection of personal, or those structurally integrated in the solar cells, e.g. by-passing diodes or switches
Emergency protective circuit arrangements for amplifiers
Emergency protective circuit arrangements for electronic switching circuits
Informative references
Attention is drawn to the following places, which may be of interest for search:
Generation of electric power by conversion of infra-red radiation, visible light or ultraviolet light, e.g. using photovoltaic [PV] modules
for distribution gear, e.g. bus-bar systems; for switching devices { (detecting mechanical or electrical defects in gas-insulated switchgears H02B 13/065) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Detecting mechanical or electrical defects in gas-insulated switchgears
Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured (locating faults in cables G01R 31/08)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Locating faults in cables
staggered disconnection
Definition statement
This subclass/group covers:

all aspects of circuit arrangements regarding the device coordination in an electrical network with multiple layers in a hierarchical structure and back-up protection.

Emergency protective circuit arrangements for limiting excess current or voltage without disconnection (structural association of protective devices with specific machines or apparatus, see the relevant subclass for the machine or apparatus)
Definition statement
This subclass/group covers:

All types of protective circuit arrangements for protecting power systems, machines and apparatus covered by this subclass against the damaging effects of excess current or voltage without disconnection by limiting the speed of change of electric quantities, avoiding undesired transient conditions (e.g. with filters), by providing intrinsically safe conditions (limiting both voltage and current), by limiting excess current, by limiting excess voltage, or by limiting or suppressing of earth fault currents.

References relevant to classification in this group
This subclass/group does not cover:
Structural association of protective devices with specific machines or apparatus
see the relevant subclass of the machine or the apparatus H02M, H02K, H02PH02J
Informative references
Attention is drawn to the following places, which may be of interest for search:
Superconductive current limiter (resistive type) superconductive current limiter (inductive type)
H01L 39/16, H01F/00
Circuit arrangements for protecting logic circuits
Circuit arrangements for protecting electronic switches
Negative voltage protection in plug-in devices for data transfer (e.g. USB stick hot plugging)
Electrostatic discharge (ESD) protection of Integrated Circuits when aspect of structural integration is important
Protection of semiconductor devices against overvoltage by layout
Soft switching on or off of converters
Protective switch operated by excess voltage, e.g. for lightning protection
Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:
ESD
Electrostatic discharge
responsive to excess current { (current limitation for voltage regulators G05F 1/573; disconnection after limiting H02H 3/025) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Current limitation for voltage regulators
Disconnection after limiting
responsive to excess voltage (lightning arrestors H01C 7/12, H01C 8/04, H01G 9/18, H01T)
Definition statement
This subclass/group covers:
  • Lightning protection in general
  • Avoiding failure due to high voltage testing.
Informative references
Attention is drawn to the following places, which may be of interest for search:
Lightning arrestors
{using a short-circuiting device}
Definition statement
This subclass/group covers:

Crowbars

{responsive to excess voltage appearing at terminals of integrated circuits (protection by specific structural integration design H01L 27/0248) }
Definition statement
This subclass/group covers:

Overvoltage protection circuits, where the integrated circuits can be considered as a black box

Informative references
Attention is drawn to the following places, which may be of interest for search:
Protection by specific structural integration design
Emergency protective circuit arrangements for preventing the switching-on in case an undesired electric working condition might result
Definition statement
This subclass/group covers:

e.g. in case of incorrect or interrupted earth connection, in case of inverted polarity or connection, in case of incorrect phase sequence, in case of too high or too low isolation resistance, too high load, short-circuit or earth fault, in case of too high or too low voltage, or preventing unsafe switching conditions.

Special rules of classification within this group

Protective circuits for preventing connection of outlets to power source if no load and detection of human body should be classified in H02H 5/12 and an Indexing Code given in H01H 11/00.

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Last Modified: 10/11/2013