Breaker classification and characteristics

Promulgator : TAIXIDate : 2018-05-08Views : 440

Circuit breaker can be divided into:
3.1 Classification by type of use: A or B (see 4.4).
3.2 According to breaking media points, for example:
- air separation;
- Breaking of the vacuum;
— Gas separation.
3.3 According to the design type, for example:
— open type;
- Plastic shell type."
3.4 According to the operating mechanism's control method, namely:
— related to human operation;
- no human operation,
- relevant power operation;
— Unrelated to power operation;
— Storage operation.
3.5 Is it suitable to isolate points:
- Suitable for isolation;
— Not suitable for isolation.
3.6 According to the need for maintenance points:
- need to repair;
— No need for repairs.
3.7 According to the installation method, for example:
- fixed type;
— Plug-in type,
— Drawer type.
3.8 According to shell protection grade points (see GB/T 14048.1-2000 7.11).
4 Characteristics of circuit breakers
4.1 Features Overview
The characteristics of the circuit breaker must be indicated by the following items (if applicable):
- type of circuit breaker (4-2);
- Ratings and limits of the main circuit (4.3);
- Use categories (4.4);
- Control circuit;
- Auxiliary circuits (4.6);
— Release type (4.7);
- What type of fuse (with a fuse breaker) (4.8);
— Operating overvoltage (4.9).
4.2 Types of circuit breaker
The following items should be specified:
4.2.1 Number of poles
4.2.2 Current Type
1) Also known as molded shell or plastic shell type.
Adopt instructions:
11 is "open type" in IEC 60947-2.


Characteristics of circuit breakers
4.1 Features Overview
The characteristics of the circuit breaker must be indicated by the following items (if applicable):
- type of circuit breaker (4-2);
- Ratings and limits of the main circuit (4.3);
- Use categories (4.4);
- Control circuit;
- Auxiliary circuits ((4.6);
— Release type (4.7);
- What type of fuse (with a fuse breaker) (4.8);
— Operating overvoltage (4.9).
4.2 Types of circuit breakers
The following items should be specified:
4.2.1 Number of poles
4.2.2 Current Type
1) Also known as molded shell or plastic shell type.
Adopt instructions:
11 is "open type" in IEC 60947-2.
Current type (AC or DC), number of phases and nominal frequency at AC.
4.3 Ratings and Limits of the Main Circuit
The rating of the circuit breaker shall be as specified in 4.3.1-4.4, but not all of the listed ratings are necessarily specified.
4.3.1 Rated voltage
Circuit breakers have the following rated voltages:
4.3.1.1 Rated Operating Voltage (U,)
4.3.1.1 of GB/T 14048.1-2000 applies and is supplemented as follows:
– For circuit breakers referred to in a) of Note 2 of 4.3.1.1 of GB/T.1 4048.1-2000: U. Generally represents the voltage between phases.
Note
1 For a three-phase four-wire neutral grounding system, it refers to the phase-to-ground voltage, including the phase-to-phase voltage (for example, 277/480V).
2 For a three-phase three-wire ungrounded or impedance grounded system, which represents the phase-to-phase voltage (for example, 480V),
Circuit breakers for ungrounded or impedance grounded systems (IT) require additional testing in accordance with Annex H.
— For circuit breakers referred to in b) of Note 2 of 4.3.1.1 of GB/T 14048.1-2000:
These circuit breakers require additional tests in accordance with Appendix C.
U. Should indicate phase (in front of the letter C) voltage.
4.3.1.2 Rated Insulation Voltage (U,)
4.3.1.2 applies in GB/T 14048.1-2000.
4.3.1.3 rated impact withstand voltage (U-,)
4.3.1.3 applies in GB/T 14048.1-2000.
4.3.2 Current
Circuit breakers specify the following currents:
4.32.1 Free Air Heating Current (Ic6)
4.3.2.1 applies in GB / T 14048.1-2000.
4.3.2.2 Agreed closed thermal current ((Ithe)
4.3.2.2 of GB/T 14048.1-2000 is applicable.
4.3-2.3 Rated Current (In)
For a circuit breaker, the rated current is the rated uninterrupted current (I. See GB/T 14048.1-2000, 4.3.2.4), and etc.
In agreement with free air heating current (Ieh) e
4.3.2.4 Current Rating of Four-pole Circuit Breakers
The application of 7.1.8 in GB/T 14048.1-2000.
4.3.3 Rated frequency
4.3.3 applies to GB/T 1 4048.1-2000.
4.3.4 Rated working system
There are the following types of rated work systems as standards:
4.3.4.1 Eight Hours Work
4.3.4.1 applies in GB / T 14048.1-2000.
4.3.4.2 Uninterrupted working system
4.3-4.2 of GB/T 14048.1-2000 is applicable.
4.3.5 Short-circuit characteristics
4.3.5.1 rated short circuit capability (I.. rated short circuit capability of the circuit breaker is specified in the manufacturer's rated operating voltage, rated frequency and a certain power factor (for
The value of the short circuit switch-on capability of the circuit breaker under AC) or time constant (for DC) is expressed in terms of the maximum expected peak current.
4.4 Use category
The category of use of circuit breakers is defined by whether or not the circuit breaker is specifically designated as a series circuit on the load side to achieve selective protection by artificial delay in the event of a short circuit.
4.4 Use category
The category of use of circuit breakers is defined by whether or not the circuit breaker is specifically designated as a series circuit on the load side to achieve selective protection by artificial delay in the event of a short circuit.
4.5 Control Circuits
4.5.1 Electrical Control Circuit
The application of 4.5.1 in GB/T 1 4048.1-2000 applies and is supplemented as follows:
If the rated control power supply voltage is different from the main circuit voltage, it is recommended to use it in Table 5.
4.5.2 Pneumatic Control Circuit (Pneumatic or Electronically Controlled Pneumatic)
4.5.2 applies in GB / T 14048.1-2000.
4.6 Auxiliary Circuits
GB / T 14048.1-2000 4. Applicable.
4. Release device
4.7.1 Type
1) Shunt trip unit.
2) Overcurrent release;
a) instantaneous;
b) The time limit;
Each one has nothing to do with the original load;
- Relevant to the original load (eg thermal release).
Note
1 The term "overload release" is customarily the same as an overcurrent release for overload protection (see 2.4.30 of IEC 60384-1). The term "short circuit
The tripping device" is customarily the same as the overcurrent release for short-circuit protection (see 2.1 1).
2. The term "adjustable release" as used in this standard also includes a replaceable release.
3) Undervoltage release (for disconnection);
4) Other release.
4.7.2 Features
1) Shunt trip unit and undervoltage trip unit (for disconnection):
— rated control circuit voltage (UO;
One current type.
— Rated frequency (refers to AC).
2) Overcurrent release:
— Rated current ((I?) ;
— current types;
- Rated frequency (refers to AC);
- current setting (or setting range);
— The time setting (or the range of the setting).
The rated current of the over-current release means that the current value corresponding to the setting value of the maximum current can be carried under the test conditions specified in 8.3.2.5 (if it is AC, it is a valid value). Under this condition, the temperature rise does not exceed the table The specified value in 7.
4.7.3 Current setting of overcurrent release
For note 2) of circuit-breakers with adjustable release (see 4.7.12), the current setting (or range of current setting, optional)
Used) should be marked on the release or marked on the scale board. The mark can be directly marked on the trip unit in amperage or multiples of the current value.
For circuit breakers fitted with non-adjustable releases, the markings may be marked on the circuit breaker. If the operating characteristics of the overload release comply with the requirements of Table 6, it is sufficient to indicate its rated current (I.) on the circuit breaker.
In the case of a tripping device that is actuated indirectly by a current Transformer, the marking may indicate the primary current or target of the supplied current transformer.
The current setting value of the over-load release. No matter how marked, it should explain the transformation ratio of current transformer.
Unless otherwise specified:
- The operating value of the over-current release, except for the thermal type, means that there is no relationship between the temperature of the ambient air and the ambient temperature at a temperature of 10 to 40 °C at 5 °C;
— For thermal releases, the specified operating value is the reference temperature of +30°C ± 21C. The manufacturer shall specify the effect of changes in ambient air temperature (see item 7.2.1.2.4 2)).
4.7.4 Trip time setting of over-current release
1) Definite time limit over-current release
The delay of this release does not depend on the overcurrent. If the delay time is not adjustable, the tripping time setting value shall be expressed in units of seconds (s) with the opening time of the circuit breaker. If the delay time is adjustable, the tripping time setting value shall be broken. The maximum and minimum values ​​of open time are indicated.
2) Inverse time overcurrent release
The delay of this release depends on the overcurrent. The time-current characteristics should be given in the form of a curve provided by the manufacturer. These curves should show the relationship between the disconnection time from the cold state and the current change within the tripper motion range. The manufacturer shall specify the tolerances for using these curves in a suitable manner.
Both of these curves should give the maximum and minimum current setting values. If the time setting of the given current setting value is adjustable, it is recommended that each of these curves should also give each maximum and minimum time setting value.
Note: The proposed current is represented by the abscissa and the time is represented by the ordinate. Both coordinate axes are logarithmic. In addition, in order to facilitate the study of the cooperation of various types of over-current protection devices, it is recommended that the current be expressed in multiples of the setting current in accordance with the standard drawings detailed in 5.6.4 of GB 13539.1--1992 and the provisions in GB 13539.2-1992. s said.
4.8 Built-in fuses (circuit breakers with fuses)
GB / T 14048.1-2000 4.8 applies.
The manufacturer should provide the required information.
4.9 Operating Overvoltage
When the rated impact withstand voltage UImn has been declared, then 4.9 of GB/T 1 4048.1-2000 applies.