GB/T 13002-2022 English PDF (GBT13002-2022)

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GB/T 13002-2022: Rotating electrical machines - Thermal protection
GB/T 13002-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 29.160.10
CCS K 20
GB/T 13002-2022 / IEC 60034-11:2020
Replacing GB/T 13002-2008
Rotating electrical machines - Thermal protection
(IEC 60034-11:2020, Rotating electrical machines - Part 11: Thermal protection, IDT)
ISSUED ON: JULY 11, 2022
IMPLEMENTED ON: FEBRUARY 01, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
Introduction ... 5 
1 Scope ... 6 
2 Normative references ... 6 
3 Terms and definitions... 7 
4 Thermal protection limits ... 8 
5 Protection against thermal overload with slow variation ... 9 
6 Protection against thermal overload with fast variation ... 11 
7 Restart after tripping ... 14 
8 Type test ... 14 
9 Routine test ... 15 
References ... 16 
Rotating electrical machines - Thermal protection
1 Scope
This document specifies the requirements for the use of thermal protectors or thermal
detectors, which are installed inside the stator windings of induction motors OR placed
in other suitable locations for induction motors, to prevent serious damage to the
electrical machine, due to thermal overload.
This document applies to 50 Hz or 60 Hz single-speed three-phase cage induction
motors, in accordance with IEC 60034-1 and IEC 60034-12:
a) The rated voltage does not exceed 1000 V;
b) Used as full voltage start or star-delta start.
This document does not apply to:
a) Direct protection of the rotor winding; It is limited to the protection method of
indirect protection of the rotor winding; for large motors (especially 2-pole
motors) and load motors with large starting inertia, special attention shall be paid
to rotor heating, during startup and after "tripping".
b) Protection of bearings and other structural parts.
c) Application-specific protection methods.
Note 1: Although the temperature limits, which are given in this document, are higher than
those specified in IEC 60034-1, the two are not contradictory.
Note 2: There may be additional requirements for special purpose motors, such as household
appliances or motors, which are used in explosive gas atmospheres.
2 Normative references
The contents of the following documents constitute essential provisions of this
document through normative references in the text. Among them, for dated references,
only the version corresponding to the date applies to this document; for undated
references, the latest version (including all amendments) is applicable to this document.
GB/T 755-2019 Rotating electrical machines - Rating and performance (IEC 60034-
1:2017, IDT)
GB/T 21210-2016 Starting performance of single-speed three-phase cage induction
motors (IEC 60034-12:2016, IDT)
3 Terms and definitions
The following terms and definitions apply to this document.
ISO and IEC maintain terminology databases for standardization at:
IEC Electropedia: http://www.electropedia.org/
ISO Online Browsing Platform: http://www.iso.org/obp
3.1
Thermal protection
It is used to protect the windings of rotating electrical machines from thermal
overload or cooling system failure and cause excessive temperature.
3.2
Thermal protection system
A protection system, that protects the windings of rotating electrical machines from
thermal overloading or cooling system failures resulting in overheating, by means
of thermal protectors or thermal detectors.
3.3
Thermal detector
Electrical insulating devices, that are only sensitive to temperature; it can play a
switching function in the protection system, when the temperature reaches a preset
value.
3.4
Thermal protector
The electrical insulating device, which is sensitive to the temperature of the current-
carrying electrical machine winding; it can directly disconnect the power supply of
the electrical machine, when the temperature reaches a preset value.
NOTE: Some thermal protectors are sensitive to temperature and current; a combination of
the two effects triggers a switch in the system, causing it to cut off power.
3.5
5 Protection against thermal overload with slow variation
When encountering thermal overload with slow variation, which is caused by thermal
overload or violation of electrical machine operating procedures, the protection system
will act, to prevent the electrical machine's winding temperature from rising AND make
it not exceed the value in Table 1.
Figures 1 and 2 give examples of temperature, as a function of time, to change with
time.
The determination of the winding temperature shall meet the requirements of the
resistance method, which is specified in 8.6.2 of GB/T 755-2019.
Note 1: If the electrical machine runs for a long time under the limits, which are specified in
Table 1, the limit of insulation winding temperature will exceed the thermal grading, to which
it belongs, which will lead to a shortened life of the electrical machine.
Note 2: The maximum temperature is determined empirically. The thermal overload with slow
variation can be caused by:
● Failure of ventilation or ventilation system, due to excessive accumulation of dust on the
ventilation pipe, or adhesion of dirt on components such as windings or cooling ribs of the
frame;
● The ambient temperature or the temperature of the cooling medium is too high;
● The slowly increasing mechanical overload;
● The electrical machine voltage is under-voltage, over-voltage or unbalanced for a long time;
● The intermittent duty electrical machine runs in violation of its specified working mode;
● Frequency deviation.
3 - Normal periodic work;
4 - Time when the thermal overload with slow variation starts;
X - Time coordinate;
Y - Temperature coordinate.
Figure 2 -- Example of thermal overload with slow variation and direct thermal
protection caused by transition of intermittent duty cycle (S4) including starting
6 Protection against thermal overload with fast variation
When the electrical machine encounters a thermal overload with fast variation, the
thermal protection system will act, to prevent the electrical machine winding
temperature from exceeding the value in Table 2.
Overcurrent relays do not provide protection against repeated fast-changing thermal
overloads, so thermal protection devices shall be considered.
Figures 3 and 4 give examples of temperature, as a function of time, to change with
time.
The method for determining the winding temperature shall comply with the direct
measurement method, which is specified in 8.5.3 of GB/T 755-2019, such as the use of
thermocouples. It is understood that the electrical machine windings may be
permanently damaged, at the temperatures shown in Table 2, causing the electrical
machine inoperable.
Note 1: Rapidly changing thermal overload may be caused by the following reasons:
● Electrical machine stall;
● Phase failure;
● Start in abnormal state, such as too large inertia, too low voltage, abnormally large load torque;
● Sudden and substantial increase in load;
● Repeated starts within a short period of time.
Note 2: Based on experience, the maximum temperature limit needs to take into account the
7 Restart after tripping
Before starting the electrical machine after the protection system has tripped, an
investigation shall be carried out, to clarify the cause of the action of electrical
machine's protection device. When trying to restart the...