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GB/T 31137-2014 PDF in English


GB/T 31137-2014 (GB/T31137-2014, GBT 31137-2014, GBT31137-2014)
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GB/T 31137-2014: PDF in English (GBT 31137-2014)

GB/T 31137-2014
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 25.180.10
K 61
Temperature controller for laboratory resistance furnaces
ISSUED ON: SEPTEMBER 3, 2014
IMPLEMENTED ON: FEBRUARY 1, 2015
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Product classification ... 7
5 Technical requirements ... 10
6 Test methods ... 16
7 Inspection rules and technical classification ... 19
8 Marking, packaging, transportation and storage ... 20
9 Ordering and supply ... 21
Temperature controller for laboratory resistance furnaces
1 Scope
This Standard specifies various requirements for KSB, KSD, KSG, KSJ and KSY series
temperature controllers for laboratory resistance furnaces (hereinafter referred to as
temperature controllers), including product classification, technical requirements, test
methods, inspection rules, technical classification and ordering and supply.
This Standard applies to temperature controllers matched with SX, SK and SG series
laboratory box-type, tube-type and pot-type resistance furnaces.
For other temperature controllers used in laboratory resistance furnaces, this Standard
is for reference only.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB 1094.11-2007 Power transformers - Part 11: Dry-type transformers
GB/T 2900.23-2008 Electrotechnical terminology - Industrial electroheat
GB/T 4025-2010 Basic and safety principles for man-machine interface, marking
and identification - Coding principles for indicators and actuators
GB/T 4026-2010 Basic and safety principles for man-machine interface, marking
and identification - Identification of equipment terminals and conductor terminations
GB 4208-2008 Degrees of protection provided by enclosure(IP code)
GB 4884-1985 Marking of insulated conductors
GB 7947-2010 Basic and safety principles for man machine interface, marking and
identification - Identification of conductors by colours or alphanumerics
GB/T 10066.1-2004 Test methods for electroheat installations - Part 1: General
GB/T 10067.1-2005 Basic specifications for electroheat installations - Part 1:
General
GB/T 13324-2006 Terminology of heat treatment equipment
h) temperature control accuracy, °C;
i) overall dimensions of the control box (width × depth × height), mm;
j) weight, kg.
5 Technical requirements
5.1 General requirements
The temperature controller shall comply with the relevant provisions of Clause 5 of
GB/T 10067.1-2005. When there is a difference between the provisions of that standard
and this Standard, this Standard shall prevail.
5.2 Supplementary requirements for design and manufacturing
5.2.1 Overall design
The temperature controller for laboratory resistance furnaces refers to the assembly of
software and hardware units such as electrical control components and instruments that
are centrally installed in the temperature control box to achieve heating temperature
measurement, control and recording functions. Because the heating capacity of
laboratory resistance furnaces is small and generally not partitioned, it is different from
the temperature control cabinet for industrial resistance furnaces, and is called a
temperature controller. The temperature controller can be in a separate box or integrated
with the furnace.
The temperature controller can be composed of a box (station) body, a frame and
various electrical components, devices and instruments. The design of the temperature
controller shall be able to ensure that the heat, arc, impact, vibration, magnetic field or
electric field generated by the operation of each electrical component must not interfere
with each other’s normal functioning.
5.2.2 Box (station) body
The temperature controller is generally a separate box (station) body, connected to the
heating body in the furnace through a cable, or it can be directly connected to the
furnace body as a whole. The door or top cover of the temperature controller shall have
hidden buckles or internal pins and shall be able to rotate flexibly. Its opening angle
shall not be less than 90°. Electrical components and instruments shall not be impacted
during the opening process.
Separate holes shall be made on the box (station) body for signal wiring and lead-out
wiring such as thermocouples, actuators, detection switches, etc.
5.2.3 Installation requirements
All components, devices and instruments installed in the temperature controller must
be inspected and qualified before installation. During installation, sufficient distance
for disassembly and repair shall be left according to design requirements. The
contactors and instruments in the temperature controller shall be equipped with
appropriate anti-vibration measures (for example, adding spring washers or rubber pads)
according to the actual working conditions. The wire outlet holes shall be equipped with
insulating outlet rings.
5.2.4 Painting requirements
The paint film surface of the temperature controller must not have defects such as
wrinkles, flow marks, pinholes and blisters.
The paint film on the outer surface of the temperature controller shall be uniform in
color, flat and smooth, and no brush marks, scars, correction marks, obvious mechanical
impurities, spots, etc. that can be seen with the naked eye; the paint film on the inner
surface of the temperature controller shall have a certain anti-corrosion ability.
The outer surface of Class C temperature controller shall be painted or epoxy powder
sprayed, etc. If there are special requirements (see 9.2), they can be agreed upon by
both parties.
5.2.5 Electrical system
5.2.5.1 Power supply
The power supply parameters of the temperature controller are determined according
to the relevant contents in Table 1.
5.2.5.2 Wires
The connecting wires in the temperature controller shall be wired correctly, firmly,
reliably, and arranged neatly and beautifully. The cross-sectional area of the conductor
shall be selected according to the specified carrying capacity. It is generally not less
than 0.75 mm2 for single-core copper insulated wires, and generally not less than 0.5
mm2 for multi-core copper insulated wires.
The connecting wires to each connector shall have copper bare crimp terminals. There
shall be no plugged or soldered transition connections in the middle of each conductor.
The insulated wire markings inside the temperature controller shall comply with the
provisions of GB 4884-1985. The markings shall be printed with a printing machine,
and the writing shall be clear and durable to facilitate use and maintenance.
The color of the wires in the temperature controller shall comply with the provisions of
GB 7947-2010.
5.2.5.3 Terminal blocks
The identification and alphanumeric symbols of the terminal blocks in the temperature
controller shall comply with the provisions of GB/T 4026-2010.
5.2.5.4 Indicators and buttons
The colors of the indicator lights and buttons used on the temperature controller shall
comply with the relevant provisions of GB/T 4025-2010.
5.2.5.5 Temperature control instruments
Class C temperature controllers shall be equipped with digital display programmable
temperature control instruments with a microprocessor, of which the temperature
indication accuracy is not less than ±0.25 %, the setting accuracy is not less than ±0.5 %,
and the resolution is not less than 1 °C (excluding display error). The digital display
shall be clearly legible and its height shall not be less than 15 mm. The instrument shall
be equipped with a data interaction interface so that a recorder or printer can be
connected when necessary.
Class B and Class A temperature controllers shall be equipped with temperature control
instruments, of which the temperature indication accuracy is not less than ±0.5 % and
the setting accuracy is not less than ±1 %.
When otherwise specified (see 9.2), Class A temperature controllers may also be
equipped with temperature control instruments, of which the temperature indication
accuracy is not less than ±1 % and the setting accuracy is not less than ±1 %.
5.2.5.6 Electrical instruments
The temperature controller shall be equipped with necessary voltmeters and ammeters.
When required (see 9.2), it can also be equipped with other electrical instruments. The
accuracy level of the electrical instruments shall not be lower than level 2.5.
5.2.5.7 Over-temperature control system
When required (see 9.2), the temperature controller shall be equipped with an over-
temperature control system.
The over-temperature control system shall comply with the relevant provisions of 5.2.7
in JB/T 8195.7-2007, JB/T 8195.8-2007 and JB/T 8195.9-2007.
5.2.5.8 Transformers
The transformers used with KSB series temperature controllers shall comply with the
provisions of GB 1094.11-2007.
5.2.5.9 Others
5.4.2 Degree of protection provided by enclosure
The protection provided by enclosure of the temperature controller shall not be lower
than the requirements of IP31 degree in GB 4208-2008.
5.4.3 Interlocking
As needed, the temperature controller shall be interlocked with the furnace door
opening and over-temperature control system of the laboratory resistance furnace, to
prevent accidents that endanger personal or equipment.
5.5 Requirements for complete set
The supply scope of complete set of the temperature controller specified by the supplier
shall be listed in the enterprise product standards. These include:
a) box (station) body (including temperature control instruments, electrical
components, actuators, etc.);
b) transformer (applicable to KSB series);
c) instructions for use;
d) spare parts (including fuses, etc.).
In the enterprise product standards, the specific contents of the above items shall be
listed, including model, specification and quantity.
If the purchaser has different requirements for the items specified by the supplier, it
may be submitted in accordance with 9.2.
6 Test methods
6.1 General
The test methods for temperature controllers shall comply with the relevant provisions
of GB/T 10066.1-2004 and the following supplementary provisions.
During the test, the special temperature controller shall be connected to the
corresponding special laboratory furnace. For a standard temperature controller, the
rated power of the box-type laboratory furnace it connected to shall be equal to 70 % ~
100 % of the maximum control power of the temperature controller, and the maximum
operating temperature shall be equivalent to the maximum temperature of the
temperature controller. The laboratory furnace used for measurement shall be a
qualified product that has been inspected by the inspection department. The use of
temperature-controlled thermocouples shall be the same as the temperature
measurement conditions of the laboratory furnace during normal operation, and
generally shall have a protective cover.
6.2 Measurement of insulation resistance
Use a 500 V megger to measure between different charged objects in the temperature
controller and between each charged object and the metal shell.
Components that cannot withstand the 500 V megger voltage shall be disconnected or
short-circuited before the measurement.
6.3 Dielectric strength test
The dielectric strength test is carried out after the measurement of insulation resistance.
The dielectric test voltage is a power frequency sinusoidal waveform, which is applied
between different charged objects and between each charged object and metal when the
temperature controller is working normally. The latter shall be connected at together
and grounded.
The dielectric test voltage shall start from half of the voltage value specified in Table 3,
gradually increase to the full value within 10 seconds, and then maintain for 1 minute.
Flash explosion or breakdown shall not occur.
Instruments and components that cannot withstand the above dielectric test voltage
shall be disconnected or short-circuited before the test.
6.4 Power-on test
During the test, the temperature controller shall be connected to a resistor of which the
rated power is 50 % ~ 100 % of the maximum output power of the temperature
controller. After the power is turned on, check whether the electrical components and
instruments operate normally.
6.5 Measurement of surface temperature rise
The measurement of surface temperature rise shall be carried out after the temperature
controller operates normally and reaches the thermal equilibrium state.
Surface temperature rise shall be measured using a surface thermometer or surface
thermocouple with an accuracy of not less than level 4.
6.6 Measurement of temperature control accuracy
30 minutes after the laboratory resistance furnace reaches its maximum operating
temperature, the temperature of the temperature-controlled thermocouple shall be
continuously tracked and monitored for at least 30 minutes, and the maximum and
minimum temperature values of each temperature adjustment or fluctuation period
during the entire monitoring period shall be recorded, respectively. The average of the
five larger maximum values and the average of the five smaller minimum values are
used as the maximum and minimum measured temperature values.
During the above tracking and monitoring period, the temperature of the temperature-
controlled thermocouple shall be recorded regularly every 3 minutes to obtain the
average temperature during the period (which is the average of at least 11 temperature
recording values).
The largest value among the absolute values of the differences between the maximum
(average value) and minimum (average value) measured temperature values AND the
average value of the control temperature is the temperature control accuracy of the
temperature controller.
6.7 Power adjustment test
Applicable to KSG series temperature controllers.
After the temperature controller is connected to the no-load laboratory resistance
furnace specified in this Clause and powered on, manually adjust the output power
through the potentiometer or manual output button of the instrument, so that the
indicated value of the main circuit ammeter goes from minimum to maximum, and then
decreases smoothly to zero. Repeat this three times and there shall be no abnormality.
6.8 Output voltage regulation test
Applicable to KSB and KSY series temperature controllers.
After the temperature controller is connected to the no-load laboratory resistance
furnace specified in this Clause and powered on, manually adjust the output voltage
through the potentiometer or manual output button of the instrument. Its value shall be
adjustable within the range specified in 5.3.7.
6.9 Main circuit waveform inspection
After connecting the control circuit and the main circuit, use an oscilloscope to check
the voltage and current waveforms of the main circuit. The waveforms shall meet the
requirements of 5.3.8. If necessary, for a temperature controller used for inductive loads,
take photos of the voltage and current waveforms at the moment when the main circuit
is turned on.
6.10 Protection system inspection
6.10.1 Overcurrent protection inspection
Applicable to KSG and KSY series temperature controllers.
Set the overcurrent setting value of the overcurrent system of the temperature controller
to the specified value, and then make the main circuit pass a current equal to the setting
value, check whether the overcurrent protection system can operate normally.
6.10.2 Short-circuit protection test
Applicable to KSG and KSY series temperature controllers.
If the main circuit output line is artificially short-circuited, the quick fuse shall be blown
and the components in the temperature controller shall not be damaged.
6.10.3 Overvoltage protection inspection
Applicable to KSG and KSY series temperature controllers.
The overvoltage of the temperature controller comes from the on-off and overcurrent
of the switching element, the disconnection of the short-circuit protection, etc.
Therefore, this inspection shall be carried out at the same time as the tests and
inspections of 6.3, 6.10.1 and 6.10.2, and the components in the temperature controller
after the inspection shall not be damaged.
7 Inspection rules and technical classification
7.1 The inspection and technical classification of temperature controllers shall be
carried out in accordance with the provisions of Clause 7 of GB/T 10067.1-2005 and
the following clauses.
7.2 The factory-exit inspection items of temperature controllers shall include the
following items:
a) General inspection;
b) Measurement of insulation resistance;
c) Dielectric strength test;
d) Power-on test;
e) Output voltage regulation test (applicable to KSB and KSY series);
f) Overcurrent protection check (applicable to KSG and KSY series);
g) Inspection of accessories, including inspection of models, specifications and
factory-exit certificates;
h) Inspection of the scope of supply, including inspection of the completeness of
factory-exit technical documents;
d) number of phases;
e) maximum control power, kW;
f) weight, kg;
g) serial number of the product;
h) date of manufacture;
i) name of the manufacturer (the name of the country shall be indicated for exported
products).
9 Ordering and supply
9.1 The ordering and supply of temperature controllers shall be in accordance with the
provisions of Clause 9 of GB/T 10067.1-2005.
9.2 If the purchaser has the following special requirements, it may submit them to the
supplier:
a) Different requirements for unit system, power supply voltage, power frequency,
etc. (see 5.1.1.1 in GB/T 10067.1-2005);
b) Different requirements for the use environment (see 5.1.2 in GB/T 10067.1-2005);
c) Additional requirements for safety and environmental protection (see 5.1.5.1 in
GB/T 10067.1-2005);
d) Different requirements for paint (see 5.2.7 in GB/T 10067.1-2005 and 5.2.4 of
this Standard);
e) Special requirements for packaging (see 8.2.4 in GB/T 10067.1-2005);
f) Different requirements for temperature control instruments (see 5.2.5.5);
g) Different requirements for electrical instruments (see 5.2.5.6);
h) Requirement of providing an over-temperature control system (see 5.2.5.7);
i) Different requirements for the supply items specified by the supplier (see 5.5).
The supplier shall try its best to meet the special requirements of the purchaser.
However, the actual special requirement items that can be selected by the purchaser are
determined by the supplier with reference to this Standard. Some of them can be listed
in the enterprise product standards, and the other parts can be agreed upon by both
parties when ordering.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.