Voltage resistant insulation material breakdown strength tester

Voltage resistant insulation material breakdown strength tester

Frequency has a significant impact on thermal breakdown. In general, if other conditions remain constant, the E-breakdown is inversely proportional to the square root of frequency w, that is, the measurement and application of electrical strength: under specific conditions, according to standard GB/T1408.1-2016; IEC60243-1:2013; GB/T1408.2-2016; IEC60243-2:2013; ASTM D149; GB/T1695-2005; The experimental methods for frequency breakdown voltage, breakdown field strength, and withstand voltage of solid electrical materials are specified. The size of the sample, the shape of the electrode, and the method of pressurization have all been specified.

3. Thermal breakdown

The essence of thermal breakdown:

™ A medium in an electric field is heated due to dielectric loss;

™ When the applied voltage is high enough, heat dissipation and generation transition from an equilibrium state to an non-equilibrium state;

™ If the heat generation exceeds the heat dissipation, the heat will accumulate inside the medium, causing the temperature of the medium to rise;

™ The increase in temperature leads to further increase in conductivity and loss, and the temperature of the medium will continue to rise until sexual damage occurs.

12.4 Quantity of Tests - For specific materials, unless otherwise specified, 5 breakdowns should be conducted. Select the continuous boost setting method:

If it is a 50KV voltage breakdown, use the range "50". If it is a 100KV voltage breakdown, use the range "100", the protection current "5", the electrode size "75 × 25" or "25 × 25", and the peak to drop voltage, set according to the size of the sample breakdown voltage. If it is lower than 5KV, it can be set below 1KV.

Step by step boost setting method:

Set the initial voltage as "5" and the gradient voltage as "5". The gradient time can be set according to specific requirements, and other settings are the same as the continuous boost setting.

Slow boost setting method:

The setting and continuous boost setting are the same, the difference is that there are multiple initial voltages. For example, setting "5" means that there is no curve below 5KV, and the curve only appears when the voltage rises to 5KV.

Voltage withstand and boost setting method:

The setting and step-by-step boost setting are the same. The initial voltage is the voltage applied to the sample (added according to requirements), and the gradient time is the voltage applied to the sample. If there is no breakdown within the set time (set according to requirements), it is considered qualified.

4. Conduct experiments

Inject 25 # transformer oil into the oil box, overflow the upper electrode by 15-20mm, put in the sample, close the door, and the door position indicator light will turn on. Press the high voltage start button, and the green light will turn on,

Input the thickness of the sample on the computer, select the voltage boosting rate of 50KV 0.2-2kv/s, 100KV 0.5-10kv/s, and choose any one,

Click on parameter settings, select experimental method, save parameter settings, click on experimental preparation to confirm the start of the experiment. At this point, the experiment begins until the sample breaks down, the stepper motor returns to zero, the ignition indicator light is on, and the experiment ends. At this point, the computer displays the sample breakdown drop value, and the data table shows the actual value. Click on number 2 to proceed to the next sample, which can be 10 samples of one type. After completing the experiment, click on the upper left corner to save,

Click on curve analysis to view the experimental results, click on Word to convert to Word report, click on Excel to convert to Excel data for each point.

Conduct direct current experiments;

Pull out the short-circuit pin of the high-voltage transformer, open the software, double-click on the AC experiment to confirm the DC experiment, click on the DC experiment to perform the DC experiment, and the other settings are the same as the AC experiment. After completing the experiment, it will automatically discharge.

ASTM D149-2009 Test Method for Dielectric Breakdown Voltage

Voltage breakdown tester

13. Calculation

For each test, the insulation strength at breakdown should be calculated in kV/mm or V/mil units. For stepwise testing, the gradient should be calculated based on the highest voltage step at which breakdown did not occur.

13.2 Calculate the average insulation strength and standard deviation, or measure the values of other variables

Voltage breakdown tester 14. Report

14.1 The report should include the following information:

14.1.1 Identification of test samples.

14.1.2 For each test sample;

The thickness measured in 14.1.2.1,

14.1.2.2 Maximum voltage that can be withstood (for step-by-step testing),

14.1.2.3 Breakdown voltage,

14.1.2.4 Insulation strength (for stepwise testing),

14.1.2.5 Breakdown strength, and

14.1.2.6 The location of breakdown (center, edge, or exterior of the electrode).

14.1.3 For each sample:

14.1.3.1 Average dielectric strength (only for stepwise test samples),

14.1.3.2 Average dielectric breakdown strength,

14.1.3.3 Explanation of variables, preferably with standard deviation and coefficient of variation.

14.1.3.4 Explanation of test samples,

14.1.3.5 Preparation of adjustment and testing samples,

14.1.3.6 Temperature and relative humidity of the environment,

14.1.3.7 Environmental media,

14.1.3.8 Test temperature,

14.1.3.9 Explanation of electrodes,

14.1.3.10 Methods for voltage application,

14.1.3.11 If the failure criteria for current sensing components, and

Date of testing for 14.1.3.12.

ASTM D149-2009 Test Method for Dielectric Breakdown Voltage

Voltage breakdown tester

15. Accuracy and Deviation

Table 2 summarizes the results of research conducted between four laboratories and eight material laboratories. This study used the same electrode system and the same testing medium. nine

15.2 Single Operator Accuracy - The variation constant (standard deviation divided by mean) varies between 1% and 20% depending on the test material, sample thickness, voltage supply method, and the limit of controlling or suppressing instantaneous voltage pulses. If five test samples of the same sample are tested repeatedly, the change constant is usually not greater than 9%.

Table 2: Insulation Strength Data A Summarized from Four Laboratories

A test sample was tested in oil using a type 2 electrode (see Table 1).

15.3 Multi laboratory Accuracy - The accuracy of testing varies in different laboratories (or on different equipment in the same laboratory). By using the same type of equipment and strictly controlling the preparation of test samples, electrodes, and testing processes, the accuracy of a single operator is approximate. But if comparing results from different laboratories, it is necessary to evaluate the accuracy of different laboratories.

The 9 supporting data have been archived at ASTM International Headquarters and can be obtained by applying for research report RR: D09-1026.

If the test material, sample thickness, electrode structure, or environmental medium is different from those listed in Table 1, or if the breakdown standard of the current sensing element in the testing equipment is not strictly controlled, the accuracy specified in 15.2 and 15.3 cannot be achieved. For the material that needs to be tested, the standards related to this testing method should be able to determine the accuracy applicable range of the material. Refer to sections 5.4~5.8 and 6.1.6.

15.5 Use special techniques and equipment to achieve an accuracy of 0.01 inches or even less in material thickness. The electrode must not damage the contact surface of the sample. Accurately measure the breakdown voltage.

15.6 Deviation - This testing method cannot determine the inherent insulation strength. The test results depend on the geometric shape of the sample, electrode and other variable parameters, as well as the properties of the sample, which makes it difficult to describe deviations.

Voltage breakdown tester

16. Keywords

16.1 Breakdown, breakdown voltage, calibration, breakdown standard, dielectric breakdown voltage, dielectric failure, dielectric strength, electrode, flashover, power frequency, process control testing, verification testing, quality control testing, rapid increase, research testing, sampling, slow speed, gradual, environmental medium, withstand voltage.

Appendix

(Non mandatory information)

The significance of Xl. insulation strength testing

X1.1 Introduction

A brief review was conducted on the three assumed mechanisms of breakdown, namely: (1) discharge or corona mechanism, (2) thermal mechanism, and (3) intrinsic mechanism. The factors that affect actual dielectrics in principle were discussed, and assistance was provided for interpreting the data. The breakdown mechanism is often combined with other mechanisms rather than acting independently. The subsequent discussion will only focus on solid and semi-solid materials. The assumed mechanism of dielectric breakdown is breakdown caused by discharge - in many tests on industrial materials, breakdown is caused by discharge, which typically results in higher local fields. For solid materials, discharge often occurs in the environmental medium, so increasing the testing area will result in breakdown at the edge or outside of the electrode. The discharge will also occur in some foam or bubbles that appear or are generated inside. This can cause local erosion or chemical decomposition. These processes will continue until a failure pathway is formed between the electrodes. Thermal breakdown - When placed in a high-intensity electric field, a large amount of heat accumulates on local paths within many materials, causing loss of dielectric and ionic conductivity, and rapidly generating heat, which will be greater than the amount of heat that can be dissipated. Due to the thermal instability of the material, breakdown occurred.

Inherent breakdown - If neither discharge nor thermal stability can cause breakdown, breakdown will still occur when the electric field strength is strong enough to accelerate electrons through the material. The standard electric field strength is called intrinsic insulation strength. Although the mechanism itself may have been involved, this testing method still cannot test the inherent insulation strength. The properties of insulating materials: Solid state industrial insulating materials are usually non-uniform and contain many different dielectric defects. The areas where breakdown often occurs on the sample are not the areas with the highest electric field strength, sometimes even those far away from the electrode. The weak links in the stress roll can sometimes determine the test results. Factors affecting testing and sample condition - Typically, as the electrode area increases, the breakdown voltage decreases, and this effect is more pronounced for thin samples. The geometric shape of the electrode can also affect the test results. The material used to make the electrode can also affect the test results, as the thermal conductivity and work function of the electrode material can affect the thermal and power generation mechanisms. Generally speaking, it is difficult to determine the influence of electrode materials due to the lack of relevant experimental data. Sample thickness - The insulation strength of solid industrial insulation materials mainly depends on the thickness of the sample. Experience has shown that for solid and semi-solid materials, insulation strength is inversely proportional to the fraction with the sample thickness as the denominator. More evidence suggests that for relatively uniform solids, insulation strength is inversely proportional to the square root of the thickness. If the solid sample can be melted and poured between fixed electrodes and solidified, it will be difficult to define the effect of electrode spacing clearly. Because in this case, the electrode spacing can be fixed freely, it is customary to conduct insulation strength tests in liquids or soluble solids, where there is a standard fixed space between the electrodes. Because insulation strength depends on thickness, if the initial thickness of the test sample used for testing is missing when reporting insulation strength data, such data will be meaningless.

Temperature - The temperature of the sample and environmental medium will affect the insulation strength, although for most materials, small changes in environmental temperature can have a negligible impact on the material. Usually, the insulation strength decreases with increasing temperature, but the limit of its strength depends on the tested material. Due to the need for materials to function under conditions other than room temperature, it is necessary to determine the relationship between insulation strength and temperature within a larger range than the expected operating temperature. Time - the rate at which voltage is applied can also affect the test results. Usually, the breakdown voltage increases with the increase of voltage application rate. This is expected because the thermal breakdown mechanism depends on time, while the discharge mechanism also depends on time, although in some cases, the latter mechanism causes rapid failure waveforms by generating local electric fields with high critical strength - usually, the waveform of the applied voltage also affects the insulation strength. In the limitation statement of this testing method, the influence of waveform is not significant. Frequency - For this testing method, the impact of frequency changes on insulation strength will not be as significant within the frequency range of industrial electricity. However, it cannot be inferred from the results obtained by this testing method that other non industrial electrical frequencies (50 to 60HHz) have an impact on insulation strength.

X1.4.7 Environmental media - Solid insulation materials with high breakdown voltage are typically tested by immersing the sample in a liquid medium, such as transformer oil, silicone oil, or Freon, to reduce the impact of surface discharge before breakdown. This has been revealed by S. Whitehead10. In order to avoid discharge of solid samples in the ambient medium before reaching the breakdown voltage, it is necessary to ensure that:

（X1.1）

If the immersed liquid medium is a low loss material, the formula can be simplified as:

（X1.2）

If the immersed liquid medium is a semiconductor material, then the formula can be changed to:

（X1.3）

Where:

E=insulation strength;

F=frequency;

ε and ε′=dielectric constant;

D=dissipation factor;

O=conductivity (S/m);

Index:

M refers to immersion in a medium;

R refers to the relative value;

O refers to free space;

（εO=8.854×10-12F/m）

S refers to solid dielectric materials.

X1.4.7.1 Whitehead pointed out that to avoid surface discharge, one should increase Em and ε m or increase σ m. It is usually stipulated to use transformer oil, and its dielectric properties are as follows: if the electric field strength Es reaches the following level, edge breakdown will occur:

（X1.4）

If the test sample is thick and its dielectric constant is small, the amount of ts will become the relative influencing factor, and the product of dielectric constant and electric field strength will approximate a constant. Whitehead also pointed out (p. 261) that using moist semiconductor oil can effectively reduce the phenomenon of edge discharge. If the breakdown path between electrodes only occurs in solids, then this medium cannot be compared with other media. It should also be noted that if the solid is porous or can be filled with an immersion medium, the breakdown strength of the solid will be directly affected by the electrical properties of the immersion medium.

X1.4.8 Relative Humidity - Relative humidity affects insulation strength because the moisture absorbed by the test material or adsorbed on the surface will affect the dielectric loss and surface conductivity. Therefore, its importance largely depends on the properties of the testing material. However, even if the material only absorbs a little or no water, it will still be affected because in the presence of water, the chemical effect of discharge will be greatly enhanced. In addition, the effects of exposure to electric field strength should also be investigated, usually through standard adjustment procedures to control or limit the impact of relative humidity.

10 References: Whitehead, S., Solid dielectric breakdown, Oxford University Press, 1951

X1.5 Evaluation

X1.5.1 A basic requirement for the insulation of energized equipment is that it should be able to withstand the voltage applied to it during service. Therefore, it is necessary to evaluate the testing to assess the material properties under high-pressure stress conditions. Dielectric breakdown voltage testing is a preliminary test to determine whether a material requires further investigation, but it cannot fully evaluate two important aspects. Firstly, the material conditions installed on the equipment are significantly different from the testing conditions, especially after considering the electric field structure and the material area exposed to the electric field, corona, mechanical stress, surrounding media, and connections with other materials. Secondly, during service, there will be many adverse effects such as heat, mechanical stress, corona and its products, pollutants, etc., which will cause the breakdown voltage to be much lower than the initial breakdown voltage value during installation. In laboratory testing, some of these influences can be combined to make more accurate estimates of the material, but ultimately the properties of the material that are in actual service are still examined.

X1.5.2 Dielectric breakdown testing can be used as a material inspection or quality control test, as a means of inferring other conditions such as variability, or to indicate deterioration processes such as thermal aging. When using this testing method, the relative value of breakdown voltage is more important than the absolute value.

X2. Standards involved in D149 testing method

X2.1 Introduction

X2.1.1 The document directory provided in this appendix will involve a large number of ASTM standards, which are related to the determination of dielectric strength at power frequency, or to the components of testing equipment or components used to determine this property. Although we have made every effort to include all standards related to the D149 testing method, this list is still not included, and standards written or modified after the publication of this appendix have not been included.

X2.1.2 In some standards, the D149 test method is used to determine dielectric strength or breakdown voltage, but its reference to this test method may not necessarily meet the requirements of 5.5. Unless the document is consistent with 5.5, no other documents, including those listed in this directory, need to be used as references for this testing method.

ASTM D149-2009 Test Method for Dielectric Breakdown Voltage

Table X2.1 ASTM standards referenced in Test Method D149

14、 Report

Unless otherwise specified, the report shall include the following content

a) The full name of the tested material, description of the sample and its preparation method for the dielectric breakdown tester (dielectric breakdown test);

b) The median electrical strength of the dielectric breakdown tester (dielectric breakdown test) is less than kV/mm, or the median breakdown voltage is expressed in kV;

c) Dielectric breakdown tester (dielectric breakdown test) with a thickness of less than 5.4 for each sample;

d) The surrounding media and their properties used during the experiment;

e) Electrode system;

f) The method and frequency of applying voltage;

g) The various values of electrical strength (expressed in kV/mm>or the various values of breakdown voltage<expressed in kV);

h) The temperature, pressure, and humidity when tested in air or other gases, and the temperature of the surrounding medium when tested in liquid;

i) Pre experimental condition treatment;

j) Explanation of breakdown type and location.

If only a simple result report is needed, the first 6 items and their low and high values should be reported.

Voltage resistant insulation material breakdown strength tester

1. The experiment is conducted in the test box, and when the door of the test box is opened, the power supply cannot be applied to the input terminal of the high-voltage transformer, that is, there is no voltage on the high-voltage side. The nearest distance between the high-voltage electrode of the 100KV testing equipment and the test box wall is greater than 270mm, and the nearest distance between the high-voltage electrode of the 50KV testing equipment and the test box wall is greater than 250mm. Even if people come into contact with the box wall during the test, there will be no danger.

2. The equipment needs to be equipped with a separate protective grounding wire. Grounding protection is mainly used to reduce the strong electromagnetic interference caused by the breakdown of the sample to the surrounding area. It can also prevent the computer from losing control.

3. The circuit of the experimental equipment is equipped with multiple protection measures, mainly including overcurrent protection, overvoltage protection, leakage protection, short circuit protection, DC test discharge alarm, electromagnetic discharge, etc.

4. DC test discharge alarm function: When the device completes the DC test, the device will automatically alarm when the test door is opened, and the alarm will be automatically cancelled after the discharge device on the device is used for discharge (Note: Failure to discharge electricity after DC testing can pose a danger to human safety, and the electrode cannot be directly taken to remind users to discharge to avoid injury).

5. Experimental discharge device, automatic discharge placement of electromagnet. meet the standard

GB1408.1-2016 "Test Methods for Electrical Strength of Insulation Materials Part *"; Test under Power Frequency, Part 2

GBT13542.1-2009 Thin Films for Electrical Insulation Part *

GB/T1695-2005 "Determination method for power frequency breakdown voltage strength and withstand voltage of vulcanized rubber"

GB/T 3333-1999 "Test Method for Power Frequency Breakdown Voltage of Cable Paper" Scope 1

This part of GB/T 13542 specifies the definition, general requirements, dimensions, inspection rules, marking, packaging, and transportation of thin films for electrical insulation

Transportation and storage.

This section applies to thin films for electrical insulation,

2 Normative References

The clauses in the following documents are referred to as clauses in this section of GB/T 13542. Any citation with a date

All subsequent modification orders (excluding errata) or revised versions are not applicable to this section. However, it is encouraged to reach an agreement based on this section

The parties to the agreement are studying whether the latest versions of these documents can be used. The latest version of any referenced document without a date shall apply to this document

part

GB/T 13542.2-2009 Thin Films for Electrical Insulation Part 2: Test Methods (IEC60674-2:1988, MOD)

3 Terms and definitions

The following terms and definitions apply to this section.

3.1

Windability of winding

The winding performance of the film is used to evaluate the deformation of the rolled film, which can be measured by two aspects: offset/curvature and indentation.

3.1.1

Offset/Arc Bias Camber

When the film is opened flat, its edges do not form a straight line (offset or arc)

3.1.2

depression

sag

When a section of film is supported by two parallel rollers in a horizontal position and subjected to a certain tension, some of the film will be lower than the total

The horizontal plane. Special requirements for joint heat resistance or solvent resistance should be negotiated between the supply and demand parties.

4.4 Tube core

The film should be wound on a circular core, and the core should not shed chips, collapse, or twist under winding tension, nor should it damage the film or reduce its performance

Low. All performance and dimensions of the die, as well as their deviations, shall be negotiated between the supply and demand parties. The preferred inner diameters of the die are 76 mm and 152 mm, and the die can be

Extend the end of the film roll or align it with the end.

5 sizes

5.1 Thickness

Measure the thickness according to the method described in Chapter 4 of GB/T 13542.2-2009, unless otherwise specified in the product standard, and the measured thickness

Should be within ± 10% of the nominal value.

5.2 Width

The width should be specified in the product standard and measured according to the method specified in Chapter 6 of GB/T 13542.22009, unless otherwise specified in the product standard

Unless otherwise specified, the allowable deviation shall comply with the provisions of Table 1.

Table 1 Film Width

Unit in millimeters

width

bias

≤50

±0.5

>50~300

±1.0

>300~450

±2.0

>450

±4.0

5.3 Length

The requirements for length are specified by product standards.

The inspection rules GB/T 13542 "Thin Films for Electrical Insulation" are divided into the following parts:

Part 1: Definition and General Requirements;

Part 2: Experimental Methods;

Part 3: Biaxially oriented polypropylene thin film for capacitors;

Part 4: Polyester Film

.

This section is the first part of GB/T13542.

This section is modified to adopt IEC60674-1:1980 "Plastic films for electrical purposes - Part 1: Definitions and general requirements" (English version).

The main technical differences between this section and IEC60674-1 are as follows:

1) Added a chapter on 'Normative References';

2) Added a chapter on 'Inspection Rules'.

This section replaces GB/T 13542-1992 "General Requirements for Plastic Film for Electrical Use",

The main differences between this section and GB/T 13542-1992 are as follows:

1) Change 'reference standard' to 'normative reference document'

2) Change "skew" to "offset/arc" in Definition 3.1.1.

This section was proposed by the China Electrical Appliances Industry Association.

This section is under the jurisdiction of the National Technical Committee for Standardization of Insulation Materials (SAC/TC51),

Our drafting units are Guilin Institute of Electrical Science and Dongcai Technology Group Co., Ltd.

The main drafters of this section are Wang Xianxiu and Zhao Ping.

The previous versions of the standards replaced by this section are:

GB/T13542-1992。

6.1 The film should undergo factory inspection and type inspection.

6.2 The type inspection items refer to all the technical requirements specified in the product standard, and shall be conducted at least once every three months. When there is a change in raw materials

When the process conditions change, type inspection should also be conducted.

6.3 The batch size, sampling method, and factory inspection items of the product are specified in the product standard. Each batch of film should undergo factory inspection, and the product should be inspected

Qualified before leaving the factory. The manufacturer shall ensure that the products leaving the factory meet all technical requirements specified in the product standards.

When any of the test results does not meet the technical requirements, a set of samples should be taken from each of the other two rolls of the batch of film to repeat the test

If there is still one group that does not meet the requirements, the batch of films is considered as unqualified.

6.5 The user unit may conduct acceptance inspection according to all or part of the product standards. Preprocessing conditions shall be in accordance with GB/T13542.2-2009

Requirement 3.2 requires it to be carried out.

When requested by the user, the manufacturer shall provide a product inspection report.

7 Marking, packaging, transportation, and storage

7.1 The film roll should be wrapped in moisture-proof paper or plastic film, wrapped in a plastic bag on the outer layer, and placed in an elevated support in the packaging box, so that the film is in normal condition

Fully protected from damage and deterioration under storage and transportation conditions.

7.2 Each box of film should have clear and sturdy markings:

TVS instantaneous suppression protection technology

Multi level cyclic voltage acquisition technology:

After material breakdown, the instantaneous discharge speed is about 1/5~1/3 of the speed of light. The internationally recognized method for collecting breakdown voltage is the voltage drop method. The instantaneous decrease of the primary voltage of the transformer by a certain ratio is used to determine whether the material has broken down. Obviously, there is a deviation in recording the breakdown voltage value. The use of multi-level cyclic acquisition technology to collect the voltage after breakdown will solve this problem.

Low pass filtering current monitoring technology:

High frequency signals will be generated during the high-voltage discharge process. Both domestic and imported current collection sensors are mostly power frequency current sensors. When high-frequency signals cannot be processed during the collection process, it leads to inaccurate detection. Regardless of whether the sensor is designed using a flux gate or Hall principle, there may be an instantaneous output voltage or current signal that is too large after breakdown, thereby burning out the acquisition part of the control system. The low filtering current acquisition sensor developed by Huace processes high-frequency clutter signals accordingly. The protection module independently developed by Huace for same current collection ensures collection accuracy and protects collection components.

● Dual system interlocking technology and isolation shielding technology:

The dual system interlock technology is applied to electrical breakdown instruments, and the produced voltage breakdown instruments not only have overvoltage and overcurrent protection systems, but also have a dual system interlock mechanism. When any component has a problem or a single system fails, the high voltage will be instantly cut off.

Product Name: Voltage breakdown tester

Product models: BDJC-10KV, BDJC-50KV, BJC-100KV

Product brand: Beijing Beiguang Jingyi

Control method: computer-controlled

Compliant with standards such as GB/T1408, ASTM D149, IEC60243-1, etc

Applicable materials: rubber, plastic, film, ceramic, glass, paint film, resin, wire and cable, insulation oil and other insulation materials

Test items: breakdown voltage test, dielectric strength test, electrical strength test, withstand voltage breakdown strength test, etc

Test voltage: 10KV, 20KV, 50KV, 100KV, 150KV, etc

Voltage accuracy: ≤ 1%

Applicable materials: Insulation materials

Boosting rate: 10V/S-5KV/S

Test methods: AC/DC, withstand voltage, breakdown, gradient boosting

Control system: PLC controls voltage rise

Core components: using imported accessories

Test medium: insulating oil, air

Display mode: curve display, data printing

Other features: Wireless Bluetooth control

Equipment composition: host, computer, electrode

Electrode specifications: 25mm, 75mm, 6mm

Electrical capacity: 3KVA, 5KVA, 10KVA

Voltage endurance time: 0-8H

Security protection: Level 9 security protection

Warranty period: Three years, lifetime maintenance.