MT/T 1078-2008Direct current power supply with intrinsically safe output for a coal mine (English PDF)

3.1 Model

Model of product shall be in accordance with the specifications of MT/T 286.

3.2 Classification

3.2.1 According to explosion proof type.

3.2.2 According to operating principle.

3.2.3 According to output function.

4.1 General requirements

DC power supply shall meet the requirements of this Standard, MT/T 1004, AQ 6201,

etc., and shall be produced according to drawing and technical documents approved

by specified procedure.

4.2 Environmental condition

4.3 Rated power supply condition

4.3.1 Source voltage. in accordance with Table 3.

4.3.2 Source frequency. 50 Hz, permissible deviation is ± 5%.

4.3.3 Harmonic wave. not more than 10%.

4.4 Main technical parameters

4.4.1 AC rated input voltage

AC rated input voltage shall meet input of 127 V and 220 V, it can also be chosen from

4.5 Main functions

4.5.1 It shall have input and output power supply indication function.

4.5.2 It shall have current-limiting, voltage limiting and short circuit protection function,

thus automatic recovery can be made after fault is removed.

4.5.3 AC power supply with standby battery.

4.6 Structure

4.6.1 Fasteners shall have measures that avoid automatic loose.

4.8 Protective function of enclosure

Protective function of enclosure shall be in accordance with GB 3836.1 ~ GB 3836.4,

GB 3836.9, GB 12173 and other relevant standards.

4.9 Electric safety

4.9.1 Insulation resistance between circuit with power of DC power supply and

grounding (or enclosure) shall be in accordance with Table 4.Measurement locations

shall be specified in relevant standards.

4.14.4 AC power supply shall pass storage in low temperature working test; the main

technical parameters, functions and appearance shall not be below requirements of

this Standard.

4.15 Explosion-proof performance

AC power supply of explosion proof type shall be in accordance with the relevant

specifications of GB 3836.1 ~ GB 3836.4 and GB 3836.9, which shall have dual or

multiple current-limiting, voltage limiting and circuit protection function.

4.16 Performance of mining general type

Performance of mining general type shall be in accordance with the specifications of

GB 12173.

4.17 Intrinsically safe parameters

4.17.1 The highest output voltage shall meet requirements of intrinsically safe

explosion proof and shall be specified in relevant standards.

4.17.2 Maximum output current shall meet requirements of intrinsically safe explosion

proof and shall be specified in relevant standards.

5.1 Environmental conditions

Unless otherwise specified in environmental test and relevant standards, test shall be

conducted in the following environmental conditions.

5.2 Main technical parameters and main function test

5.2.1 Measuring apparatus and equipment

5.2.1.1 General requirements for measuring apparatus and equipment

5.2.1.2.3 Artificial load. Adjust the artificial load to obtain load current, maximum

output current and circuit current that are needed by AC power supply output test.

5.2.1.2.4 Voltage regulator. it shall be in accordance with requirements of relevant

standards.

5.2.1.2.5 Oscilloscope, storage oscilloscope and video milli-voltmeter. it shall meet

requirements of relevant standards.

5.2.2 Test circuit

Connect test equipment according to figure 1, S1 and S2 in figure are single-phase

switches.

Figure 1 Test circuit

5.2.3 Test steps

5.2.3.5 Current limiting and short circuit protection function

SET source voltage as specified maximum value, ADJUST artificial load to make load

current gradually increase to output short circuit. OBSERVE ampere meter (A), the

maximum current is maximum output current of AC power supply, final indicating

value is short circuit current of AC power supply. REMOVE over-current and

short-circuit faults, INSPECT whether AC power supply can recover by itself or not.

CARRY out test for 5 times continuously.

For multi-circuit output AC power supply, output of other circuits shall be rated load.

5.4 Appearance inspection

ADOPT visual inspection.

5.5 Enclosure protective performance inspection

Enclosure protective performance inspection shall be conducted in accordance with

the relevant specifications of GB 4208.

5.6 Measurement of insulation resistance

Measurement of insulation resistance shall be conducted in accordance with the

relevant specifications of MT 210.

5.10 Anti-interference test

Anti-interference test shall be conducted in accordance with the specifications of GB/T

17626.3-2006, GB/T 17626.4-1998 and GB/T 17626.5-1999.

5.11 Reliability test

Reliability test shall be conducted in accordance with the relevant specifications of

GB/T 5080.7, ADOPT fixed time test plan. Failure judgment shall be conducted in

accordance with the relevant specifications of 9.2 in GB/T 5080.1.

5.12 High temperature working test

High temperature test shall be conducted in accordance with relevant specifications of

GB/T 2423.2.AC power supply to be tested shall be at connection state for 2

continuous hours with a severity level of highest working environmental temperature.

5.16 Damp heat test

5.16.1 Damp heat test below mine shall be carried out according to relevant

specifications of GB/T 2423.4, severity level is +40°C, and period is 12 d.

Measurement and voltage withstand test of insulation resistance shall be carried out

in 2 h before completion of test (at stage of low temperature with high humidity). After

test, main technical parameters and main functions shall be inspected.

5.17 Vibration test

Vibration test shall be carried out in accordance with GB/T 2423.10, severity level

shall be in accordance with the specifications of Table 6.

6.1 Inspection rules

Inspection consists of factory-exit inspection and type inspection.

6.2 Factory-exit inspection

6.2.1 AC power supply shall be carried out for factory-exit inspection. Qualified

products shall be given certificate.

6.3 Type inspection

6.3.1 Type inspection shall be carried out when one of the following circumstances

occurs.

6.3.2 Inspection items shall be in accordance with the specifications of Table 8.

6.3.5 When batch number is more than 50, sampling inspection shall be carried out

according to GB/T 2829-2002.Choose one-time sampling scheme; judgment level is

III; rejectable quality level (RQL) is not more than 40.Specified RQL of A item is

usually below that of B item; specified RQL of C item is usually more than that of B

item. For type A item, if one-item is unqualified, then the whole batch is judged as

unqualified products, for B- and C-item, unqualified quantities determined shall be in

accordance with relevant standards.

7.1 Marking

7.1.1 Product marks

7.1.1.1 Explosion-proof-type AC power supply shall have MA safety mark.

7.1.2 Packaging marks

7.1.2.1 Mark of packaging, storage and transportation shall be in accordance with the

specifications of GB/T 191.

7.1.2.2 Characters and marks written in external packing box shall at least include.

7.2 Packaging

7.2.1 Packaging pattern of AC power supply shall be in accordance with the relevant

specifications of nation and industries, and shall be specified clearly in relevant

standards.

7.2.2 Accompanying documents shall include.

7.3 Transportation

Avoiding rain and snow, AC power supply after packaging is suitable for various

transportation modes such as water transportation, land transportation and air

transportation.

MT/T 1078-2008

MT

COAL INDUSTRY STANDARD OF

THE PEOPLE'S REPUBLIC OF CHINA

ICS 73.100.99

D 98

File No.. 25344-2008

Direct current power supply with intrinsically

safe output for a coal mine

Issued on. NOVEMBER 19, 2008

Implemented on. JANUARY 01, 2009

Issued by. State Work Safety Administration

Table of Contents

Foreword... 3

3.1 Model

Model of product shall be in accordance with the specifications of MT/T 286.

3.2 Classification

3.2.1 According to explosion proof type.

3.2.2 According to operating principle.

3.2.3 According to output function.

4.1 General requirements

DC power supply shall meet the requirements of this Standard, MT/T 1004, AQ 6201,

etc., and shall be produced according to drawing and technical documents approved

by specified procedure.

4.2 Environmental condition

4.3 Rated power supply condition

4.3.1 Source voltage. in accordance with Table 3.

4.3.2 Source frequency. 50 Hz, permissible deviation is ± 5%.

4.3.3 Harmonic wave. not more than 10%.

4.4 Main technical parameters

4.4.1 AC rated input voltage

AC rated input voltage shall meet input of 127 V and 220 V, it can also be chosen from

4.5 Main functions

4.5.1 It shall have input and output power supply indication function.

4.5.2 It shall have current-limiting, voltage limiting and short circuit protection function,

thus automatic recovery can be made after fault is removed.

4.5.3 AC power supply with standby battery.

4.6 Structure

4.6.1 Fasteners shall have measures that avoid automatic loose.

4.8 Protective function of enclosure

Protective function of enclosure shall be in accordance with GB 3836.1 ~ GB 3836.4,

GB 3836.9, GB 12173 and other relevant standards.

4.9 Electric safety

4.9.1 Insulation resistance between circuit with power of DC power supply and

grounding (or enclosure) shall be in accordance with Table 4.Measurement locations

shall be specified in relevant standards.

4.14.4 AC power supply shall pass storage in low temperature working test; the main

technical parameters, functions and appearance shall not be below requirements of

this Standard.

4.15 Explosion-proof performance

AC power supply of explosion proof type shall be in accordance with the relevant

specifications of GB 3836.1 ~ GB 3836.4 and GB 3836.9, which shall have dual or

multiple current-limiting, voltage limiting and circuit protection function.

4.16 Performance of mining general type

Performance of mining general type shall be in accordance with the specifications of

GB 12173.

4.17 Intrinsically safe parameters

4.17.1 The highest output voltage shall meet requirements of intrinsically safe

explosion proof and shall be specified in relevant standards.

4.17.2 Maximum output current shall meet requirements of intrinsically safe explosion

proof and shall be specified in relevant standards.

5.1 Environmental conditions

Unless otherwise specified in environmental test and relevant standards, test shall be

conducted in the following environmental conditions.

5.2 Main technical parameters and main function test

5.2.1 Measuring apparatus and equipment

5.2.1.1 General requirements for measuring apparatus and equipment

5.2.1.2.3 Artificial load. Adjust the artificial load to obtain load current, maximum

output current and circuit current that are needed by AC power supply output test.

5.2.1.2.4 Voltage regulator. it shall be in accordance with requirements of relevant

standards.

5.2.1.2.5 Oscilloscope, storage oscilloscope and video milli-voltmeter. it shall meet

requirements of relevant standards.

5.2.2 Test circuit

Connect test equipment according to figure 1, S1 and S2 in figure are single-phase

switches.

Figure 1 Test circuit

5.2.3 Test steps

5.2.3.5 Current limiting and short circuit protection function

SET source voltage as specified maximum value, ADJUST artificial load to make load

current gradually increase to output short circuit. OBSERVE ampere meter (A), the

maximum current is maximum output current of AC power supply, final indicating

value is short circuit current of AC power supply. REMOVE over-current and

short-circuit faults, INSPECT whether AC power supply can recover by itself or not.

CARRY out test for 5 times continuously.

For multi-circuit output AC power supply, output of other circuits shall be rated load.

5.4 Appearance inspection

ADOPT visual inspection.

5.5 Enclosure protective performance inspection

Enclosure protective performance inspection shall be conducted in accordance with

the relevant specifications of GB 4208.

5.6 Measurement of insulation resistance

Measurement of insulation resistance shall be conducted in accordance with the

relevant specifications of MT 210.

5.10 Anti-interference test

Anti-interference test shall be conducted in accordance with the specifications of GB/T

17626.3-2006, GB/T 17626.4-1998 and GB/T 17626.5-1999.

5.11 Reliability test

Reliability test shall be conducted in accordance with the relevant specifications of

GB/T 5080.7, ADOPT fixed time test plan. Failure judgment shall be conducted in

accordance with the relevant specifications of 9.2 in GB/T 5080.1.

5.12 High temperature working test

High temperature test shall be conducted in accordance with relevant specifications of

GB/T 2423.2.AC power supply to be tested shall be at connection state for 2

continuous hours with a severity level of highest working environmental temperature.

5.16 Damp heat test

5.16.1 Damp heat test below mine shall be carried out according to relevant

specifications of GB/T 2423.4, severity level is +40°C, and period is 12 d.

Measurement and voltage withstand test of insulation resistance shall be carried out

in 2 h before completion of test (at stage of low temperature with high humidity). After

test, main technical parameters and main functions shall be inspected.

5.17 Vibration test

Vibration test shall be carried out in accordance with GB/T 2423.10, severity level

shall be in accordance with the specifications of Table 6.

6.1 Inspection rules

Inspection consists of factory-exit inspection and type inspection.

6.2 Factory-exit inspection

6.2.1 AC power supply shall be carried out for factory-exit inspection. Qualified

products shall be given certificate.

6.3 Type inspection

6.3.1 Type inspection shall be carried out when one of the following circumstances

occurs.

6.3.2 Inspection items shall be in accordance with the specifications of Table 8.

6.3.5 When batch number is more than 50, sampling inspection shall be carried out

according to GB/T 2829-2002.Choose one-time sampling scheme; judgment level is

III; rejectable quality level (RQL) is not more than 40.Specified RQL of A item is

usually below that of B item; specified RQL of C item is usually more than that of B

item. For type A item, if one-item is unqualified, then the whole batch is judged as

unqualified products, for B- and C-item, unqualified quantities determined shall be in

accordance with relevant standards.

7.1 Marking

7.1.1 Product marks

7.1.1.1 Explosion-proof-type AC power supply shall have MA safety mark.

7.1.2 Packaging marks

7.1.2.1 Mark of packaging, storage and transportation shall be in accordance with the

specifications of GB/T 191.

7.1.2.2 Characters and marks written in external packing box shall at least include.

7.2 Packaging

7.2.1 Packaging pattern of AC power supply shall be in accordance with the relevant

specifications of nation and industries, and shall be specified clearly in relevant

standards.

7.2.2 Accompanying documents shall include.

7.3 Transportation

Avoiding rain and snow, AC power supply after packaging is suitable for various

transportation modes such as water transportation, land transportation and air

transportation.

......