What is the intrinsic safety type?

The explosion-proof type is mainly by limiting the various parameters of the electrical equipment circuit, or taking protective measures to limit the spark discharge energy and heat energy of the circuit, so that the electrical spark and thermal effect generated under the normal operation and the specified fault state can not ignite the explosive mixture of the surrounding environment, so as to achieve electrical explosion-proof, the electrical equipment circuit itself has explosion-proof performance. That is, from “ Essence ” The above is safe, so it is called intrinsically safe. Electrical equipment using intrinsic safety circuit is called intrinsically safe electrical equipment.

So through the above we understand what is the safety type, then explosion-proof products need to do what testing and certification? The following Deli innovation for you to explain what explosion-proof products need to do certification.

First, explosion-proof mark

The explosion-proof mark is used to describe the explosion-proof grade, temperature group, explosion-proof type and the applicable area of the explosion-proof electrical equipment. Explosion-proof equipment enclosures must be marked with permanent explosion-proof identification Ex.

1. Composition of explosion-proof mark

According to the requirements of GB3836 standard, the explosion-proof mark of explosion-proof electrical equipment includes: explosion-proof mark + explosion-proof structure type + explosion-proof equipment category + (gas group) + temperature group + equipment protection level

1) explosion-proof identification

Ex indicates that the product is explosion-proof electrical equipment.

2) explosion-proof structure type

The structural forms of explosion-proof electrical equipment are:

d indicates flameproof type;

e represents increased safety type;

i indicates intrinsically safe type, divided into ia and ib;

p stands for positive pressure type;

o stands for oil-immersed type;

q stands for sand filling type;

n indicates no spark type;

m stands for casting type;

s stands for explosion-proof special type.

3) explosion-proof equipment category

That is, the category of dangerous places for explosion-proof electrical equipment.

(1) Ⅰ indicates the coal mine environment, and Class I electrical equipment is used in coal mines.

Class II electrical equipment is used in all other explosive gas environments except underground coal mines. Class IIA represents propane, Class IIB represents ethylene, and Class IIC represents hydrogen.

Class II devices are classified according to the maximum test safety gap MESG (mm, flameproof type) or the minimum ignition current ratio MICR (the ratio of the minimum ignition current of the corresponding gas to the minimum ignition current of methane, intrinsically safe type).

IIA: MESG≥ 0.9; MICR > 0.8

IIB: 0.9 > MESG > 0.5; 0.8 & ge; MICR≥ 0.45

IIC: 0.5≥ MESG; 0.45 > MICR

IIB equipment can be used for IIA equipment conditions of use, and IIC equipment can be used for IIA and IIB equipment conditions of use.

(3) lll means dust environment, Class III electrical equipment is used for explosive dust environment other than coal mine. Class IIIA is combustible floc, Class IIIB is non-conductive dust, and Class IIIC is conductive dust.

Devices marked IIIB may be used under the conditions of use of IIIA devices, and devices marked IIIC may be used under the conditions of use of IIIA and IIIB devices.

4) Gas group

The detonation ability of explosive gas mixture marks the level of its explosion danger, and the greater the detonation ability of explosive mixture, the higher the risk. The detonation capacity of an explosive mixture can be expressed by the maximum test safety gap. At the same time, the difficulty of explosive gas, liquid vapor and mist being ignited also marks the level of its explosion risk, which is expressed by the minimum ignition current ratio. Class II flameproof electrical equipment or intrinsically safe electrical equipment is further classified into classes IIA, IIB and IIC according to its maximum test safety clearance or minimum ignition current ratio for explosive gas mixtures.

5) Temperature group

That is, the maximum allowable value group for the surface temperature of explosion-proof electrical equipment. It is divided into T1-T6 groups, so that the maximum surface temperature of the electrical equipment in the corresponding T1-T6 group cannot exceed the allowable value of the corresponding temperature group.

The relationship between temperature groups, equipment surface temperature (° C) and ignition temperature T (° C) of combustible gases or vapors is as follows:

T1:450; T > 450

T2:300; 450≥ T > 300

T3:200; 300≥ T > 200

T4:135; 200≥ T > 135

T5:100; 135≥ T > 100

T6:85; 100≥ T > 85

6) Device protection level EPL

According to the possibility of the equipment becoming the ignition source and the different characteristics of the explosive gas environment, explosive dust environment and coal mine methane explosive environment, the protection level of the equipment is specified.

(1) The protection level of underground coal mine equipment is divided into Ma and Mb;

(2) The protection level of electrical equipment for explosive gas environments other than coal mines is divided into Ga, Gb and Gc;

(3) The protection level of electrical equipment for combustible dust environments other than coal mines is divided into Da, Db and Dc.

2. Explosion-proof mark of Class I explosion-proof electrical equipment

Ex + Explosion-proof type + Category (I)+Ma/Mb

Explosion-proof structure types include: d, e, ia, ib, ma, mb, px, q

3. Explosion-proof mark of Class II explosion-proof electrical equipment

Ex + explosion-proof type + Class (Ⅱ)+ Class (A/B/C)+ Temperature group (T1 ~ T6)+Ga/Gb/Gc

Explosion-proof structure types include: d, e, ia, ib, ic, ma, mb, mc, nA, nC, nR, (nL), o, px, py, pz, q

4. Explosion-proof mark of Class III explosion-proof electrical equipment

Ex + explosion-proof type + area where the equipment can be used (A or B before the tD type area)+ housing protection class (IP code)+ maximum surface temperature T, temperature value can be measured + maximum surface temperature TL(T- temperature value /L- dust layer thickness; Maximum surface temperature in excess of 50mm thick dust layer; Or symbol “ X”)

Explosion-proof structure types include: tD, pD, iaD, ibD, maD, mbD

Second, explosion-proof certificate

The complete contents of the explosion-proof certificate include the logo of the certification authority, the certificate number, the manufacturing unit, the product name, the product model specifications, the explosion-proof mark, the inspection standard, the certificate validity period, etc. Take this one, for example:

1. License issuing agency

EETI National electrical products Quality supervision and inspection center.

2. Certificate number

EETI 00.0000X Each certificate has a unique certificate number.

1) The explosion-proof certificate number shall be in the following form: two-digit year, followed by the explosion-proof certificate serial number of the year, consisting of four digits, separated from the year by a ". ". For example, CNEx16.0460 means the 0460th explosion-proof certificate issued by Nanyang Explosion-Proof Institute in 2016. Another example is CE14.1262, which means the 1262 explosion-proof certificate issued by Tianjin Explosion-Proof Institute in 2014.

2) Postscript

The explosion-proof certificate number is sometimes followed by X or U, such as EETI 00.0000X, where X is used to indicate additional special safety conditions or restrictions of the symbol, in this case, the explosion-proof certificate number X indicates that the product must be used together with other explosion-proof products. U is used to represent the symbol of Ex components, that is, this component is only a part of the explosion-proof structure type, can not be used alone, can only be combined with other components or components, in order to become a complete explosion-proof equipment. This component is often a common accessory for manufacturers. For example, U of CE16.1146U indicates that the explosion-proof combustible gas detector housing is only an Ex component and cannot be used alone.

3. Manufacturing units

The holder, Shenzhen Deli Innovation Safety Equipment Co., LTD.

4. Product name

XXXX Monitors the terminal.

5. Model specifications

SG500-N1, DC 3.6V.

6. Explosion-proof mark

Ex d ib II B T5 Gb.

7. Inspection standards

GB3836.1-2010 Explosive atmosphere-Part 1: General Requirements for Equipment;

GB3836.2-2010 "Explosive atmospheres-Part 2: Equipment protected by flameproof enclosures";

GB3836.4-2010 Explosive atmospheres - Part 4: Equipment protected by intrinsically safe “i”

8. Validity period of the certificate

June 16, 2024.

Different certification agencies may also reflect product standards (enterprise standards), final assembly drawing number, drawing number, and main technical parameters on the certificate.