These can be used in hazardous atmospheres like in Coal mines, Oil rigs/mines, Refineries, Chemical Plants
INTRODUCTION
Hazardous areas are defined as those locations where explosive gas-air mixture may occur in dangerous concentrations and are defined in accordance to Indian Standard IS: 5572. The general classification is as highlighted in the following table:
Zone
| Classification of Area as per IS: 5572
| Use of Electrical Equipment
|
|---|
Zone “0”
| Area in which hazardous atmosphere is continuously present
| Use of Motors is to be avoided as far as possible or use intrinsically safe or pressurized electrical equipment.
|
Zone “1”
| Area in which hazardous atmosphere is likely to be present at any time under normal operating conditions.
| Flameproof motors with type Ex “d” as specified in IS /IEC: 60079-1.
|
Zone “2”
| Area in which hazardous atmosphere is likely to be present only under abnormal operating conditions & for a short period.
| Motors with all electrical contacts to be enclosed in flameproof enclosure and conform to IS: 6381 and designated as Type “e” or Type “n”.
|
Customers are to select the motor type depending on the type of area of operation of the motors and should generally follow the guidelines given above in conjunction with the relevant Indian Standards specified above.
CLASSIFICATION of HAZARDOUS GASES:
Hazardous gases have been classified in IS/IEC: 60079-0 and IS: 5572 are associated with only flameproof motors as listed below:
Note: FLP Motors are offered suitable for Gas Groups IIA and IIB only. Any other gas not specified in the below table, one has to refer relevant IS for the motor selection.
GROUP OF ENCLOSURES SUITABLE FOR PARTICULAR FLAMMABLE GAS OR VAPOUR AS PER IS: IS/IEC 60079-0
Group of Enclosure
| Gas or Vapour
|
|---|
I
| Methane (firedamp)
|
IIA
| Ammonia
| Pentane
| Xylene
| n-Propyl acetate
| Iso-butanol
|
| Industrial methane*
| Hexane
| Cyclohexene
| n-Butyl acetate
| n-Butanol
|
| Blast furnace gas
| Heptane
| Acetone
| Amyl acetate
| Amyl alcohol
|
| Carbon monoxide
| Iso-octane
| Ethyl methyl ketone
| Chloro-ethylene
| Ethyl nitrate
|
| Propane
| Decane
| Methyl acetate
| Methanol
|
|
| Butane
| Benzene
| Ethyl acetate
| Ethanol
|
|
IIB
| 1,3-Butadiene
| Diethyl ether
| Ethylene oxide
| Town gas**
| Ethylene
|
IIC
| Hydrogen
|
* Industrial methane includes methane mixed with not more than 10% by volume of hydrogen.
** Town gas may contain no more than 57% by volume of hydrogen & not more than 16% by volume of carbon monoxide. The remainder being the mixture of paraffin hydrocarbons & inert gas.
PAINT & FINISH:
All motors are given special treatment of primer & paint to internal as well as external surfaces. All external surfaces are coated with epoxy polyamide base acid/alkali resistant paint of RAL shade 7046.
TERMINAL BOX LOCATION:
Flameproof motors have terminal box on the top as standard.
