Flameproof Material Standards All Flameproof Electrical Equipment's are Designed and Constructed in Accordance with following Standards:-
àIS 2148-1981
àIEC 60079-1
àIS 13346-1992
SELECTION OF ELECTRICAL EQUIPMENT :-
A
No. of Logical steps are involved in selection of Electrical Equipment for
Hazardous Area:-
Step 1:- Identify its Gas Group & Temperature
Class
Step 2:- Identify the Zone Area Zone 0, 1 or 2
Step 3:- Select the type of
Protection Appropriate to the Zone
Step 4:- For the given type of
protection select the equipment keeping in Mind the Gas Group and Temperature
rating.
Step 5:- Depending upon whether the Equipment to
be installed indoor or Outdoor ensure the correct IP for the equipment
GUIDE TO CERTIFICATION
CODE:-
Apparatus Marking normally include a
certification code which include the following:-
Symbol
for the type of protection. The apparatus group. The Temperature classification
Example:- Ex ‘d’ IIB T5 This
indicates a unit having Flameproof protection of type ‘d’ Suitable for gas
group IIA & IIB and having maximum temp. classification of 100 deg. Cel.
As
per (T5) Some construction features of this flame proof AC motors are as
follows :-
1.
The flame proof construction for Exd.
2.
The degree of protection is IP 55 for motor main enclosures.
3.
The stator winding are of class F insulation and gives a large margin of safety
in temperature rise and long service life.
4.
The stator winding insulation is good in electrical and mechanical properties,
moisture resistance and thermal stability.
5.
A cylindrical shaft extension is furnished on motors that can be driven by
coupling or spur gearing
6.
The rotors are of cast- aluminum and dynamically balanced to make the motor
operate smoothly with small vibration and the low noise.
7.
Fans are made of cast iron, and have low windage loss.
8.
The stator and rotor cores are laminated with high class electrical steel with
high permeability and the low loss
