The Ex td a21 designation classifies it as either Class II, Category B, or C for explosion-proof standards.
Explosion Proof Type | Gas Explosion-proof Symbol | Dust Explosion-proof Symbol |
---|---|---|
Intrinsically Safe Type | Intrinsically Safe Type | ia,ib,ic,iD |
Exm | ma,mb,mc | ma,mb,mc,mD |
Barotropic Type | px,py,pz,pxb,pyb,pzc | p;pb,pc,pD |
Increased Safety Type | e,eb | / |
Flameproof Type | d,db | / |
Oil Immersed Type | O | / |
Sand Filled Mold | q,qb | / |
N-type | nA,nC,nL,nR,nAc,nCc,nLc,nRo | / |
Special Type | S | / |
Shell Protection Type | / | ta,tb,tc,tD |
Ex: Signifies that the electrical equipment meets one or more explosion protection types outlined in China’s GB3836 standards, making it appropriate for environments with explosive hazards.
td: This represents protection through the use of an enclosure.
a21: Specifies Class A electrical equipment designed for Zone 21 dust explosion settings.