Page 242 - Electrical Installation in Hazardous Area

206 Electrical installations in hazardous areas

A 0

SWITCH UNIT
TYPE TB 51
SERIAL NO 12345

EExde I1 T4 (Ta = -10 to +50"C)

E FGH J
A = Manufacturers logo for identification
B = Apparatus description and type no.
C = Apparatus serial or batch no.
D = Certification Code: note dual protection (EExd) switch with EEx e
connection facilities; Ta, ambient temperature range.
Marked only because it is not the normal
one used by the Standard.
E = Identification of the certification body (test house)
F = Year of issue of certificate
G = Identification of Principal Protection Concept
H = Number of certificate within that year
J = X indicating special conditions for safe use (certificate must be
consulted for these)

Fig. 8.8 Example of apparatus marking

A
I X I
I G. WITHERSPOON PIC
RELAYTY ERLI

A = Manufacturers name
B = Manufacturers type no. (note serial no. not necessary)
C = Certification Code (note no temperature classification)
D = Certification body identification logo
E = Year of certificate issue
F = Identification of Principal Protection Concept
G = Number of certificate in year
H = U indicates a component
Fig. 8.9 Example of component labelling

Additional marking

In some cases, such as pressurization 'p' it is necessary to provide addi-
tional information, such as the purge rate and time necessary to ensure
that the user is aware of the settings which must be applied to the control