KROHNE OPTIWAVE 7300 IECEx - Manual (Page 15)

ELECTRICAL CONNECTIONS
3
15
OPTIWAVE 7300 C
www.krohne.com 10/2010 - 4000176502 - AD IECEX OPTIWAVE7300 R02 en
3.6 Ex d[ia] / Ex tD[iaD] equipment
3.6.1 General notes
Ex d[ia]- and Ex tD[iaD]-approved equipment have two separate compartments. The electronics
in the electronics block compartment are Ex ia / ExiaD-approved and the terminals
compartment is Ex d / Ex tD-approved.
3.6.2 How to connect the electrical cables
Cable entries are supplied on customer demand. If you supply the cable entries, this part must
have a degree of ingress protection IP≥6x (IEC 60529).
Load resistor
• Connect the load resistor to the positive terminal of the power supply
• Ground the negative connection.
• If the load resistor has to be connected to the negative terminal, the loop resistance must not
be more than 250 ohms.
Figure 3-3: Compartments in Ex d[ia]- and Ex tD[iaD]-approved equipment
1 Electronics block (Ex ia / Ex iaD) compartment
2 Terminal (Ex d / Ex tD) compartment
INFORMATION!
If you must open the electronics block compartment and remove the electronics blocks for
servicing, it is not necessary to disconnect the wires from the Ex d / Ex tD terminal.
INFORMATION!
The flamepath dimensions are better than the values specified in the International Standard
IEC 60079-1 (minimum length 14.5 mm and maximum gap 118
µ
m).
WARNING!
Use only Ex d-approved cable entries and plugs for Ex d applications. Use only Ex tD-approved
cable entries and plugs for Ex tD applications.