KROHNE OPTIFLUX 2000-4000-5000-6000-7300-IFC 300 Ex EN - Manual (Page 33)

ELECTRICAL CONNECTIONS
4
33
OPTIFLUX
www.krohne.com 07/2010 - 7309482600 - AD EX IFC 300 R06 en
4.2 Connection of IFC 300
The flow sensors and the signal converter in field version must be incorporated in the
equipotential bonding system of the installation. This can be established internally by connection
of the protective earth (PE) conductor of the mains supply system to the internal PE clamp, or
externally, by connecting a separate equipotential bonding conductor to the external U-clamp
terminal (size M5) at respectively the flange of the mounting support (in case of compact
instruments) or at the wall-mounting device (for signal converters in field version). A separate
bonding conductor must have a cross-sectional area of at least 4 mm
2
.
The display cover seals the electronics compartment of the converter housing and provides type
of protection “flameproof enclosure”. The terminal compartment is default in type of protection
“
increased safety” and can optionally be performed as flameproof enclosure. The threaded joints
formed by the covers and housing are a tight fit due to the requirements for type of protection
“
flameproof enclosure”. Screw the covers on and off with care and never use excessive force !
Keep the screw-threads free of dirt and well-greased (e.g. with PTFE grease). The grease will
help to prevent the threads from locking due to corrosion.
To unscrew the covers, first release the interlocking devices (one at each cover). Therefore
unscrew the M4 head screw with internal hexagon socket set using a No. 3 Allen key until the
interlocking device can be turned. After the covers are screwed back onto the housing, make
sure that the interlocking devices are properly refitted.
Data for connection on all Ex e terminals:
stripping lenght for wires: 8 mm, torque for screws: 0.6 - 0.8 Nm.
WARNING!
Allow the electronics to de-energize before opening the electronics compartment of the flow
converter housing. Wait at least 35 minutes for T6 and 10 minutes for T5 before opening.
Figure 4-1: Electrical connections
Terminals Terminals Terminals Terminals Function, electrical data Function, electrical data Function, electrical data Function, electrical data
L, N
L+, L-
Connections for mains supply, always non-Ex i
100...230 V AC, +10%/-15%, 22 VA
12...24 V DC, +30%/-10% (short-time: -25%), 12 W
24 V AC, +10%/-15%, 22 VA
24 V DC, +30%/-25%, 12 W
U
m
= 253 V
A, A-, A+
B, B-
C, C-
D, D-
Connections for signal I/Os (PELV circuits), non-“Ex
i” or “Ex i”, are dependent on the specific version of
the signal converter ordered. Consult the tables
with CG numbers for details.