KROHNE VARIFLUX IFS 6000 F-EEx EN - Manual (Page 9)

ALTOFLUX IFS 4000F-EEx, PROFIFLUX IFS 5000F-EEx, VARIFLUX IFS 6000F-EEx 9
1.3.1 Mechanical construction
The IFS 6000 F-EEx primary head is the measuring unit of the flowmetering system (see block
diagram in section 1.4). It contains two field coils and two electrodes in type of protection intrinsic
safety category "ib" according to EN 50020. The type of protection of the field coils depends on the
meter size:
DN2.5…DN15 Encapsulation
“m” according to EN 50028 and
Increased safety “e” according to EN 50019
DN25…DN150 Flameproof enclosure “d” according to EN 50018
The electrode circuits are wired by separate shielded cables and marked by the sheath color (white
and purple). The intrinsical safe "EEx ib" electrode circuits inside the IFS 6000 F-EEx primary head
have the following maximum values (entity parameters):
Maximum input voltage
U
max
= 20 V
Maximum input current I
max
= 170 mA
Maximum internal capacitance C
i
= 0
Maximum internal inductance L
i
= 0
The two field coils inside the primary head are connected in series and have a maximum resistance
of 85
Ω per coil with a wire diameter of at least 0.25 mm and insulation class H (T
max
≥ 180°C)
according to IEC 85. The field coils are supplied with a square-wave signal with a voltage of ± 40 V
and a nominal current of 125 mA. The coil circuit is protected by two 160 mA series fuses, which are
installed inside the associated signal converter unit (e.g. IFC 090 F/…-EEx).
1.3.2 Data plates of VARIFLUX IFS 6000 F-EEx
Data plate 1 Data plate 2