YOKOGAWA FVX110, User Manual

Page: 24 / 168

<2. Handling Cautions>
2-13
IM 01S01C01-01EN
Note 4. Maintenance and Repair
• The instrument modification or parts
replacement by other than authorized
representative of Yokogawa Electric
Corporation is prohibited and will void
DEKRA Intrinsically safe Certification.
Note 5. Special Conditions for Safe Use
• In the case where the enclosure of the
segment indicator is made of aluminium, if
it is mounted in an area where the use of
category 1 G apparatus is required, it must
be installed such, that even in the event of
rare incidents, ignition sources due to impact
and friction sparks are excluded.
Note 6. Installation instructions
• The test voltage for the isolation between the
intrincically safe supply/output circuit and the
frame of the apparatas for segment indicator
that are provided with surge protection is
limited to 90 V, due to the presence of the
surge protection device only.
When used in a potentially explosive
atmosphere, requiring the use of apparatus
of equipment category 1D or 2D, certified
cable entry devices shall be used that are
suitable for the application and correctly
installed.
● FISCO Model
Non-Hazardous
Locations
Hazardous Locations
F0209.ai
Terminator
(FISCO Model)
Ex i
Field Instruments
(Passive)
Hand-
held-
Terminal
Supply Unit and
Safety Barrier
(FISCO Model)
Terminator
Data
U
U
I
I.S. fieldbus system complying with FISCO
The criterion for such interconnection is that the
voltage (Ui), the current (Ii) and the power (Pi),
which intrinsically safe apparatus can receive,
must be equal or greater than the voltage (Uo),
the current (Io) and the power (Po) which can be
provided by the associated apparatus (supply unit).
Po ≤ Pi, Uo ≤ Ui, Io ≤ Ii
In addition, the maximum unprotected residual
capacitance (Ci) and inductance (Li) of each
apparatus (other than the terminators) connected
to the fieldbus line must be equal or less than 5 nF
and 10 µH respectively.
Ci ≤ 5 nF, Li ≤ 10 µH
Supply unit
The supply unit must be certified by a Notified
body as FISCO model and following trapezoidal or
rectangular output characteristic is used.
Uo = 14...17.5 V (I.S. maximum value)
Io based on spark test result or other assessment,
No specification of Lo and Co is required on the
certificate or label.
Cable
The cable used to interconnect the devices needs
to comply with the following parameters:
Loop resistance Rc: 15...150 Ω/km
Inductance per unit length Lc: 0.4...1 mH/km
Capacitance per unit length Cc: 45...200 nF/km
Length of spur cable: max. 60 m (IIC and IIB)
Length of trunk cable: max. 1 km (IIC) or 5 km
(IIB)
Terminators
The terminator must be certified by a Notified body
as FISCO model and at each end of the trunk
cable an approved line terminator with the following
parameters is suitable:
R = 90 . . . 102 Ω
C = 0 . . . 2.2 µF. (0.8...1.2 µF is required in
operation)
The resistor must be infallible according to IEC
60079-11.
Number of Devices
The number of devices (max. 32) possible on a
fieldbus link depends on factors such as the power
consumption of each device, the type of cable used,
use of repeaters, etc.