KROHNE M10 Converter H250-H 54 Ex II2G EN - Manual (Page 7)

11/2002
Signal converter M10-EEx d – Supplementary instructions 7
5.1 Electrical connection
5.1.1 General
Insulation rating
The insulation of variable-area flowmeters H..../..../M10 - EEx is rated in conformity with
VDE 0110-1/04.97, equivalent to IEC 60 664-1, and takes into account the following ratings:
•
Overvoltage category for signalling and measurement circuits: II
• Insulation contamination level: 2
HAZARDOUS-DUTY Systems
•
The signal converter to be incorporated in the equipotential bonding system via the external
PA (equipotential bonding) connection.
• The electrical connection of the variable-area flowmeters to be made as a fixed installation.
5.1.2 Terminal compartment
The electrical connection of the power supply and I/O functions is made in the integrated terminal
compartment of the signal converter. The terminal compartment is designed in EEx d type of
protection. Unassigned openings to be sealed in conformity with EN 50 018.
The cables can basically be routed into the flameproof terminal compartment in one of two ways.
• Direct entry of the connecting cables by way of certified flameproof cable glands into the
flameproof terminal compartment (V
≤ 2000 cm³). The cable glands must possess a separate
test certificate to EN 50 018. The requirements specified in the test certificate for the cable
gland need to be observed.
• Direct entry of the power cables by way of conduits into the flameproof terminal compartment
of the device. After the conduit has been screwed in, this must together with the housing form
a flameproof joint with a minimum of 8mm depth of engagement. A suitable stopping box shall
be provided in accordance with the regulations for electrical installations. Installation of the
conduit must be carried out in compliance with its separate test certificate.
5.1.3 Connecting cables
The connecting cables shall be selected in keeping with the valid installation standards
(e.g. EN 60079-14 / VDE 0165). The outside diameter of the cables must match the cable
clamping area for the cable entries.
5.1.4 Connection of power and I/O function
• Before connecting or disconnecting the electrical interconnecting cables of the device, make
sure that all cables leading to the signal converter are isolated from the ground (reference
potential) of the hazardous area. This also applies to safety conductors (PE) and equipotential
bonding conductors (PA).
• All cores and shields of the connecting cables not safety-connected to the equipotential
bonding system for the hazardous area should be carefully insulated from each other and
from ground (test voltage 1500V
rms
for conductors of non-intrinsically safe cables).