KROHNE BM 100A Handbook - Manual (Page 17)

Handbook BM 100 A 17
2 Electrical Connections
2.1 Insulation rating
The gauge transmitter electrical insulation conforms to IEC 1010-1. Please note the information
below concerning each rating category.
Category
Rating Comments
Power supply
overvoltage category
III
The gauge does not have an integrated switch or circuit-
breakers. These elements must be installed in
conformance to local regulations and EU Low Voltage
Guidelines and to properly isolate the equipment when
necessary. Note that this is not obligatory for instruments
with 24 V power supply boards.
4 to 6.3 A time lag fuses are recommended for external
installation.
Fuses must be installed on every electrical conductor for
the system to conform to current regulations.
Note that the active phase conductor, L, is protected by an
internal fuse: the neutral conductor, N, is not.
Output circuit overvoltage category II Fuses are unnecessary.
Insulation
contamination level 2
The contamination level refers to the protection of internal
elements of the signal converter.
Rated IP 67 (equivalent to NEMA 6-6P) against ingress of
water and other foreign bodies.
Note that the gauge can operate in contamination level 4
conditions if installed correctly.
Protection class 1
Galvanic isolation of terminals
The gauge conforms to the following standard and E.U. Directive:
Standard/Directive Description
EN (IEC) 61010-1
Safety requirements for electrical equipment for measurement, control and
laboratory use (low tension)
73/23/EEC Council Directive of 19 February 1973 on the harmonisation of the laws of
Member States relating to electrical equipment designed for use within
certain voltage limits (low voltage) modified by Directive 93/68/EEC (art.13).
The BM 100 A gauge outputs are galvanically isolated from the power supply and ground in
accordance with the regulations given above. An external barrier is unnecessary.