KROHNE H250 M10 ATEX II2G Ex d EN - Manual (Page 11)

ELECTRICAL CONNECTIONS
4
11
H250 M10
www.krohne.com 06/2012 - 4001058901- MA H250/M10-Ex-II2G-AD R02 en
4.3 Inputs / outputs
The signal circuits of the variable area flowmeter may only be connected to downstream devices
or circuits that satisfy the requirements of protective extra-low voltage (PELV).
Connecting power and I/O functions
• Before connecting or disconnecting the electrical connection cables of the device, make sure
that all cables leading to the converter are isolated from the ground of the hazardous area.
This also applies to protective ground (PE) and equipotential bonding conductors (PA).
• All connecting cable conductors and shields that are not securely connected to the
equipotential grounding system of the hazardous area shall be carefully isolated from one
another and from ground (1500Vrms test voltage for non-intrinsically safe cables)
• Connect all shields by the shortest route possible to the press fitted U-clamp (PE) terminal
located in the terminal compartment. If shields are to be grounded at both ends (e.g., for EMC
reasons), adequate equipotential bonding is required between the two shields to avoid
unacceptable equalizing currents.
• The converter shall be incorporated into the equipotential bonding system of the hazardous
area. Connect the conductor to the press-fitted U-clamp mounted on the outside of the
converter housing.
• The measuring tube can be incorporated into the equipotential bonding system of the
hazardous area using the U-clamp mounted on the flange if present, or suitable conductive
connections (seals, etc.).
Terminal assignment
Function - signal output Terminal designation
Current output HART ® (current loop) I+ I-
Status output (1)
(Binary output 1)
NAMUR B+ B
N
O/C-PNP B+ B
OC
Status output (2)
(Binary output 2)
NAMUR B+ B
N
O/C-PNP B+ B
OC
Status input (reset counter) R+ R-
Figure 4-1: Indicator M10 terminal connection
1 Power supply - analog output
2 Switching output B1
3 Switching output B2 or pulse output
4 Reset input R
AD_H250_M10_II2G_R02_en_058901_PRT.book Page 11 Tuesday, June 26, 2012 7:20 AM