Kessel SG 400 V Mono Original Operation Manual page 54

Mono/Duo ATEX level sensor
Connect the ends of the level sensor's leads to the terminals [10].
The level sensor's connection is identical for both Mono and Duo systems.
Only connect level sensors that satisfy the ATEX requirement to the
Zener barrier.
54
Overview of connections for the level sensor
Black (minus)
Note: When extending the cable of the level sensor use
KESSEL-junction box (art. No. 28799).
Zener barrier
level sensor
HAZ
bl bl
3 4
(-)
(+)
rt/RD sw/BK
Installation and operating manual
Wire colour Name on Zener barrier
Red (plus) 3
4
Zener barrier Zener barrier
Mono floater Duo floater
HAZ HAZ HAZ HAZ
bl bl bl bl
7 8 7 8 7 8
3 4 3 4 3 4 3 4
(-)
(+) (+)
rt/RD sw/BK rt/RD
Convert floater to level sensor
7
8
(-)
sw/BK
[10]
010-532_05