Figure 2: Typical Levelmaster Configuration For General-Purpose Locations; Figure 3: Levelmaster Configuration Example For A Hazardous Location - ABB LevelMaster 7100 User Manual

LAST SENSOR
ON RS-485 BUS
(MUST BE TERMINATED )
Hazardous location installation (with barrier board)
The LevelMaster installation in a hazardous location consists of a single or multiple LevelMasters (on an RS-485 bus) connected
to a host controller through an intrinsically safe barrier board (Figure 3). No direct connection to the LevelMaster(s) is allowed in
the hazardous area. Connecting a laptop for local monitoring or data retrieval should also be done through the barrier.
Power the LevelMaster from the host controller or from an external power supply. If using an external power supply, connection
must also be done through the barrrier.
LAST SENSOR
ON RS-485 BUS
(MUST BE TERMINATED )
Installation with optional high level auxiliary switch
The high level auxiliary switch is an optional component for installation. This additional switch can be installed with the
LevelMaster to function as an auxiliary shutdown switch. The switch is a float-type switch that can be configured in the field to
function as normally open or normally closed. The switch comes in four configurations based on the distance from the top of the
tank to the float switch location: 12, 16, 24 and 36 inch. Figure 4 shows the 12-inch switch assembly.
LevelMaster 7100 User manual 2105835 Rev AA | 8
RS-485
VDC PWR

Figure 2: Typical LevelMaster configuration for general-purpose locations

HAZARDOUS AREA
CLASS I, DIV 1, GROUP D
FIRST OR INTERMEDIATE SENSOR
RS-485
VDC PWR

Figure 3: LevelMaster configuration example for a hazardous location

FIRST OR INTERMEDIATE SENSOR
ON RS-485 BUS
(NOT TERMINATED)
ON RS-485 BUS
(NOT TERMINATED)
HOST
CONTROLLER
RS-485
VDC PWR
BARRIER
BOARD
RS-485
VDC PWR
HOST
CONTROLLER
NON-HAZARDOUS AREA