Flomec 490, Instruction Manual

Page: 9 / 20

Electrical connections 8
3.2 Optional
– NPN Hall Reed Switch outputs
3.3 Optional - Reed switch only
HAZARDOUS AREAS
The REED SWITCH output is classed as a
“simple apparatus“ as defined in the
CENELEC
standard EN50020 &
recognized IEC & ATEX directive. It can
be connected
to an approved I.S.
secondary instrument with both being
located in the hazardous area.
The Reed Switch may also be connected
through an approved I.S. barrier.
Note: The Reed switch produces 1/3
rd
the normal pulse output value
( eg. 1/3 the standard K-factor )
Conductor color coding also applies to the Non-magnetic
sensor and high temperature output options
A1
A2
B2 B1
b1
REED SWITCH OUTPUT
Screen
Yellow
Green
SQUARE WAVE OUTPUT
Red ( VDC supply )
White ( + Sig. output )
Black ( -0v ground )
T
erminal box option
terminal connections
Pull up resistor
required, they are
generally incorporated
in most receiving
instruments
Hex adaptor
Rotor
Body
Positioning
collar
Height
adjustment
nuts
1.5” or 2” BSPT
or NPT
LOCK
To -0V
Screen
Yellow
Green
LOCK
REED SWITCH
OUTPUT