EX100/200 SERIES INSTRUCTIONS
Seametrics • 253.872.0284
Page 11 seametrics.com
Grounding Guidelines:
For best results, use a good quality earth ground, such as
metallic water piping or a driven ground, to ensure a good
connection to earth ground and good noise suppression.
If the flow sensor is installed in metallic piping, for optimum
connection clamp wire to the piping a short distance to one
side of the flow sensor using an electrical grounding clamp.
Connect the wire to the earth ground and to one of the
housing screws.
For Non-Metallic Pipe:
Connect one to the housing
screws by wire to a good earth ground, such as metalic
water piping or a rod driven into the ground.
EX meters are usually unaffected by moderate levels of
electrical noise. In some applications performance may be
improved by taking the following steps:
• Use shielded twisted pair cable (Belden 8723 or
equivalent above ground or Alpha 35482 or equivalent
burial).
• Clamp a ferrite bead (Steward 28A2029-OAO or
equivalent) on meter signal/power wire within 3/4”
of the meter strain relief (tape or tie wrap in place if
necessary). See diagram below.
• IMPORTANT - Connect the cable shield ground
wire to ground, ONLY at power supply end of cable.
General Electrical Guidelines
• Whenever possible avoid running control cables in
the same conduit with or bundled with AC power.
• Using shielded cable, be sure to connect shield to
ground at power supply end of the cable. Do not
connect other end of shield.
•
Avoid routing flow sensor cables in close proximity to
a variable frequency drive.
• Recommended power and output wiring is shielded
twisted pair 18-22 AWG control cable.
•
Recommended voltage is 12-24 Vdc. Note that
unregulated power supplies can vary from nameplate
voltage by a considerable amount, especially with AC
line voltage fluctuation. Therefore 24V power supplies
must be regulated.
See the Connections diagrams on the following pages for
the appropriate terminals.
Power
A 12 - 24 Vdc power supply capable of at least 250 mA
current output is needed.
Output
The standard output is pulses with flow in the forward
direction (Reverse flow output is optional [-15] ). Electrically
it is an open collector opto isolated switch. The output is
not internally powered.
Note:
This output is limited to 6 mA at 30 Vdc maximum.
Caution:
The EX100/200-Series have
strong start and run currents. When using
solar panels and VRSLA batteries as a
power source, use caution to insure the EX-
series sensor has the -50 Low-power Option and that
all Seametrics products on the power circuit receive
sufficient voltage and current under all conditions.
Failure to do so will lead to unreliable operation and
possible damage to the unit/s. Please reference
the technical bulletin, ‘Solar and Battery-Power
Guildlines’ available on our website: www.seametrics.
com
ELECTRICAL CONNECTIONS
Earth Ground
Grounding
Clamp
Place Ferrite
Bead Here
Housing Screw
Metallic Pipe
