FLOWPULSE INSTRUCTION MANUAL
62
Flow reading under no-flow condition
POSSIBLE CAUSES
ACTION
Strong vibration on pipe
Reduce the “Sensitivity” setting. Reinstall away
from vibration source.
Local electrical noise
Ensure screen cable is used, and the screen is
not connected to the ground of the power
supply or mA output. The cable screen should
be connected to the enclosure using the cable
entry gland and Earthed on the other end. If
RS485 is used, the cable screen should be
connected to the RS485 screen terminal and the
FlowPulse enclosure separately Earthed if
possible.
Variable Speed Drive (VSD)
interference
Ensure that VSD manufacturers wiring and
grounding instruction is followed.
Reinstall device and cabling away from VSD and
isolate power supply.
Contact with external flowing
liquid
Clad the device and pipe vicinity with porous or
air filled material (i.e. similar to bubble wrap) to
prevent ultrasonic signal from reaching external
flowing liquid.
Flow reading fluctuates or is erratic
POSSIBLE CAUSES
ACTION
Device installed too close to
valve, pump, tees, or elbows.
Non-return valves can produce
strong knocking.
Reinstall further away if possible.
Increase the “Damping” setting on the
device.
Turn “Step Response” off if necessary.
Use a smaller “Step Limit” if fluctuation persists.
The response time will increase with such
settings.
