Omni Instruments DFS2 User manual

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
INSTRUCTION
MANUAL
DFS2
DOPPLERFLOWSWITCH
(Withrateindicator)
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Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
1
DopplerFlowSwitch-DFS2
Introduction
The Doppler Flow Switch - DFS2measuresthevelocityoffluidsinpipelinesusing
atotallynon-intrusiveprinciple.
NB! It isintendedforusewithsewage,pulps,mining slurries,andotherfluidswhich
containinexcessof 0,1%suspendedsolids orbubbles.Theparticlesizefor
successfuloperation mustbe greaterthan100microns.
The DFS2 enclosureisratedIP65. Theflowswitchincludesarelaywithadjustable
highand lowsetpoint controls,plusdelay-onanddelay-off adjustabletimers.The
DFS2 requires24Vdc,115or230Vacpowersupply.
Twoselectableflowrangesof 0–2m/s,or0–6m/sareavailable,andtheflowrate
isdisplayedonabargraphindicator.
Connections andAdjustments
Removaloftheflowswitchcoverwill revealtheplug-inconnectionsandvarious
adjustments,detailedasfollows:-
Figure1
Lo
Hi
T1
T2
Trip pointadjust
Timeradjust
Lo
Hi
Selectorswitch‘S1’
JP1
1
2
1 2
JP2
Terminal No. Connection
1Live/ Positive
2Neutral/ Negative
3Earth
4RelayN.O
5RelayN.C
6RelayCommon
7To reset contact
8To reset contact
9SensorTx(Yellow)
10 Screen Tx(Green)
11 Screen Rx(White)
12 SensorRx(Brown)
123456789101112
Rangeselection
Latchselection
0-2m/s
0-6m/s
OnOff

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
2
Connections
Sensor : Connect thesensorto the 4-way terminal
plugas indicated inFigure1 TerminalNo’s 9
to 12.
PowerInput :Check that the operating voltage of the flow
switch is correct, (i.e.24Vdc, 115Vac or
230Vac)before connectingthe powersupply.
Relay
:The relay has achangeovercontact, which
can be used forpump control, orsimply to
initiatean alarmcondition. The single control
relay willoperate when the flowmeasured is
outside thehigh orlowtripsettings and can
be configured tooperate with orwithout
“latch”.
LatchSelection :JP2 Position 1– ON (latch/reset)
•Relay energised in normalconditions
i.e. between high and lowlimits giving
a failsafe mode.
•In alarmconditionthe relay will
deenergise and latch in the
deenergised position.
•Close reset contact (7 &8)to reset
relay to energised position. Resetting
willalso reset timerT2.
•If alarmcondition remains afterT2
timertimes out the relay willagain
deenergise and latch.
•If used forpump protect eitherpower
the DFS2 fromthe pump circuit or
close reset contact allowing normal
flowconditions to be established
beforeT2 timertimes out.
Position 2– OFF(Nolatch/reset)
•Relay isdeenergised innormal
conditions i.e. between high and low
limits.
•In alarmconditionsthe relay will
energise.

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
3
Adjustments
Range Selection:(referJP1)
Range1(0–2m/s):-Jumperinposition“1”
Range2(0–6m/s):-Jumperinposition“2”
SettingLowFlowTripPoint:
Moveslide switch“S1”to“Lo”position.Adjustthe lowtrippotentiometeruntil the
bargraphdisplaysthe requiredalarm setting asapercentageof theflowrange
selected.
Example: Range1(0–2m/s)
Bargraphdisplay–50%
Trippoint setting –1,0m/s
SettingHighFlowTripPoint
Moveslide switch“S1”to“Hi” positionandadjust hightrippotentiometertodisplay
therequiredalarm setting.
NB Returnslideswitchtocentreposition fornormaloperation.
Delay-Off TimerT1:
Undernormaloperatingconditionsthe flowmayfluctuatebeyondthe highorlowtrip
settingsmomentarily.Theadjustable0–60sec.timerisadjusted with
potentiometer“T1”.Turnclockwisetoincreasethedelaybeforethe relayoperates.
Delay-OnTimerT2:
Ifthe flowswitchisusedforpumpcontrolitisnecessarytoover-ridethe tripsettings
duringstart-up,until theflowisestablished.
The adjustable0–60sec.timerisadjusted withpotentiometer“T2”. Turnclockwise
toincreasethedelaybeforetherelayoperates.

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
4
MountingThe Transducer
a)Select alocationformountingthesensorat apoint wheretheflowprofileisfully
developed. Generallytheprincipleof 10pipediametersofstraightpipeupstream,
and5pipediametersdownstreamwill suffice,butshouldvalvesorbendsexist
upstreamofthesensor, the amount of straight pipeimmediatelyupstreamwill need
tobe increased.
b)Ensurethat the sensorismounted asfaras
possiblefrompotentialnoisesources,suchas
pumps, controlvalvesetc.and mount the
sensorat approximately3/9o’clockonthe pipe
(ifhorizontal) toavoiderrorsduetoair pockets
on top,orsediment at thebottomof the pipe.
c)Eitherverticalorhorizontalpipe runsareacceptableforsensormounting.
d)Beforeattachingthetransducerheadtothepipe surface,an areaslightlylargerthan
theflatsurfaceof the transducermustbe cleanedtobaremetal. (A small amountof
pipepitting, evenwithspotsofpaintorrust, will not causeproblems).
e)The transducermustbe mountedaccurately, paralleltothepipe axis, forcorrect
performance,andtransducertopipecontact shouldbealongthecentrelineof the
transducerhead.
f)Bondingtothepipe isachieved withsilicone
couplingcompound. Besuretofill inanyair
gapsthatmayremainatthepipetransducer
interfacewithadditionalcompound.
A pipe clampkit isincludedwiththeflowswitch.
It includessilicone couplingcompound,a
Neoprenerubberpad, andfourpolyamide 12
strapsforpipediametersupto300mm. In
applicationswithexcessivevibrationit is
recommended that theNeoprenerubberpad is
insertedbetweenthepipe andthetransducer.
Coupling compoundmustbeapplied toboth
sidesofthepad.
Mountingthe Switch
The DFS2 electronicsishousedinawaterresistanthousing, whichshouldbe
mountedinalocationwheretheambient temperatureiswithintherangestated in
thespecificationsi.e. -10°Cto50°C.
3 O’CLOCKPOSITIONON PIPE
IFHORIZONTAL
GOOD

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
5
TroubleShooting
RelayOperatesWithNo Flow
Possible Cause-Trippoints settoo low
-Vibration on pipe
Corrective Action -Adjust trip points above 0 m/s
-Relocate transducer
-Use Neoprene rubberpadin transducer
mounting
RelayDoes Not Operate
Possible Cause-High trippoint setbelowlowtrip point
-Unit faulty
Corrective Action -Adjust high trip pointabove lowtrip point
-Returnunit to factory
SignalStrengthLEDNot Illuminated,orFlickeringslowly
Possible Cause-No flow
-Insufficientsuspended solids influid
-Bad couplingof transducer
-Incorrect transducerconnections
Corrective Action -Confirmflow
-Inject airinto pipeline
-Check transducermounting
-Check transducerconnections

Instruction Manual 2009
Rev3
DFS2Doppler FlowSwitch
6
Specifications
Measuring Range:0.3 to 2.0 m/s (1)
0.3 to 6.0 m/s (2)
Set Points:0 to 100%of Range
TimerDelays:0 to 60 seconds
Output :1 Relay-1Amp SPDT
TransducerCable:3 metre length
Temperature:Sensor-20to 90°C
Electronics -10 to 50°C
Electronics :IP65 Polycarbonate
Enclosure 120 x120 x55mm
PowerInput :115/230Vac, 50Hz
24Vdc +/-10%
Transducer:IP68 St/Steel
81 x23 x21mm
Indication LED’s:10 LED bargraph
Range selection
HiandLo Alarm
SignalStrength
Failsafe Mode:Selectable
Pipe sizes:25mm to 3000mm
Weight:0.85kg