Omega SF User guide

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Series SF Sight Flow Transmitter

1/2˝ FEMALE NPT

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Specications - Installation and Operating Instructions

Bulletin F-41-SF

Series SF Sight Flow Transmitter integrates tangential turbine technology with

hermetically sealed circuitry to provide accurate ow measurement and control in the

harshest environments. The 2-wire loop-powered design transmits a 4-20 mA signal

proportional to ow rate. Models can accurately measure ow in both directions and can be mounted in any orientation. Series SF Transmitters are ideal for measuring ow

rates in cooling and lubrication circuits, HVAC systems, aggressive chemical metering, and batching systems.

MECHANICAL INSTALLATION

The Series SF Sight Flow Transmitter has a 1/2˝ female NPT plumbing connections. It is recommended to use a paste type pipe sealant on the threads. Teon tape sealant can also be used as long as it is applied so the tape does not enter the ow stream

(pieces of tape can wrap around the turbine and impeded rotation).

The recommended mounting orientation would be any plane that will place the axis of the turbine vertical or horizontal with respect to ground. The unit will operate satisfactory with the axis at other angles, but side loading of the bearing surfaces will lead to premature wear of the rotating parts.

For the best ow measurement results, place the inlet (references to “inlet” and “outlet” refer to unidirectional systems) of the ow sensor at least 10 straight pipe diameters downstream from any tting, valve, elbow, reducer, etc. that causes nonstable ow conditions. Ideally, 5 straight pipe diameters should be placed at the outlet of the sensor. If the sensor must be placed closer to a source of nonstable ow than the

recommended distances, some instability of the output signal may result. The average signal will be accurate.

Place the sensor in such a position that the round access cover can be removed for

cleaning and turbine servicing. A union placed near the sensor is recommended to allow easy removal.

ELECTRICAL INSTALLATION

The Series SF Sight Flow Transmitter is a 2-wire loop-powered device desined to

transmit a 4-20 mA signal proportional to ow rate. The noise-immune current

transmission from the sensor can be routed with low cost two conductor twisted-pair

cable. The current operates on 12-35 VDC and requires a source capable of supplying

at least 20 mA of current. The circuit has built-in polarity protection and over-current limiting to protect both the sensor and what the sensor is connected to.

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SPECIFICATIONS

Service: Compatible liquids.

Wetted Materials: 316 SS shaft and case, Iglide

-EPR units and acetal copolymer, (polycarbonate cover on Model SF11).

Flow Range: 0.5 to 15 GPM (2 to 60 LPM). Accuracy: ±2% FS. Repeatability: 0.5% FS. Temperature Limits: 20 to 225°F (-7 to 107°C). Pressure Limits: 500 psig (34 bar) Model SF10; 200 psig (14 bar) Model SF11. Response Time: 2 s to 90% (step change in ow rate). Supply Voltage: 12-35 VDC. Output: 4-20 mA. Loop Resistance: 1150 Ω max.

Process Connection: 1/2˝ female NPT. Electrical Connection: Wire leads: 22 AWG x 9´ (2.7 m). Max. Particle Size: 100 µm.

Agency Approvals: CE.

MODEL CHART Model Cover Material SF10

316 SS

SF11

Clear polycarbonate

To connect the sensor:

1. Connect the red wire from the sensor to the positive 12-35 VDC power supply

output.

2. Connect the black wire from the sensor to the positive side of the loop load (resistor,

chart recorder, data aquisition board, meter, etc.). This connection may be labeled “4-20mAInput” on some devices.

3. If applicable, connect the negative side of the loop load to the negative side of the

power supply.

4. Apply power to the system.

5. If everything ois operating correctly, the green LED on the sensor will dimly illuminate and 4 mA will be owing in the loop. If uid is owing through the sensor,

the current will be higher than 4 mA.

Troubleshooting

If the LED does not illuminate:

• Check wiring terminations for good connections.

• Check wiring polarity.

• Verify correct supply voltage.

• Insure the load impedance is within allowable limits.

• Apply the DC supply voltage directly across the sensor wires. If the LED does illuminate, the load is either: too great of impedance or an open circuit. If the LED

does not illuminate, the sensor’s lead wires or circuit are defective.

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bearings, Buna-N seal or EPR for

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Phone: 219-879-8000

Fax: 219-872-9057

www.dwyer-inst.com

e-mail: [email protected]

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MAINTENANCE

The Series SF Flow Transmitter is designed to provide years of low maintenance service in industrial environments. As with all mechanical rotating devices, the bearing surfaces will wear with use. The life of the parts will depend on factors such

as cleanliness of uid, media, mounting orientation, temperature, uid velocity and frequency of operation. The sensor was designed with simple eld replacement of the

rotating parts.

To inspect or replace the rotating components:

1. Relieve pressure in the piping system.

2. Remove the retainer ring that secures the turbine access cover.

3. Remove the access cover with pliers, taking care not to damage the o-ring seal.

4. Pull out turbine assembly and shaft.

5. Inspect the shaft for things that may have wrapped around it.

6. Inspect the turbine bearing surface for wear and elongation. Replace as necessary.

7. Clean any rust off of the magnets that may have accumulated.

8. Reassemble the unit by placing the turbine into the body cavity with the two magnet pockets facing inward. Place the shaft into the turbine hole and guide it into the retaining hole in the body cavity. Lubricate the o-ring with glycerine or other lubricant and press it into the pocket of the body. Replace the retaining ring

securely before applying pressure to the system.

Circuit Recalibration:

1. Place a milliamp meter into the current loop.

2. Turn off the ow going through the sensor. Adjust the OFFSET control for a reading

of 4 mA on the milliamp meter.

3. Adjust the ow rate through the sensor to full ow rate. Adjust the SPAN control for a reading of 20 mA on the milliamp meter. The zero and span adjustment are not interactive and should require additional adjustments.