Ashcroft KX Operating Manual

Download

Page 1

1000

750

500

250

1182

Load Limitations 4-20mA Output Only

LOOP

)

MODEL KX THIN FILM PRESSURE TRANSDUCER INSTRUCTION SHEET

WARNING! READ

m m

BEFORE INSTALLATION

1. GENERAL:

A failure resulting in injury or damage may be caused by excessive overpressure, excessive vibration or pressure pulsation, excessive instrument temperature, corrosion of the pressure containing parts, or other misuse. Consult Ashcroft Inc., Stratford, Connecticut, USA before installing if there are any questions or concerns.

2. OVERPRESSURE:

Pressure spikes in excess of the rated overpressure capability of the transducer may cause irreversible electrical and/ or mechanical damage to the pressure measuring and containing elements.

Fluid hammer and surges can destroy any pressure transducer and must always be avoided. A pressure snubber should be installed to eliminate the damaging hammer effects. Fluid hammer occurs when a liquid ﬂow is suddenly stopped, as with quick closing solenoid valves. Surges occur when ﬂow is suddenly begun, as when a pump is turned on at full power or a valve is quickly opened.

Liquid surges are particularly damaging to pressure transducers if the pipe is originally empty. To avoid damaging surges, ﬂuid lines should remain full (if possible), pumps should be brought up to power slowly, and valves opened slowly. To avoid damage from both ﬂuid hammer and surges, a surge chamber should be installed.

Symptoms of ﬂuid hammer and surge's

damaging effects:

• Pressure transducer exhibits an output

at zero pressure (large zero offset).

• Pressure transducer output remains

constant regardless of pressure

• In severe cases, there will be no output.

FREEZING:

Prohibit freezing of media in pressure port. Unit should be drained (mount in vertical position with electrical termination upward) to prevent possible overpressure damage from frozen media.

3. STATIC ELECTRICAL CHARGES:

Any electrical device may be susceptible to damage when exposed to static electrical charges. To avoid damage to the

transducer observe the following:

• Ground the body of the transducer

BEFORE making any electrical connections.

• When disconnecting, remove the

ground LAST!

Note: The shield and drain wire in the cable (if supplied) is not connected to the transducer body, and is not a suitable ground.

Mounting Although the unit can withstand normal vibration without damage or signiﬁcant output effects, it is always good practice to mount the transducer where there is minimum vibration.

Power Supply The supply voltage for the 1-5 and 1-6 Vdc output transducers must be within the range of 10 to 36 Vdc. The maximum supply voltage for a 4-20mA current output transducer is 36 Vdc while the minimum supply voltage is dependent upon the loop resistance of the circuit. The ﬁgure below shows the minimum supply voltage (V required for a given loop resistance (R

min

LOOP

)

OPERATING REGION

= 10V+ (.022A x RL)

min

= RS + R

= Loop Resistance (ohms)

= Sense Resistance (ohms)

= Wire Resistance (ohms)

Noise

For minimum noise susceptibility, avoid running the transducer's cable in a conduit that contains high current ac power cables. Where possible avoid running the cable near inductive equipment.

Shield Wiring Connect the braided shield to the guard terminal on the reading instrument (meter, etc.) if available or to ground or to the power supply negative terminal.

Adjustment Potentiometers The zero and span pots are accessible through the top of the case. Loosen the collar and separate the top carefully. The zero pot is marked with a white dot.

Vent Tube The cable will have a clear Teﬂon vent tube that's required at pressure below 500 psi to provide atmospheric reference. The open end should be placed in a dry area.

© 2011 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614, USA • Tel: 203-378-8281, Fax: 203-385-0402 • email: info@ashcrfoft.com, www.ashcroft.com. All speciﬁcations subject to change without notice. All sales subject to standard terms and conditions of sale. I&M011-10156 (250-A152) Rev. A 5/11

Page 2

MODEL KX THIN FILM

6.1

5.2

1/2 NPT CONDUIT FITTING

O-RING SEAL

5/16 18 UNC THREAD

1.032

4.9

4.2

1/2 NPT (C1)

1.06

4.9

4.2

1/2 NPT (C1)

1.06

–

POWER SUPPLY

(+)

(–)

METER

TRANSDUCER

–

V+

V–

PIN 1

PIN 2

4-20 mA

–

POWER SUPPLY

METER

TRANSDUCER

(Common)

(+ Power)

(+ Output)

PIN 1

PIN 2

PIN 3

3-Wire Voltage

PRESSURE TRANSDUCER INSTRUCTION SHEET

KX Series – Electrical Connections

Voltage Output Units 1-5, 1-6 Vdc

Cable Type C1

Red = + Power Black = Common White = Output

DIN Type

PIN-1 = + Power

PIN-2 = Common PIN-3 = Output

Current Output Units 4-20mA

Cable Type C1

Red = + Power Black = – Power

DIN Type

PIN-1 = + Power PIN-2 = – Power

KX Series – Wiring Diagrams

KX Series – Recalibration Instructions

1. Apply 0% Full Scale Pressure.

2. Set the output using the Zero adjustment potentiometer.

3. Apply 100% Full Scale Pressure.

4. Set the output using the Span adjustment potentiometer.

5. Repeat steps 1 thru 4 as necessary.

KX Series Dimensions