ASHCROFT K1, K2, K8 Pressure Transducer Instruction Manual
- June 3, 2024
- ASHCROFT
Table of Contents
ASHCROFT K1, K2, K8 Pressure Transducer
WARNING! READ BEFORE INSTALLATION
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., Strat- ford, Connecticut, USA before installing if
there are any questions or concerns.
OVERPRESSURE
Pressure spikes in excess of the rated overpressure capability of the
transducer may cause irreversible electrical and/or mechanical damage to the
pressure mea suring 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 ham-
mer 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 damag- ing 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.
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:
Operator/installer should follow proper ESD (electrostatic discharge)
protection procedures before handling the pressure transducer
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
The transducer requires no special mounting hardware, and can be mounted in
any plane with negligible position error.
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 mini- mum vibration.
For units with NPT type pressure fittings apply teflon tape or an equivalent
sealant to the threads before installing.
When tightening, apply a wrench to the hex wrench flats located just above the
pres Sure fitting. DO NOT tighten by using a pipe wrench on the housing.
POWER SUPPLY – K1 Models Only
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 volt age 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 load limitation chart shows the minimum supply voltage (Vmin) required for a given loop resistance (RLooP).
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
four screws 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.
OUTPUT- K8 Only
Sensitivity may be from 6 mV/V to 18 mVW for any individual transducer. Zero
offset is within 3 mV/V. Output is proportional to supply voltage
(ratiometric).
EXCITATION-K8 & K2
For proper operation a voltage within the range of 5 to 10 Vdc must be applied
be- tween the transducer’s supply terminals.
Wiring Diagrams for All Transducers
4-Wire Ratiometric (mVV)
3-Wire Voltage
Dimensions
NOTE: All dimensions are decimal inches
K1 Transducers Electrical Connections
Voltage Output Units 1-5, 1-6 Vdc
Current Output Units 4-20mA
K2 Transducers – Electrical Connections
Ratiometric (mVN)
K8 Transducers Electrical Connections
Ratiometric (mV/V)
Special Wiring – See “X”Variation On Unit Label
Recalibration Instructions:
- Apply 0% Full Scale Pressure.
- Apply 100% Full Scale Pressure.
- Set the output using the Zero adjustment potentiometer.
- Set the output using the Span adjustment potentiometer.
- Repeat steps 1 thru 4 as necessary.
2012 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614, USA.
Tel: 203-378-8281
Fax: 203-378-0499, All specifications
are subject to change without notice.
All sales subject to standard terms and conditions. All rights reserved.
www.ashcroft.com.
1&MO11-10063-1/01 (250-2924). Rev. A 7/12