Ashcroft KM15 Manuals

KM15 PRESSURE TRANSDUCER INSTRUCTION SHEET Output Type Excitation Supply Current 0.5/4.5 V Ratiometric 5V±.5 Vdc 10mA typ 1/5V 8-32 Vdc 10mA typ © 2011 Ashcroft Inc., 250 E. Main St., Stratford, CT 06614-5145, Tel: 203-378-8281, Fax: 203-385-0408, www.ashcroft.com All sales subject to standard terms and conditions of sale. I&M011-10168. Rev. A 5/11 Teflon is a registered trademark of E. I. DuPont RoHS Compliant WARNING! READ BEFORE INSTALLATION 1. GENERAL: A failure resulting in injury or dam- age may be caused by excessive overpressure, excessive vibration or pressure pulsation, excessive instru- ment 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 trans- ducer may cause irreversible electri- cal 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 snub- ber should be installed to eliminate the damaging hammer effects. Fluid ham- mer occurs when a liquid flow is sud- denly 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 out- put 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 termi- nation upward) to prevent possible overpressure damage from frozen media. 3. STATIC ELECTRICAL CHARGES: Any electrical device may be suscepti- ble 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 con- nections. • 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 suit- able ground. Mounting The KM15 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 minimum 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 pressure fitting. DO NOT tighten by using a pipe wrench on the housing. Noise For minimum noise susceptibility, avoid running the transducer’s cable in a con- duit that contains high current AC power cables. Where possible avoid running the cable near inductive equipment. Shield Wiring (Cable Termination Only) 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. Vent Tube (Cable Termination Only) The cable will have a clear Teflon® vent tube that's required at pressure below 500 psi to provide atmospheric refer- ence. The open end should be placed in a dry area.