Cooper Instruments & Systems PTT 260 Digital Pressure Sensor - Manual (Page 2)

CF 197 ii I&M011-10172 Rev A 5/11
WARNING! READ
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 Cooper Instruments 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.
3. 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.
4. 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.