Endress+Hauser RMS 621 - Page 53

RMS 621 9 Fault-finding
Endress+Hauser 53
Steam condensate temperature The measured or calculated
temperature equals the
condensate temperature of
saturated steam
• Check application,
transmitters and connected
sensors.
• Take steps to improve
process control - increase
temperature, decrease
pressure.
• Possible inaccurate temperature
or pressure measurement; purely
a calculation of the phase change
from steam to water, that really
does not occur; inaccuracy from
set up of a temperature
compensation (approx. 1 - 3 °C)
offset.
Water: Distillation temperature The measured temperature is equal
to the distillation
temperature of water (water
evaporates!)
• Check application,
transmitters and connected
sensors.
• Take steps to improve
process control - decrease
temperature, increase
pressure.
Signal range violation: "Channel
ident." "Signal ident."
Output current signal is smaller
than 3.8 mA or higher than 20.5
mA.
• Check if the current output is
correctly scaled.
• Change the scale start and end
values.
Cable open circuit: "Channel ident."
"Signal ident.")
Input current is smaller than 3.6
mA or higher than 21 mA.
• Incorrect cabling
• Sensor not set to 4–20 mA range.
• Functional fault at sensor
• Incorrect end value set-up on
flowmeter.
• Check sensor set-up
• Check sensor function
• Check end value of connected
flowmeter
• Check cabling
Cable open circuit: "Channel ident."
"Signal ident.")
Too high resistance at the PT 100
input, e.g. caused by short circuit or
cable breakage
• Incorrect cabling
• PT100 sensor defective
• Check cabling
• Check PT100 sensor function
Min. temp. diff. undercut Overhang of the preset
temperature differential
Check actual temperature
values and the preset minimum
temperature differential.
Alarm set point violation
• "Alarm set point ident." <
"Threshold" "Eng. unit"
• "Alarm set point ident." >
"Threshold" "Eng. unit"
• "Alarm set point ident." >
"Gradient" "Eng. unit"
• "Alarm set point ident. <
"Gradient" "Eng. unit"
• "User defined message"
Alarm set point violation (higher or
lower than).
(→ Setup, Alarm set points, Chap.
6.4.3)
• Acknowledge alarm message if
the function “Alarm set
point/Event text/Display and
acknowledge“ has been set up.
(→ Setup, Alarm set points,
Chap. 6.4.3)
• If required check application
• If required reset alarm set points
Display message Cause Cure