Interview questions on Bearing temperature measurement
https://instrumentationtools.blogspot.com/2015/05/Questions-on-bearing-temperature-measurement.html
1.what approximately is the bearing high temperature
alarm and shutdown setting?
High speed bearings are protected against high temperatures.
The high temperature alarm and shutdown instrument are generally set at 95degee
C and 105degee C (refer to the station drawings for the exact
settings/parameters).
2.What types of primary elements are used
to measure the compressor bearing temperature? Give example with the equipment
name.
At lower range of temperature ‘RTD’ (resistance
temperature detector)is preferred to thermocouples.
On dresser gas compressors: PT 100-RTD is used for measuring the journal and thrust
bearing temperature.
On solar gas compressors: ‘k’ type thermocouple is used for measuring the journal
and thrust bearing temperature.
3.What maybe the reasons, if a compressor
bearing temperature increases?
The following are the possible for compressor bearing
temperature rise:
Defective bearing
Low lube oil supply pressure
Aged lube oil
Excessive compressor load
Dirty lube oil cooler
Lube oil cooler fan running at low speed
Defective thermostatic valve in the lube oil to cooler line
Defective bearing
Low lube oil supply pressure
Aged lube oil
Excessive compressor load
Dirty lube oil cooler
Lube oil cooler fan running at low speed
Defective thermostatic valve in the lube oil to cooler line
4.which of the two-‘resistance and
thermo-couple’- is recommended for measuring a bearing temperature?
Resistance Temperature Detector- RTD is preferred to
thermo-couple for measuring the bearing temperature. RTD is more accurate and
linear in measuring temperature between the range -200degee C to +200degee C.
5.What are the bearing temperature
instrument manufactures names?
PDO is using the following manufacture instruments for
measuring the bearing temperature:
DYMAC, RIS-Rochester instruments Ltd.…etc.
6.Which of the above manufacturer’s
product is more reliable and why?
RIS-Rochester Instrument Ltd. Performance is better than
DYMAC.
RIS has less drifting in temperature measurement.
On line zero and span can be read
Individual card output can be recorded
Choice can be made in the input for a RTD or a Thermocouple
RIS has less drifting in temperature measurement.
On line zero and span can be read
Individual card output can be recorded
Choice can be made in the input for a RTD or a Thermocouple
