Clothes Washer, Wet Test, Temperature Measurement
(3.e) Inlet Water Temperature Measurements
A signal from each thermocouple attached to the inlet pipe (as shown on Figure
3.e-1 on page 26) to measure the inlet water temperature was collected simultaneously
with the other measurements (from the laser optical tachometer, load cell or force
transducer, and tri-axial accelerometer). The data acquisition device began collecting data
before the clothes washer began operating. The total acquisition time was 3,120 seconds,
using 64 Hz sample rate measurements. The clothes washer contained two lbs (dry
weight) of test clothes, with high water level and a warm water temperature setting.
Note that each measurement started at different time frame thus there were some
minimal delays as shown in Figure 3.e-2 on page 26. The differences (also shown on
Figure 3.e-2 on page 26) were very minimal and thus insufficient to impose any
immediate problem toward the measurement. Since the inlet water was supplied by the
campus-wide water supply, controlling the temperature of the inlet water was redundant
and unnecessary. This is especially true for cold water supply. For the hot water supply
since it is maintained at a constant temperature within an individual building. And the hot
water’s temperature cools off over time whenever the water is not flowing in the water
supply pipe. It gradually rises to approximately the maintained temperature whenever it is
permitted to flow. Thus, variations in the hot inlet water temperature level at different
time frames throughout the laundry cycle will be observed.
Created by Phie Theng Lee
Michigan Technological University
25
Clothes Washer, Wet Test, Temperature Measurement
Thermocouple
Figure 3.e-1, Thermocouple attached to the inlet water pipe.
Regular wash cycle @ 64 Hz sample rate
120
Fast spin speed
Medium spin speed
Slow spin speed
Temperature, degree Fahrenheit
115
110
105
100
95
90
85
0
500
1000
1500
Time, second
2000
2500
3000
Figure 3.e-2, Hot inlet water temperature measurement for Regular Wash Cycle.
Created by Phie Theng Lee
Michigan Technological University
26
Clothes Washer, Wet Test, Temperature Measurement
(3.f) Drain Motor Temperature Measurement
A signal from a thermocouple attached to the housing of the drain motor (as
shown in Figure 3.f-1 on page 28) was collected simultaneously with the other
measurements (i.e. laser tachometer, load cell and tri-axial accelerometer). The data
acquisition device began collecting data before the clothes washer began operating. The
total acquisition time was 3,120 seconds, using 64 Hz sample rate for the measurement.
The clothes washer contained two lbs (dry weight) of test clothes, with high water level
and a warm water temperature setting.
Each measurement started at a different time frame that leads to apparently an
insignificant amount of delay (as shown in Figure 3.f-2 on page 28). Also shown in
Figure 3.f-2 on page 28, the first couple of peaks were at approximately 500 seconds or
eight minutes into the wash cycle, inconsistent maximum temperature levels were due to
the initial temperature of the drain motor. If the measurement was performed at the very
beginning before a series of measurements compared to any other measurement in that
series, the drain motor’s temperature will be lower (the cold start). This behavior will not
persist once the drain motor got past the warm up period, as seen from Figure 3.f-2 on
page 28, the drain motor reached a more consistent maximum temperature level after
approximately 1,250 seconds or twenty minutes into the wash cycle. As the drain motor,
its operating temperatures were within the range of 143° F to 150° F that occurs at the
very end of the drain cycle that spread throughout the entire wash cycle.
Created by Phie Theng Lee
Michigan Technological University
27
Clothes Washer, Wet Test, Temperature Measurement
Thermocouple Located at here
Figure 3.f-1, Thermocouple was attached to the drain motor housing.
Regular wash cycle @ 64 Hz sample rate
Fast spin speed
Medium spin speed
Slow spin speed
Temperature, degree Fahrenheit
160
150
140
130
120
110
100
0
500
1000
1500
2000
Time, second
2500
3000
3500
Figure 3.f-2, Drain motor temperature measurement for Regular wash cycle.
Created by Phie Theng Lee
Michigan Technological University
28
Clothes Washer, Wet Test, Temperature Measurement
(3.g) Drive/Spin Motor Temperature Measurement
Two different types of thermocouples were used to measure the clothes washer’s
drive motor’s core temperature level. The thermocouples were attached at two different
locations of the drive/spin motor’s coil. The measurement was conducted simultaneously
with the other measurements (from laser tachometer, load cell and tri-axial
accelerometer). The data acquisition device began collecting data before the clothes
washer began operating. The total acquisition time was 3,120 seconds (entire wash
cycle), using 64 Hz measurement sample rate. The clothes washer contained two lbs (dry
weight) of test clothes, with high water level and a warm water temperature setting.
As shown in Figure 3.g-1 on page 30, both of the thermocouples were attached to
two different copper coils that were located at different spots of the stator. The main
reason for placing two different types of thermocouples at two different spots of the stator
is to distinguish any observable differences in temperature level by using two different
thermocouples with different thicknesses. If both of the thermocouples were properly
calibrated, and if both of the thermocouples were measuring the temperature level of the
same object, then the temperature level obtained should be approximately the same, as
shown in Figure 3.g-2 on page 30 and Figure 3.g-3 on page 31. The temperature level as
measured during the clothes washer was cycle at Fast spin speed was relatively higher
then the rest of the cycles as shown in Figure 3.g-2 on page 30 and Figure 3.g-3 on page
31. This was due to the drive motor requiring higher amount of energy in order to spin up
to the higher spin speed. It was approximately the same for the Medium and Slow spin
speed. The stator is the internal component of the clothes washer’s drive motor, the stator
is fixed and does not rotate. The stator is the white plastic piece as shown in the middle of
Figure 3.g-1 on page 30.
Created by Phie Theng Lee
Michigan Technological University
29
Clothes Washer, Wet Test, Temperature Measurement
Thermocouples
Figure 3.g-1, Thermocouples attached to the clothes washer’s copper coil.
Regular wash cycle @ 64 Hz sample rate, Thermocouple # 1
Fast spin speed
Medium spin speed
Slow spin speed
Temperature, degree Fahrenheit
180
160
140
120
100
80
0
500
1000
1500
2000
Time, second
2500
3000
3500
Figure 3.g-2, Drive/spin motor temperature measurement for Regular wash cycle with thermocouple
# 1.
Created by Phie Theng Lee
Michigan Technological University
30
Clothes Washer, Wet Test, Temperature Measurement
Regular wash cycle @ 64 Hz sample rate, Thermocouple # 2
Fast spin speed
Medium spin speed
Slow spin speed
Temperature, degree Fahrenheit
180
160
140
120
100
80
0
500
1000
1500
2000
Time, second
2500
3000
3500
Figure 3.g-3, Drive/spin motor temperature measurement for Regular wash cycle with thermocouple
# 2.
Created by Phie Theng Lee
Michigan Technological University
31