Download P15280 Sensor Guide

P15280 Sensor Guide
Sections
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Types of sensors
Specification/Calibration
Thermocouple Set-up on test bench
Testing functionality of sensors
Troubleshooting/Tips
Types of Sensors
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2: K-type thermometer
o Sense temperature of AC motor and DC battery
1: CR5310-600 DC Voltage Transducer
o Monitor DC voltage of batteries of up to 600Vdc
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1: CR4511-500 AC Voltage Transducer
o Monitor AC voltage of motor of up to 500Vac
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2: Honeywell CSLA2EL Current transducer
o Monitor AC current of motor and DC current of batteries of up to 500A AC/DC
Specification/Calibration
Sensor
Senses
CR5310-600
CR4511-500
CSLA2EL
Analog/Digital
Output
Analog
Analog
Analog
Power Supply
Needed
DC voltage
24V
AC voltage
24V
AC/DC current 10V
K-thermocouple
Analog
Temperature
N/A
Output range
Calibration
0-5Vdc
0-10Vdc
Depends on
supply voltage
Read by
program
Vin=120Vout
Vin=50Vout
Current=(Vout5)/(4.3*10^-3)
Read by
Program
Where
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Vout is the voltage outputted by sensor
Vin is the voltage that is monitored
Please note that Vin for AC voltage is RMS value and is equal to Vpp/(2*radical(2)).
The section below shows the pin layout and specifications for each sensor used in this project.
1. CR4511-500 (AC voltage transducer)
2. CR5310-600 (DC voltage transducer)
3. CSLA2EL (AC/DC current transducer)
Pin schematic is not available. There are three pins, (+) for positive power supply, (-) for ground and (o)
for output.
Thermocouple Set-up on test bench
**Please refer to hardware section of Electrical Operation Manual for detailed information in setting
up voltage and current sensor on the test bench
There are two thermocouples used in this project to monitor temperature of the motor and battery.
Below are pictures of their position for test bench purpose. **Please note that for better accuracy,
thermocouples with a shorter rod should be used. Also, the location of the thermocouple may vary,
depending on the motor used. The motor shown in the picture is an old DC motor, for the AC motor to
be used by Hot Wheelz, please check with manufacturer to see which location is most vital for
temperature monitoring. The same goes for the batteries.
The pictures below show the NI DAQ (left) used for processing the analog output data from the sensors.
The module shown on the right is used to connect the leads of the thermocouple. Please note that the
program is currently set to process thermocouple data in ports 0 and 2 of the module. If additional
thermocouples are used for future purposes, be sure to turn on acquisition from the other ports in the
software code.
Testing functionality of the Sensors
The section below talks about the verification of the sensors before placing onto the test bench. For step
by step procedures of the tests, please refer to P15280 Test Plan documentation. The section below talks
about the results from testing sensors used in this project. Please refer to pin information mentioned in
section above to correctly connect each sensor.
A. AC voltage transducer test
For the AC voltage transducer, 24Vdc is applied as the power supply between pins (5) and (6). AC voltage
is applied to pins (1) and (3). Output result can be read from pins (8) and (6). The table below shows the
output DC voltage from the sensor as the result of the various AC voltages applied. The sensitivity equation
calibration Vin=50Vout is applied to the result to find the actual AC voltage of the system, where Vout is the
voltage output by sensor and calculated Vout is the output we expect from the sensor for the input voltage
applied. For additional clarification, Vpp refers to the value from AC power supply. To convert it to Vin, use
the formula Vin = Vpp/(2*radical(2)). As can be seen, the sensor is more accurate as higher voltages are
applied.
(Please note that this is only application for when an AC motor is used, otherwise, use setup/calibration
from the DC voltage transducer).
DC voltage transducer test
For the DC voltage transducer, the setup is identical to AC voltage transducer. The sensitivity equation is
Vin=120Vout. Like the AC voltage transducer, the readings are more accurate as higher voltages are
applied.
B. Current Sensor test
The photo above contains the setup for testing the current transducers. 8 Vdc is supplied to power the
sensor (Test bench will use Vdd as 10Vdc) through (+) and (-) pin. Different input voltages are applied and
connected to the 10W resistor (to generate different currents) and through the current sensor. The
current received by the sensor is amplified by the amount of loops (N). In this case there are 20 loops. The
output is hooked up to a multimeter through the (o) pin and reads as Vdd/2+4.3mV*N*current. Referring
to the results table below, the error ranged from 0-10%.
Please note that the test uses 20 loops since the sensor senses up to 500A and has trouble measuring low
amperage. Also, a 10W resistor is used since Power = Voltage * Current and normal 0.5W resistors from
EE labs will easily burn up.
C. Thermocouple test
The picture below contains the setup for testing thermocouples. Two thermocouples are hooked up to
the data acquisition modules. The cooking thermometer shown is used to verify the output. Ice is applied
to the bowl of water until the temperature reached ~0 degrees Celsius. The temperature is captured at 5
different points and can be seen in the table above, the error ranges from 0 to 1.4 degrees Celsius between
the two thermocouple outputs and the cooking thermometer.
Troubleshooting/Additional Tips
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Current Transducer Pins are very fragile, as they are exposed and are connecting directly to the
circuit board. Take extra care when connecting/disconnecting connectors around pins and try to
limit possible sources of vibration to the pins during testing.
K-type thermocouples used in this project are connected to a long metal rod which senses
temperature. For more accurate measurements, source a shorter rod so that the sense area is
smaller and more precise.
Voltage transducers used in this project have warranty from manufacturer until September 2016.
This warranty covers the cost of troubleshooting and mailing fee from the manufacturer back to
you.
Make sure voltage transducers have a regulated power supply. For some reason, the power supply
from 3rd floor EE Electronics labs managed to burn the supply fuse a couple of times.