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Figure 1.83
A typical PTC Thermistor characteristic shown on the following page.
Figure 1.84
Figure 89 PTC Thermistor Temperature-Resistance Value Characteristics
Using the changing voltage drop across the thermistor the voltage into the A2 analog input will vary according to the motor's winding
temperature. If the measured voltage into A2 exceeds 1.17 Vdc the iQpump drive will flash an OH3 alarm on the digital operator and will
either ramp to a stop in the time specified by C1-02 (L1-03 = "0: Ramp to Stop"), coast to a stop (L1-03 = "1: Coast to Stop"), ramp to a
stop at the special fast stopping time specified by C1-09 (L1-03 = "2: Fast-Stop"), or continue operating using the commands received
before the OH3 alarm (L1-03 = "3: Alarm Only"). The Drive's fault contact, MA-MB, will not close.
If the measured voltage into the A2 analog input exceeds 2.34 Vdc the iQpump drive will fault (OH4) and either ramp to a stop in the
time specified by C1-02 (L1-04 = "0: Ramp to Stop"), coast to a stop (L1-04 = "1: Coast to Stop"), ramp to a stop at the special fast
stopping time specified by C1-09 (L1-04 = "2: Fast-Stop"). The Drive's fault contact, MA-MB, will close.
Parameter L1-05 will apply a time delay filter to the A2 analog input when it is configured as the thermistor input. The greater the time
programmed into L1-05 the less responsive the iQpump drive will be to quick changes to the input voltage but the more stable the input
will be. A noisy input will benefit from a greater L1-05 time.
98
Branch resistance
*1
18 k Ω
PTC Thermistor
The resistance value of 18 k Ω is only valid for
*1
using a 3-phase PTC with the characteristics shown in
the figure below.
on following page.
Resistance (ohms)
1330
550
Tr 5
Tr
+V
(+15 V, 20 mA)
A2
(0-10 Vdc)
AC
Figure 88
Class H
Class F
180
150
Tr: Temperature threshold value
Temperature
Tr
Tr+5
YASKAWA TM.iQp.02 iQpump Drive Programming Manual
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