YASKAWA A1000 Series Technical Manual page 247

Figure 5.87
Motor Protection Using a Positive Temperature Coefficient (PTC)
■
A motor PTC can be connected to an analog input of the drive. This input is used by the drive for motor overheat
protection.
When the motor overheat alarm level is reached, an oH3 alarm will be triggered and the drive will continue operation as
selected in L1-03. When the overheat fault level is reached, an oH4 fault will be triggered, a fault signal will be output,
and the drive will stop the motor using the stop method determined in L1-04.
Connect the PTC between terminals AC and A3 and set jumper S4 on the terminal board to "PTC" like shown in
Figure 5.88. Set parameter H3-05 to 0 and parameter H3-06 to E.
Figure 5.88
The PTC must have the following characteristics for one motor phase. The drives motor overload detection expects 3 of
these PTCs to be connected in series.
Figure 5.89
YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
Operation time (minutes)
10
7
3
1
0.4
0.1
0 100
Figure 5.87 Motor Protection Operation Time
Multi-function input
DIP Switch S4
YEG
A3 (0-10 V)
PTC
thermistor
AC
Figure 5.88 Connection of a Motor PTC
Tr - 5K (oH3 Alarm Level)
Figure 5.89 Motor PTC Characteristics
common_TMonly
Cold start
Hot start
Motor current (%)
150 200
E2-01 = 100% motor current
Drive
MA
Fault output
MB
MC
PTC
M1
M2
AI
Multi-function
M3
digital outputs
M4
M5
M6
common_TMonly
Tr'
Tr + 5K (oH4 Fault Level)
5.8 L: Protection Functions
5
247