Motor overload protection operates in the area between a cold start and a hot start.
• Cold start: Characteristics of motor protection operation time in response to an overload situation that was suddenly reached
when starting a stationary motor.
• Hot start: Characteristics of motor protection operation time in response to an overload situation that occurred while the
motor was operating continuously at or below its rated current.
Operation time (minutes)
Cold start
(characteristics when an
overload occurs at a
complete stop)
Hot start
(characteristics when an
overload occurs during
continuous operation at 100%)
Motor current (%)
E2-01 = 100% motor current
10
7
3
1
0.4
0.1
0
100
150
200
Figure i.54 Protection Operation Time for General Purpose Motors at the Rated Output Frequency
n
Motor Protection Using a Positive Temperature Coefficient (PTC) Thermistor
Connect a motor PTC can to an analog input of the drive for motor overheat protection.
The motor overheat alarm level triggers an oH3 alarm and the drive continues the operation selected in L1-03. The overheat
fault level triggers an oH4 fault, outputs a fault signal, and the drive stops the motor using the stop method selected in L1-04.
Connect the PTC between terminals AC and A3 and install a 12 kOhm resistor between terminals V+ and A3 as shown in
. Set H3-05 to 0 and H3-06 to E.
Note:
A 12 kOhm resistor must be connected between one of the terminals A1, A2, or A3 and V+ for PTC functionality. Connect the 12 kOhm
resistor to the same terminal as the PTC input. Do not connect terminals V+ to AC, or damage to the drive may result.
Drive
Multi-function input
PTC
thermistor
A3 (0-10 V)
AC
V+ Power supply
+10.5 Vdc,
max. 20 mA
12 kOhm
resistor
PTC external circuit
(customer supplied)
Figure i.55 Connection of a Motor PTC
The PTC must exhibit the characteristics shown in
in one motor phase. The motor overload protection of the drive
expects 3 of these PTCs to be connected in a series.
i.5 Start-Up Programming and Operation
60
YASKAWA ELECTRIC TOEP C710636 11E Z1000U HVAC MATRIX Drive Quick Start Guide