Installation Of A Thermal Relay (Thr) - Toshiba TOSVERT VF-AS3 Instruction Manual

Sink logic
MCCB or
ELCB
• Be sure to have interlock for the commercial power supply is applied to the inverter output ter-
minal.
• Do not turn the magnetic contactor (MC) in the secondary circuit ON/OFF during run. It can
cause failure due to rush current flowing to the inverter.
Important
• Install a surge absorber on the exciting coil of a magnetic contactor (MC).
10. 2. 4

Installation of a thermal relay (THR)

Use an electronic thermal protector of the inverter for motor overload protection. Set a motor overload pro-
tection level with a parameter according to the motor rating.
However, in the following cases, install a thermal relay (THR) between the inverter and motor (secondary
side).
• Running multiple motors simultaneously with one inverter.
In this case, install a thermal relay on each motor.
• Running a motor with smaller output than applicable motor output of the standard specification
(When the motor capacity is too small to set with a parameter of the motor overload protection level).
For details on motor overload protection level, refer to [5. 2. 5].
To give sufficient protection for the motor running in a low-speed range, the use of a motor with motor
winding embedded type thermal relay is recommended.
MC1
Inverter
MC2
U/T1
R/L1
S/L2 V/T2
T/L3 W/T3
R1A
R1B
R1C
R2A
R2B
R2C
10-9
For motor protection
THR
MC3
10. Selection and installation of peripheral devices
E6582062
Motor
M
3
9
10