External Thermal Relay Input (Oh Signal, E.oht); Ptc Thermistor Input; Example Of Ptc Thermistor Characteristics - Mitsubishi FR-A800 Instruction Manual

(H) Protective function parameter
External thermal relay input (OH signal, E.OHT)
Thermal relay protector
Inverter
U
V
W
OH
SD
External thermal relay input connection diagram
• The external thermal relay input (OH) signal is used when using an external thermal relay or a thermal protector built into
the motor to protect the motor from overheating.
• When the thermal relay function is activated, the external thermal operation (E.OHT) shuts off the inverter output.
• For the terminal used for the OH signal input, set "7" in any of Pr.178 to Pr.189 (input terminal function selection) to
assign the function.
• Vector-control-dedicated motors (SF-V5RU) are equipped with thermal protectors.
Inverter
PC
2W1kΩ
OH
SD
Connecting the SF-V5RU thermal protector

Connect the recommended 2W1k
NOTE
• Changing the terminal assignment using Pr.178 to Pr.189 (input terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
PTC thermistor input (Pr.561, Pr.1016, E.PTC)
Inverter
Motor
U
V
W
10
2

PTC thermistor input

connection diagram
• Output from the PTC thermistor, which is built into the motor, can be input to the terminals 2 and 10. If the input from the
PTC thermistor reaches the resistor value set in Pr.561 PTC thermistor protection level, the PTC thermistor operation
(E.PTC) shuts off the inverter output.
• Confirm the characteristic of the PTC thermistor to be used, and set the resistance for Pr.561 around the center of the R1
and R2 values shown on the figure above so that it does not deviate from the protective function activating temperature TN.
If the Pr.561 setting becomes too close to R1 or R2, the protective function activating temperature may be too hot
(protection is delayed), or too cold (too much protection).
• When the PTC thermistor protection is enabled (Pr.561 ≠ "9999"), the resistance value for the PTC thermistor can be
displayed on the operation panel or via RS-485 communication. (Refer to
336
PARAMETERS
Motor
M
SF-V5RU
∗1
G1
G2
Ω
resistor between the terminal PC and OH. (Refer to
Thermistor resistance
R2
Pr.561
R1
Temperature - resistance
existing range

Example of PTC thermistor characteristics

page
Thermistor curve
Thermistor temperature
TN-DT TN+DT
TN
TN: Rated operating temperature
page 359.)
65)