Mitsubishi Electric FR-A800, Instruction Manual

Page: 478 / 1042

(H) Protective function parameter Parameters
5 - 298
External thermal relay input (OH signal, E.OHT)
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.
Connect the recommended 2 W 1 kΩ resistor between the terminal PC and OH. (Refer to page 2-67.)
●
When the control terminal option (FR-A8TP) is used, valid/invalid setting of the terminal OH can
be changed using Pr. 876 "Thermal protector input".
Fig. 5-126:
Connection of an external thermal relay
I002582E
I002583E
Fig. 5-127: Connecting the SF-V5RU thermal protector
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.
U
V
W
OH
SD
M
Motor
Thermal relay protector
Inverter
G1
G2
OH
SD
PC
SF-V5RU Inverter
2 W 1 k
Ω