Mitsubishi Electric FR-A800, Instruction Manual

Page: 476 / 1042

(H) Protective function parameter Parameters
5 - 296
Set two types of electronic thermal O/L relays (Pr. 51)
●
These settings are used when rotating two motors with different rated current separately by a
single inverter. (When rotating two motors together, use an external thermal relay.)
●
Set the rated motor current for the second motor in Pr. 51.
●
When the RT signal is ON, thermal protection is provided based on the Pr. 51 setting.
Fig. 5-123:
Operating two motors by a single inverter
I002581E
Pr. 450
"Second applied
motor"
Pr. 9
"Electronic thermal
O/L relay"
Pr. 51
"Second electronic
thermal O/L relay"
RT-OFF RT-ON
No.1
Motor
No.2
Motor
No.1
motor
No.2
motor
9999 0
9999 × × × ×
0 × × × ×
0.01 to 500 (0.1 to 3600) × Δ ×

9999 Other than 0
9999

×

×
0

× Δ ×
0.01 to 500 (0.1 to 3600)

Δ Δ

Other than 9999 0
9999 × × × ×
0 × × × ×
0.01 to 500 (0.1 to 3600) × Δ ×

Other than 9999 Other than 0
9999

Δ Δ

0

× Δ ×
0.01 to 500 (0.1 to 3600)

Δ Δ


: Values are accumulated by using the output current.
Δ : Values are accumulated by assuming the output current is "0 A" (cooling processing).
× : Electronic thermal O/L relay does not operate.
Tab. 5-117: Switching of the electronic thermal relay
NOTES The RT signal is a second function selection signal. The RT signal also enables other second func-
tions. (Refer to page 5-428.)
The RT signal is assigned to the terminal RT in the initial setting. Set "3" in any of Pr. 178 to Pr. 189
(input terminal function selection), to assign the RT signal to another terminal.
MC
IM
IM
MC
U
V
W
RT
SD