6
-74
Continuing Operation at Constant Speed When Frequency Reference Is
Lost
The frequency reference loss detection function continues operation using 80% speed of the frequency refer-
ence before loss when the frequency reference using an analog input is reduced 90% or more in 400 ms.
When the error signal during frequency reference loss is output externally, set H2-01 to H2-03 (multi-function
contact output terminal M1-M2, P1-PC, and P2-PC function selection) to C (frequency reference lost).
Related Constants
Restarting Operation After Transient Fault (Auto Restart Function)
If an Inverter fault occurs during operation, the Inverter will perform self-diagnosis. If no fault is detected, the
Inverter will automatically restart. This is called the auto restart function.
Set the number of auto restarts in constant L5-01. A fault reset is attempted every 5 ms after a fault occurs and
minimum baseblock time has passed. The number of auto restarts is counted when the Inverter attempts a fault
reset and restarts operation. The protection function will operate if a fault continues to occur after auto restart-
ing the number of times set in L5-01.
The auto restart function can be applied to the following faults. If a fault not listed below occurs, the protec-
tion function will operate and the auto restart function will not.
* When L2-01 is set to 1 or 2 (continue operation during momentary power loss)
Auto Restart External Outputs
To output auto restart signals externally, set H2-01 to H2-03 (multi-function contact output terminals M1-M2,
P1-PC, and P2-PC function selection) to 1E (auto restart).
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
MEMO
BUS
Regis-
ter
V/f
V/f
with
PG
Open
Loop
Vec-
tor
Flux
Vec-
tor
L4-05
Operation
when fre-
quency refer-
ence is
missing
0: Stop (Operation follows the
frequency reference.)
1: Operation at 80% speed
continues. (At 80% of speed
before the frequency
reference was lost)
Frequency reference is lost: Fre-
quency reference dropped over
90% in 400 ms.
0 or 1
0
No
A
A
A
A
49DH
• OC (Overcurrent)
• RH (Braking resistor overheated)
• GF (Ground fault)
• RR (Braking transistor error)
• PUF (Fuse blown)
• OL1 (Motor overload)
• OV (Main circuit overvoltage)
• OL2 (Inverter overload)
• UV1 (Main Circuit Undervoltage, Main Circuit MC Operation Failure)
*
• OH1 (Motor overheat)
• PF (Main circuit voltage fault)
• OL3 (Overtorque)
• LF (Output phase failure)
• OL4 (Overtorque)