Fuji Electric FRENIC-HVAC User Manual page 433

E65 Reference Loss Detection (Continuous running frequency)
When the analog frequency command (setting through terminal [12], [C1], or [V2]) has
dropped below 10% of the reference frequency within 400 ms, the inverter presumes that the
analog frequency command wire has been broken and continues its operation at the frequency
determined by the ratio specified by E65 to the reference frequency.  Refer to E20 through
E24 and E27 (data = 33).
When the frequency command level (in voltage or current) returns to a level higher than that
specified by E65, the inverter presumes that the broken wire has been fixed and continues to
run following the frequency command.
In the diagram above, f1 is the level of the analog frequency command sampled at any given
time. The sampling is repeated at regular intervals to continually monitor the wiring
connection of the analog frequency command.
- Data setting range: Decel (Decelerate to stop)
Avoid an abrupt voltage or current change for the analog frequency command. An
abrupt change may be interpreted as a wire break.
When E65 = OFF (Cancel), the inverter issues the REF OFF signal ("Reference
loss detected") but does not change the reference frequency so that it runs at the
analog frequency command as specified.
When E65 = "Decel" or OFF, the reference frequency level at which the broken
wire is recognized as fixed is "f1 × 0.2."
When E65 = "100" (%) or higher, the reference frequency level at which the wire is
recognized as fixed is "f1 × 1."
The reference loss detection is not affected by the setting of analog input adjustment
(filter time constants: C33, C38, and C43).
20 to 120 %
OFF (Cancel)
6-123
6.3 Details of Function Codes