YASKAWA HV600 Technical Reference page 397

Emergency Override PID Mode Operation
Emergency Override will operate in PID mode and maintain the setpoint when S6-02 = 2 [System PID Mode] or S6-
02 = 3 [Independent PID Mode].
• When S6-02 = 2:
Emergency Override uses the system units set in b5-38 [PID User Unit Display Scaling], b5-39 [PID User Unit
Display Digits], and b5-46 [PID Unit Display Selection] and the normally selected PID Feedback and PID Setpoint.
If it is necessary to override the PID Feedback and the PID Setpoint, set an analog input to H3-xx = 2B [Emergency
Override PID Feedback] for the PID Feedback and H3-xx = 2C [Emergency Override PID Setpoint] for the PID
Setpoint.
• When S6-02 =3:
Emergency Override uses the dedicated units set in S6-03 [EMOVR Independent PID Scale], S6-04 [EMOVR
Independent PID Unit], and S6-05 [EMOVR Independent PID Unit Digit]. The PID Setpoint uses the setpoint set in
S6-06 [EMOVR PID Setpoint] if you do not set H3-xx = 2C [Emergency Override PID Setpoint]. The PID
Feedback uses the system Feedback set in H3-xx = B [PID Feedback] if you do not set H3-xx = 2B [Emergency
Override PID Feedback].
When S6-02 = 2 or 3:
• MEMOBUS register 3A95H can override the Emergency Override PID Feedback when you set register 3A93H bit
4 to ON.
• MEMOBUS register 3A96H can override the Emergency Override PID Setpoint when you set register 3A93H bit 5
to ON.
Note:
• The drive will not memorize MEMOBUS registers 3A93H, 3A95H, and 3A96H while you re-energize the drive.
• When S6-02 = 2 or 3, the drive will also run in Standard PID mode when b5-01 = 0 or 3 [PID Mode Setting = Disabled or Fref + PID
Trim]. The drive operation for Fref + PID Trim is not available during Emergency Override operation.
Interactions with Other Drive Functions
If the drive is detecting a fault that you can reset when the Emergency Override command is activated, the drive will
clear the fault. These settings do not have an effect:
• The settings of S6-11 [EMOVR Drive Protection Fault ON] to S6-14 [EMOVR Application 1 Fault ON]
• How many Auto Restart Attempts remain
Note:
The drive cannot reset Err [EEPROM Write Error] or SCF [Safety Circuit Fault] faults.
The Emergency Override function has priority over these functions:
• Fault Restart operation
– L5-01 [Number of Auto-Restart Attempts]
When the Emergency Override is active, the drive resets the internal counter of L5-01 to 0 and the drive will
allow an infinite number of Auto Restart Attempts.
– Fault retry parameters: H5-36 [CE Fault Restart Select], L5-07 [Fault Reset Enable Select Grp1], L5-08 [Fault
Reset Enable Select Grp2], and L5-53 [Thermostat Fault Retry Selection]
When Emergency Override is active, the drive ignores these parameter settings and the drive will always allow an
infinite number of Auto Restart Attempts.
• Fast Stop operation
• CALL [Serial Comm Transmission Error] detection
• PID Sleep function (Y2-02 [Sleep Level])
• All Run commands and direction commands
If the drive has an applicable Run command from terminals when the drive was previously in Emergency Override
and the Emergency Override digital input is now OFF, the drive will respond as specified by S5-02 [HAND/AUTO
Switchover During Run] and S5-04 [HAND-OFF-AUTO Behavior].
During Emergency Override, the drive ignores the faults in
Mode = Fault Suppression]:
YASKAWA SIEPYAIH6B01A HV600 AC Drive Bypass Technical Reference
Table 5.64 when S6-07 = 0 [EMOVR Fault Suppression
5.11 S: Special Applications
5
397