Functions, monitoring, and protective functions
9.2 Drive functions
Bypass as a fallback strategy
If the converter fails due to an internal, non-acknowledgeable fault, essential service mode is
no longer possible. In this case, the motor can be operated via the controller in bypass mode
in the event of converter failure. For this purpose, bit 7 of the status word for the automatic
restart (r1214.7) must be interconnected with p1266.
The bypass function must also be activated without synchronization (p1260 ≠ 3), and the
changeover source for the bypass must be set to "Bypass via signal (BI: p1266)"
(p1267 = 1).
You must ensure that r1214.7 is also set, otherwise there will be no changeover to the line
supply. To end the bypass mode, the essential service mode must be deactivated. There is
no switchover to converter operation (drive coasts down).
Behavior in the event of an encoder error
When operating in vector control with encoder in the essential service mode, there is an
automatic switchover to sensorless operation and movement of the drive continues in the
event of an encoder error.
Display of activations/faults of essential service mode
The number of activations and the errors that occurred during essential service mode are
displayed in parameter r3887:
● r3887[0]: Number of activations of essential service mode
● r3887[1]: Number of faults during essential service mode
The counter statuses in r3887 can be reset with p3888 = 1.
Function diagram
FP 3040
FP 7033
Parameters
• p3880
• p3881
• p3882
• p3883
• p3886
• r3887[0...1]
• p3888
• r3889.0...10
442
Setpoint channel - Direction limitation and direction reversal
Technology functions - essential service mode (ESM)
BI: ESM activation signal source
ESM setpoint source
ESM alternative setpoint source
BI: ESM direction of rotation signal source
CI: ESM setpoint TB30/TM31 analog input
ESM activations/faults, quantity
ESM activations/faults, reset quantity
CO/BO: ESM status word
Inverter chassis units
Operating Instructions, 07/2016, A5E00331449A