Hitachi WJ Series User Manual page 201

Chapter 9
Protection function when using encoder feedback
A
 When encoder feedback is enabled, the following protective functions are available. Please use
according to the intended application.
Code
[P015] Creep speed
Over-speed
[P026]
detection level
Speed
[P027] deviation error
detection level
Encoder
[P077] disconnection
timeout
[C021]
Output terminal
[C022]
function
[C026]
■ Over-speed error detection
 If the feedback detection speed exceeds the "Over-speed detection level [P026]", the inverter
will trip with an "Overspeed error [E81]". Set this to the maximum speed of the intended
application.
This function is enabled when "Pulse input, target function selection [P003]" is set to "Speed
feedback (01)", and [P026] does not equal 0.0.
■ Speed deviation error detection
 If the absolute value of speed deviation (output frequency - feedback detection speed) equals or
exceeds the "Speed deviation error detection level [P027]" during operation, the " Speed over
deviation [DSE] (22)" output turns ON. The inverter does not trip at this time. To enable this
function, assign the [DSE] terminal to the output terminal, and set [P027] to a value other than
0.00.
■ Encoder disconnection detection
 If the output frequency equals or exceeds the "Creep speed [P015]" and the feedback detection
speed is less than the "Minimum frequency [b082]" for the duration of the "Encoder
disconnection timeout [P077]", the inverter will trip with an "Encoder disconnection error [E80]".
If a false detection occurs due to heavy loads and a slow startup, adjust [P015] and [P077]
according to the intended application.
Item
Low operation speed before positioning in
simple position control is complete, and the
speed of encoder disconnection detection
judgment.
A trip will occur with an "Overspeed error
[E081]" if the feedback detection speed
exceeds the over-speed detection level
multiplied by the maximum frequency setting
when [P003] = "Speed feedback (01)".
This setting is disabled if this is set to 0.0.
Sets the level at which excessive speed
deviation is detected.
Sets the time to detect an encoder
disconnection. Disconnection detection is
disabled if this is set to 0.0.
Speed over deviation [DSE]:
The [DSE] signal turns on when the
following conditions are met during
operation.
| [d001] - [d008] | ≧ [P027]
Description
9-5-17
Inverter Functions
Data
Minimum frequency [b082]
to 10.00 (s)
0.0 to 150.0 (%)
0.00 to 120.00 (Hz)
0.0 to 10.0 (s)
22