Mitsubishi Electric 800 Series Instruction Manual page 462

Protective function
• If one of the following faults occur while the brake sequence function is enabled, the inverter trips, shuts off output, and
turns OFF the brake opening request signal (BOF).
Fault
indication
When (Detection frequency) - (output frequency)  Pr.285 during encoder feedback control.
E.MB1
When Pr.285 (Overspeed detection function) = "9999", overspeed is not detected.
When deceleration is not normal during deceleration operation from the set frequency to the frequency set in Pr.282
E.MB2
(when Pr.284 = "1") (except stall prevention operation)
E.MB3 When the BOF signal turned ON while the motor is at a stop. (load slippage prevention function)
When more than 2 s have elapsed after the start command (forward or reverse rotation) is input, but the BOF signal
E.MB4
does not turn ON.
E.MB5 When more than 2 s have elapsed after the BOF signal turned ON, but the BRI signal does not turn ON.
E.MB6 When the inverter had turned ON the brake opening request signal (BOF), but the BRI signal turned OFF.
E.MB7 When more than 2 s have elapsed after the BOF signal turned OFF at a stop, but the BRI signal does not turn OFF.
NOTE
• During deceleration, inverter output is shut OFF when the frequency reaches Pr.13 Starting frequency or 0.5 Hz, whichever
is lower. For Pr.278 Brake opening frequency, set a frequency equal to or higher than the Pr.13 setting or 0.5 Hz.
• Pr.285 Overspeed detection frequency is valid under encoder feedback control (used with a Vector control option) even if a
value other than "7 or 8" is set in Pr.292 Automatic acceleration/deceleration.
• Setting Pr.278 too high activates the stall prevention and may cause E.MB4.
• E.MB4 occurs when the acceleration time from Pr.13 to
Pr.278 + Pr.280 reaches or exceeds 2 s.
Parameters referred to ???????
Pr.3 Base frequency page 591
Pr.178 to Pr.186 (Input terminal function selection)
Pr.190 to Pr.195 (Output terminal function selection)
Description
Brake opening request
page 415
page 370
(A) Application parameters
Less than 2s
Pr.278
Pr.13
Pr.280
(BOF signal)
PARAMETERS
Output
frequency
(Hz)
Time
ON
5
GROUP
A
461