Mitsubishi Electric 800 Series, Instruction Manual, Page: 462 / 727

(A) Application parameters
PARAMETERS
461
5
GROUP
A
 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).
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) page 415
Pr.190 to Pr.195 (Output terminal function selection) page 370
Fault
indication
Description
E.MB1
When (Detection frequency) - (output frequency)

Pr.285 during encoder feedback control.
When Pr.285 (Overspeed detection function) = "9999", overspeed is not detected.
E.MB2
When deceleration is not normal during deceleration operation from the set frequency to the frequency set in Pr.282
(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)
E.MB4
When more than 2 s have elapsed after the start command (forward or reverse rotation) is input, but the BOF signal
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.
ON
Time
Output
frequency
(Hz)
Less than 2s
Output frequency (Hz)
Pr.278
Pr.13
Brake opening request
(BOF signal)
Pr.280