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Altivar 71 gives fault “brF – Brake Fault” when brake contact feedback is from Mechanical brake. If same brake contact is from Brake control contactor, Altivar 71 does not give fault brF – Brake fault. Why

When Brake contact feedback is from Mechanical brake, it is a contact feedback that represents the mechanical brake actual status (OPEN or CLOSE). In most cases, mechanical brake contact changes when brake is completely engaged.
So, while stopping the movement, brake contact (Logic input configured as brake contact) feedback  from mechanical brake changes its state from CLOSE to OPEN only when brake is completely engaged and holds the load. This time equals the time taken by mechanical brake to CLOSE completely from complete OPEN state and it may vary from brake to brake.
To cope-up with this situation, Altivar 71 comprise expert settings for brake logic control which can only be accessed if LAC [ Access Level] is set to Expert.
Parameter “brH2 [ BRH b2]” to take brake contact into account for brake control sequence must be set 1 to avoid tripping on brF fault.
Following enabling brH2, user must set bEt [ Brake Engage time] at the least equal or higher than the time taken by Mechanical brake to CLOSE from OPEN state.
For example, observation says mechanical brake take 1 second to CLOSE from the instance it is commanded to CLOSE ( Command from Relay configured for Brake logic control) then bEt must be equals to 1 second at the least or higher than 1 second. To keep safe side, it is recommend setting it little higher side than actual time take by mechanical brake to operate.
If brake contact (Logic input configured as brake contact) does not OPEN before bEt time lapsed, drive will lock in fault brF
When Brake contact feedback is from Mechanical brake, it is a contact feedback that represents the mechanical brake actual status (OPEN or CLOSE). In most cases, mechanical brake contact changes when brake is completely engaged.
So, while stopping the movement, brake contact (Logic input configured as brake contact) feedback  from mechanical brake changes its state from CLOSE to OPEN only when brake is completely engaged and holds the load. This time equals the time taken by mechanical brake to CLOSE completely from complete OPEN state and it may vary from brake to brake.
To cope-up with this situation, Altivar 71 comprise expert settings for brake logic control which can only be accessed if LAC [ Access Level] is set to Expert.
Parameter “brH2 [ BRH b2]” to take brake contact into account for brake control sequence must be set 1 to avoid tripping on brF fault.
Following enabling brH2, user must set bEt [ Brake Engage time] at the least equal or higher than the time taken by Mechanical brake to CLOSE from OPEN state.
For example, observation says mechanical brake take 1 second to CLOSE from the instance it is commanded to CLOSE ( Command from Relay configured for Brake logic control) then bEt must be equals to 1 second at the least or higher than 1 second. To keep safe side, it is recommend setting it little higher side than actual time take by mechanical brake to operate.
If brake contact (Logic input configured as brake contact) does not OPEN before bEt time lapsed, drive will lock in fault brF
 
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