Diagram 2: ACS880-17/37 drives, frame R11
E-stop
button
Auxiliary
safety
relay
E-stop
safety
relay
Main
contactor
Charging
supply
contactor
Auxiliary
safety
relay
Diagram 3: ACS880-07 drives, frames n x R8i, 12-pulse variants with two contactors
(2 x AF2050)
E-stop
button
Auxiliary
safety
relay
E-stop
safety
relay
Main
contactor
Main
contactor
Note:
Only 12-pulse variants have two main contactors.
Diagram 4: ACS880-17/37 drives, frames nxR8i + nxR8i
E-stop
button
Auxiliary
safety
relay
E-stop
safety
relay
Charging
contactor
Auxiliary
safety
relay
Main
contactor
or main
breaker
Diagram 5: ACS880-07 drives, frames n x R8i with one contactor (AF1250 – AF2050)
E-stop
button
Auxiliary
safety
relay
E-stop
safety
relay
Main
contactor
■
Relevant failure modes
Relevant failure modes are:
•
the main contactor/breaker does not open when requested. (All contactor/breaker failures
are considered dangerous.)
•
internal failures of safety relays and the emergency stop button. These failures are
included in the PFH value of the function.
■
Fault exclusions
Fault exclusions (not considered in the calculations):
•
any short and open circuits in the cables of the safety circuit
•
any short and open circuits in the cabinet terminal blocks of the safety circuits.
■
Operation delays
Emergency stop total delay: emergency stop deceleration ramp time + 500 ms.
44 Technical data