Delta EB3000 Series User Manual page 78

4-9-1 Failure Rate of the Drive's Safety Function
Item
SFF
HFT (Type A subsystem)
SIL
PFH
PFD
av
Operation mode
PTI
DTI
Category
PL
MTTF
d
DC
NOTE:
As 1oo1 parts (SPS) and 1oo2 parts (STO), once any fault is triggered during operation, the drive
stops outputting current and keeps the drive in safe status.
4-9-2 STO Terminal Function
The STO (Safe Torque Off) function is to prevent the motor from producing torque force. It is run by
two independent hardware circuits to cut off motor drive's power module output in order to safely stop
the motor drive.
The following table describes the terminal functions.
Input / Output
Response time started from inputs are OFF until
the drive output stops
Phase deviation time between STO1 and STO2
Definition
Safe Failure Fraction
Hardware Fault Tolerance
Safety Integrity Level
Average frequency of
dangerous failure [h-1]
Probability of Dangerous
Failure on Demand
For elevator and machinery
Proof test interval
Diagnostic test interval
Category
Performance level
Mean time to dangerous failure
Diagnostic coverage
Item
Standard
IEC61508
IEC61508
IEC61508
IEC62061
IEC61508
IEC61508
IEC61508
IEC61508
IEC61508
ISO13849-1
ISO13849-1
ISO13849-1
ISO13849-1
Inputs: 2
STO input: STO1, STO2
Signal ON electric potential: 15–30 V
Signal OFF electric potential: 0–5 V
Output: 1
STO monitoring output SMO (SMO+, SMO-)
Less than 10 ms
Less than 110 ms
4-25
Chapter 4 WiringEB3000
Performance
99.68%
1
SIL3
SILCL 3
2.35 × 10
-9
3.08 × 10
-4
High demand
20 years
24 hours (STO)
10 msec (SPS)
Category 3
e
High
Medium
Table 4-14
Description
DC
DC
Table 4-15