IDEC FS1A-C11S, User Manual

Page: 393 / 398

APPENDIX
A-5
A
P
P
E
N
D
IX
■ For ANSI B11.19
Use the following formula to calculate the minimum distance.
S = K × ( Ts + Tc + Tr + Tbm ) + Dpf
Tr = t1 + t2 + T1
Parameters
S: Minimum distance (mm)
K: Speed of the detected object or arm or leg entering the danger zone (mm/s)
However, the speed of entry K is not defined by ANSI B11.19.
Take into consideration various factors such as the physical ability of the operator.
The OSHA recommended value is K = 63 (inch/s)
≒
1600 (mm/s)
Ts: Machinery stopping time (s) as calculated from the last control elements (air valves, etc.) to
come to a stop
Tc: Maximum reaction time (s) of the machine control circuit required for operating the machine
brake
Tr: t1 + t2 + T1 (s)
t1: Reaction time of the SafetyOne (s)
t2: Preset OFF-delay time of the SafetyOne (s)
T1: Reaction time of the safety light curtain (s)
Tbm: Additional stop time allowed by the brake monitor (s)
If the machinery is equipped with a brake monitor, the following formula applies.
Tbm = Ta
– ( Ts + Tc )
Ta: Brake monitor set time (s)
(If the machinery is not equipped with brake monitor, it is recommended that 20% or more
of (Ts+Tc) become an additional stop time.)
Dpf: Additional distance calculated from the minimum detected object of the safety light curtain
(mm)
Dpf = 3.4 × ( d
– 0.275 ) (inch)
= 3.4 × ( d
– 7 ) (mm)
However, Dpf cannot be 0 or less.
In case of using the SafetyOne and a safety light curtain, the following parameter is used for the
above formula.
K = 63 (inch/s)
≒
1600 (mm/s)
Tr = t1 + t2 + T1 (s)
t1 = 0.04 (s)
t2 = 0 (s), 0.1 (s), 0.5 (s), 1 (s), 2 (s), 5 (s), 15 (s), 30 (s)
T1 (s) (Check the specifications of the safety light curtain.)