IDEC FS1A Controller - Manual (Page 150)

7-5
■ 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
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.)