© Panasonic Industrial Devices SUNX Co., Ltd. 2017
18
Protection Area
[For use in the United States of America (as per ANSI/RIA 15.06)]
●
Equation 2
D
S
= K × (T
S
+ T
C
+ T
SF4B
+ T
bm
) + D
pf
D
S
: Safety distance (mm)
Minimum required distance between the sensing area surface and the danger-
ous parts of the machine
K
: Intrusion speed {Recommended value in OSHA is 63 (inch/s) [≈ 1,600 (mm/
sec.)] }
ANSI/RIA 15.06 does not define the intrusion speed “K”. When determining K,
consider possible factors including physical ability of operators.
T
S
: Halting time calculated from the operation time of the control element (air valve,
etc.) (sec.)
T
C
: Maximum response time of the control circuit required for functioning the brake
(sec.)
T
SF4B
: Response time of this device (sec.)
T
bm
: Additional halting time tolerance for the brake monitor (sec.)
The following equation holds when the machine is equipped with a brake monitor.
T
bm
= T
a
- (T
S
+ T
C
)
T
a:
Setting time of brake monitor (sec.)
When the machine is not equipped with a brake monitor, it is recommended
that 20% or more of (T
S
+ T
C
) is taken as additional halting time.
D
pf
: Additional distance calculated from the size of the minimum sensing object of
the device (mm)
SF4B-H
□
C
□ : D
pf
= 61.2mm
SF4B-A
□
C
□ : D
pf
= 129.2mm
D
pf
= 3.4×(d - 0.276) (inch)
≈ 3.4 × (d - 7) (mm)
d: Minimum sensing object diameter 0.985 (inch) ≈ 25 (mm)
SF4B-H
□
C
□
Minimum sensing object diameter 1.772 (inch) ≈ 45 (mm)
SF4B-A
□
C
□
<Calculation Example>
●
Calculation Example 2 For use in the United States of America
[OFF response time: 14ms or less, minimum sensing object diameter: 0.985 (inch) ≈ 25 (mm)]
D
S
= K × (T
S
+ T
C
+ T
SF4B
+ T
bm
) + D
pf
= 63 × (T
a
+ 0.014) + 3.4 × (d - 0.276)(inch)
= 63 × (T
a
+ 0.014) + 3.4 × (0.985 - 0.276)
= 63 × T
a
+ 63 × 0.014 + 3.4 × 0.709
= 63 × T
a
+ 0.882 + 2.4106
= 63 × T
a
+ 3.2926
≈ 63 × T
a
+ 3.29 (inch)
In case this device is installed in a system with a maximum halting time of 0.1 (sec.)
D
S
= 63 × T
a
+ 3.29
= 63 × 0.1 + 3.29
= 9.59 (inch)
≈ 239.75 (mm)
Hence, as per the calculations D
S
is 239.7 (mm).
<Reference>
● When the floating blanking function is applied, the minimum sensing object becomes large.
According to ANSI B11.19, Dpf = 900mm (3 ft) when d > 64mm (2.5 inches).
● Since the calculation above is performed by taking 1 (inch) = 25.4 (mm), there is a slight differ
-
ence between the representation in (mm) and that in (inch).
Refer to the relevant standard for the details.
