Banner DUO-TOUCH Run Bar with STB Buttons - Manual (Page 5)

U.S. Applications
D
s
the Safety Distance (in inches)
K
the OSHA/ANSI recommended hand-speed constant (in inches per second), in most cases is calculated at 63
in/sec, but may vary between 63 to 100 in/sec based on the application circumstances
not a conclusive determination; consider all factors, including the physical ability of the operator, when
determining the value of K to be used
T
h
the response time of the slowest hand control from the time when a hand disengages that control until the
switch opens
T
h
is usually insignificant for purely mechanical switches. However, T
h
should be considered for safety distance
calculation when using electronic or electromechanical (powered) hand controls. For Banner Self-checking
Touch Buttons (STBs) the response time is 0.02 seconds
T
m
the maximum time (in seconds) the machine takes to cease all motion after it has been tripped. For full
revolution clutch presses with only one engaging point, T
m
is equal to the time necessary for one and one-half
revolutions of the crankshaft. For full revolution clutch presses with more than one engaging point, T
m
is be
calculated as follows:
T
m
= (1/2 + 1/N) x T
cy
N = number of clutch engaging points per revolution
T
cy
= time (in seconds) necessary to complete one revolution of the crankshaft
T
r
the response time of the Safety Controller as measured from the time a stop signal from either hand control.
The default Safety Controller response is 0.0xx seconds, plus any additional closed-to-open debounce time. If
the debounce time is adjusted, the time in excess of xx ms (default closed-to-open debounce time) must be
added to the stated response (see Specifications).
T
s
the overall stop time of the machine (in seconds) from the initial stop signal to the final ceasing of all motion,
including stop times of all relevant control elements and measured at maximum machine velocity
T
s
is usually measured by a stop-time measuring device. If the specified machine stop time is used, add at
least 20% as a safety factor to account for brake system deterioration. If the stop-time of the two redundant
machine control elements is unequal, the slower of the two times must be used for calculating the separation
distance
European Applications
The Minimum Distance Formula, as provided in ISO 13855:
S = (K x T) + C
S
the Minimum Distance (in millimeters)
K
the ISO 13855 recommended hand-speed constant (in millimeters per second), in most cases is calculated at
1600 mm/sec, but may vary between 1600 to 2500 mm/sec based on the application circumstances
not a conclusive determination; consider all factors, including the physical ability of the operator, when
determining the value of K to be used.
T
the overall machine stopping response time (in seconds), from the physical initiation of the safety device to the
final ceasing of all motion
C
the added distance due to the depth penetration factor equals 250 mm, per ISO 13855. The ISO 13855 C
factor may be reduced to 0 if the risk of encroachment is eliminated, but the safety distance must always be
100 mm or greater
Example Separation Distance Calculation
The following example illustrates the use of the formula to calculate separation distance for a part-revolution clutch
machine. This example uses 0.50 seconds as a typical value for T
s
and 0.035 seconds for T
r
and 0.020 seconds for T
h
:
STB Self-Checking Optical Touch Buttons
P/N 64136 Rev. C www.bannerengineering.com - tel: 763-544-3164 5