Honeywell SmartPAC 2 User Manual page 371

SmartPAC 2 with WPC Integration
It takes into account more factors (such as brake monitor setting, object sensitivity, and depth
penetration factor) than the OSHA formula. It has been developed specifically for guarding
of mechanical power presses. Both the ANSI and OSHA formulas are explained in the next
sections.
The ANSI Safety Distance Formula
DANGER
!
INCORRECT SAFETY DISTANCE
• Calculate the safety distance carefully according to the instructions below, and mount your
light curtain heads at least this distance from the hazardous area.
• Mount your light curtain heads at least 7.5" (191 mm) from the hazardous area, regardless of
the calculated safety distance.
• Be sure your value for T s includes the response times of all devices that react to stop the
press. If your measurement of stop time does not include response time of the press control,
light curtain, and any other devices that react to stop the press, the safety distance will be
too short.
Failure to comply with these instructions will result in death or serious injury.
DANGER
!
STOPPING TIME TOO LONG
Use a brake monitor where a light curtain is used to protect operators whose hands are
routinely exposed to a hazardous area, as required by OSHA 1910.217 (c) (3) (5).
A brake monitor continually checks that the machine's stopping time does not exceed a
predetermined limit.
Failure to comply with these instructions will result in death or serious injury.
This is the formula Honeywell Wintriss Controls recommends for calculating the safety
distance:
D s = K x (T s + T c + T r + T bm ) + D pf
D s is the safety distance we will find using the formula.
K is the OSHA-recommended hand-speed constant. This constant is 63 inches-per-second.
The hand-speed constant indicates how far you could theoretically move your hand and arm
in one second.
T s is the stopping time of a press in seconds. It is measured at approximately 90° of
crankshaft rotation (or at maximum closing velocity).
T c is response time of the press control. This is the time it takes for the control to activate the
machine's brake. In the 90° stop time test using SmartPAC 2, the stop time readout includes
the stop time of the press and response time of the press control. How to do the 90° stop time
test is described earlier in this chapter.
T r is response time of the light curtain. Response time for Shadow V is 30 milliseconds (50
milliseconds for 36" and 48" Shadow V light curtains)
SmartPAC 2 Run Mode Chapter 6
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