Wintriss SmartPAC 2, User Manual, Page: 397 / 604

SmartPAC 2 with WPC 2000 Integration User Manual 1128600
Extracts from OSHA and ANSI A-3
(d) Muting (bypassing of the protective
function) of such device, during the
upstroke of the press slide, is permitted for
the purpose of parts ejection, circuit
checking and feeding.
Top of stroke is the point at which muting shall
cease as it is not possible to set a point on the
downstroke as the exact position where the
hazard of die closing starts.
(e) The safety distance (Ds) from the
sensing field to the point of operation shall
be greater than the distance determined by
the following formula:
Ds = 63 inches/second x Ts, where
Ds = minimum safety distance (inches);
63 inches/second = hand speed constant;
and
Ts = stopping time of the press measured
at approximately 90° position of crankshaft
rotation (seconds).
Safety distance represents the distance an
operator can move his hand during the time it
takes a press to stop. The internationally
recognized hand reach speed is 63 inches/
second.
To determine this safety distance, the stopping
time of the press is measured with some
appropriate measuring device. The
measurement is taken such that the stop signal
is given to the press at the 90 degree point of
the crank position.
Since some stopping time increase must be
accommodated due to braking system
deterioration, a percentage factor must be
added to the measured time to obtain the factor
for use in the equation for determining safety
distance. A percentage factor of 20% is
recommended for presses with new brakes or
brakes of good condition. For older brakes, a
10% factor is recommended.
Example:
Measured stopping time = 0.190 seconds
Time factor = 1.2 x 0.19 = 0.228 seconds
Calculation = 63 x 0.228
Safety distance = 14.4 inches
(f) Guards shall be used to protect all areas
of entry to the point of operation not
protected by the presence-sensing device.
(3) (iii) (f) Great care must be taken to assure
that no access to the die area exists unguarded.
OSHA 1910.217 (c) (3) (5)
(5) Additional requirements for safe-guarding.
Where the operator feeds or removes parts by
placing one or both hands in the point of
operation, and a two hand control, presence-
sensing device, Type B gate or movable barrier
(on a part revolving clutch) is used for
safeguarding:
This paragraph tells the condition under which a
brake monitoring system is required after
November 1, 1975.
(i) The employer shall use a control system
and brake monitor which comply with
paragraphs (b) (13) and (14) of this section.
This requirement should be complied with by
November 1, 1975.
(b) (13) Control reliability
(b) (14) Construction requirements.
Extracts from OSHA Regulation 1910.217
OSHA Regulations PMA Interpretation