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4 Installation
4.1 To Determine a Safety Distance
The safety distance is the minimum distance that must be maintained between the light curtain and
the dangerous parts of the machine, so that the machine can be stopped before a human body or an
object can reach the dangerous parts .
In order to guarantee the operator's personal safety, the light curtain's installment position must meet
the requirements of the safety distance, otherwise a possible accident may occur.
Regarding the press which the slide can stop in the optional position, its safety distance Ds
computational method is given by the formula 1.
Ds = KT + C .............................. Formula 1
In the formula:
Ds---Safety distance, the unit is millimeter (mm);
K---Intrusion velocity of operator’s body or object, the unit is millimeter per second (mm/s);
T---Total response time of equipment, the unit is second (s);
C---Additional distance, the unit is millimeter (mm).
(2) K Value Determination
When the light curtain is installed in a horizontal position, taken as 1600mm/s for calculation.
When the light curtain is installed in a vertical position, and the safety distance is no longer than
500mm, taken as 2000mm/s; if the safety distance is longer than 500mm, then taken as 1600mm/s
for calculation.
(3) T Value Determination
The total response time of equipment T includes two parts, response time of the protector and
maximum halting time of the equipment.
The response time of the protector is given by the supplier.
The maximum halting time of the equipment needs to be measured.
(4) C Value Determination
Additional distance C is determined according to the distance that the operator’s hands enter the
light curtain and extend to hazard point by certain speed, until the protector is able to achieve
protection condition.
When the press is not used the self-lock (start - restart locking) function by the protector, according
to its examination precision, when calculating safety distance, should use the Table 4-1 stipulations
at least.
(1)
