1128500
WPC 2000 User Manual
3-24
Initialization, Setup, and Checkout
The response time of the press control is included in the result of the 90° stop-time test run on
the WPC 2000 (see Determining the 90° Stop Time, page 3-17).
Response times of Shadow light curtains are shown in Table 3-3, page 3-21.
Calculation of the Tbm value is described in Calculating the Stop-time Limit, page 3-15.
Example: Calculating the Safety Distance for a Light Curtain Using the OSHA Formula
The OSHA formula is
Ds = K x Ts
The following value is a constant:
K = 63 inches per second
We will use the following values for the variables in the formula:
Stopping time of press + response time of press control = 0.190 sec. (result of the 90° stop-time
test)
Response time of light curtains = 0.059 sec. (Shadow 8 with 202 in. combined length including
extensions–see Table 3-3, page 3-21)
Additional time for brake wear = 0.035 sec. (see Example 2 in Stop-time Limit Calculation
Putting these values into the formula, we get:
Ds = 63 x (0.190 + 0.059 + 0.035)
Ds = 63 x 0.284
Ds = 17.89 in.
The light curtain must be mounted 17.89 in. away from the pinch point.
When using the OSHA formula, be sure to do the calculations in this order:
(1) Add the factors involved in the stopping time Ts first.
(2) Multiply the result by 63. This is Ds.
If you do no follow this order, your safety distance calculation will be incorrect.
Adding to Safety Distance for Blanking Windows
When using fixed or floating blanking windows with your Shadow 8 light curtain, you must
add a factor to the calculated safety distance for each beam that is blanked. This applies
whether you use the ANSI or the OSHA formula. For a one-beam fixed blanking window,
you must add 5.38 in. (136.6 mm) to the calculated safety distance (ANSI formula). You
OSHA SAFETY DISTANCE FORMULA FOR USE WITH TWO-HAND CONTROL
The formula for safety distance when using a Two-hand Control as a safeguarding device is similar
to the formula above, but does not include the response time of the light curtain. Use the following
OSHA formula for calculating the safety distance for a Two-hand Control:
Ds = K x Ts
As indicated above, Ts must include all factors that are involved in stopping the press, including
the response time of the press control but excluding the response time of the light curtain.
NOTICE
Summary of Contents for wpc 2000
Page 91: ...1128500 WPC 2000 User Manual 2 64 Installation ...
Page 191: ...1128500 WPC 2000 User Manual 5 22 Troubleshooting ...
Page 209: ...1128500 WPC 2000 User Manual A 18 Extracts from OSHA and ANSI ...
Page 225: ...1128500 WPC 2000 User Manual G 6 Glossary ...
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