Safety
Presence Sensing Devices
Light Curtains
OSHA Safety Distance Formula
The OSHA safety distance formula as specified in CFR Subpart O 1910.217 is as follows:
Ds = 63 x Ts
| Where | |
|---|---|
| Ds | Safety Distance |
| 63 | Is the OSHA recommended hand speed constant in inches per second |
| Ts | Is the total stop time of all devices in the safety circuit, measured in seconds. This value must include all components involved in stopping the hazardous motion of the machinery. For a mechanical power press it is the stopping time measured at approximately the 90º position of the crankshaft rotation |
| Note | The Ts number must include the response times of all devices, including the response time of the safety light curtain, the safety light curtain controller (if used), the machine’s control circuit and any other devices that react to stop the hazardous motion of the machinery. Not including the response time of a device or devices in the stop time calculation will result in insufficient safety distance for the application. This may result in operator injury. |