|
Hazard
Level |
Location
Type
|
||
| Unrestricted | Restricted | Controlled | |
| 1 | No requirements | No requirements | No requirements |
| 1M | Labeling, and Class
1* from connector, or connector requires tool |
Labeling | Labeling |
| 2 and 2M | Labeling, and Class 1* from connector, or connector requires tool |
Labeling | Labeling |
| 3R | Not permitted** | Labeling, and Class 1M* from connector, or connector requires tool |
Labeling, and Class 1M or 2M* from connector, or connector requires tool |
| 3B | Not permitted** | Not permitted ** | Labeling, and protected cables, and Class 1M or 2M* from connector, or connector requires tool |
| 4 | Not permitted** | Not permitted** | Not permitted** |
| *To be achieved
by mechanical design of connector, automatic power reduction (APR), or other
suitable means. **See 4.4.3. Where systems employ power levels of Class 3R or more, protection systems such as APR may be used to obtain the acceptable hazard level for the particular location type. |
|||
|
Table
I. Summary of engineering requirements at different types of locations
in optical-fiber communication systems. |