Technical Guidelines for Installing, Maintaining and Inspecting Underground Telephone Systems.
Authors
Long RG; Chufo RL; Watson RA
Source
MISSING :77 pages
Link
NIOSHTIC No.
10001359
Abstract
This Bureau of Mines handbook covers the installation, maintenance, and inspection of telephone systems in underground coal mines and provides guidelines for the inspection and optimum use of mine pager phones. Various interconnection schemes and wiring distribution systems are discussed, along with such precautions as mounting and connection of cabling to provide strain relief and drip loops. Battery requirements and means of determining minimum useful battery voltage are reviewed. The problems and recommended practices for protecting pager phone equipment against such transients as lightning are discussed. The parameters affecting wire-size selections are discussed, including recommendations for insulation and construction of cable, including twisted-pair, figure-eight, and solid-conductor versus multiconductor wire. Instructions and examples of minimum wire-size requirements for a variety of telephone and system configurations are provided. The preferred methods of cable splicing for branching and repairs are identified and discussed. Internal self-testing of pager phone circuits involved using the pager phone to verify its own operational readiness, including operation of the talk circuits, page circuits, and listen circuits. Local measurement of battery condition and remote measurement of battery status are described.
Links with this icon indicate that you are leaving the CDC website.
The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
You will be subject to the destination website's privacy policy when you follow the link.
CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website.
For more information on CDC's web notification policies, see Website Disclaimers.
CDC.gov Privacy Settings
We take your privacy seriously. You can review and change the way we collect information below.
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookies used to make website functionality more relevant to you. These cookies perform functions like remembering presentation options or choices and, in some cases, delivery of web content that based on self-identified area of interests.
Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data.
Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. These cookies may also be used for advertising purposes by these third parties.
Thank you for taking the time to confirm your preferences. If you need to go back and make any changes, you can always do so by going to our Privacy Policy page.