[Code of Federal Regulations]
[Title 7, Volume 11]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 7CFR1755.402]

[Page 484-486]
 
                          TITLE 7--AGRICULTURE
 
    CHAPTER XVII--RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE
 
PART 1755--TELECOMMUNICATIONS STANDARDS AND SPECIFICATIONS FOR MATERIALS, EQUIPMENT AND CONSTRUCTION--Table of Contents
 
Sec. 1755.402  Ground resistance measurements.

    (a) The resistance of the central office (CO) and the remote 
switching terminal (RST) ground shall be measured before and after it 
has been bonded to the master ground bar (MGB) where it is connected to 
the building electric service ground.
    (b) The ground resistance of electronic equipment such as span line 
repeaters, carrier terminal equipment, concentrators, etc. shall be 
measured.
    (c) Method of measurement. The connection of test equipment for the 
ground resistance measurement shall be as shown in Figure 1. Refer to 
RUS Bulletin 1751F-802, ``Electrical Protection Grounding 
Fundamentals,'' for a comprehensive discussion of ground resistance 
measurements.
    (d) Test equipment. The test equipment for making this measurement 
is shown in Figure 1 as follows:

[[Page 485]]

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    (e) Applicable results. (1) For the CO and RST, the resistance after 
the bond has been made to the MGB electric service ground shall not 
exceed 5 ohms. Where the measured ground resistance exceeds 5 ohms, the 
borrower shall determine what additional grounding, if any, shall be 
provided.
    (2) For electronic equipment, the ground resistance shall not exceed 
25 ohms. Where the measured ground resistance exceeds 25 ohms, the 
borrower shall determine what additional grounding, if any, shall be 
provided.

[[Page 486]]

    (3) When ground resistance measurements exceed the ground resistance 
requirements of paragraphs (e)(1) and (e)(2) of this section, refer to 
RUS Bulletin 1751F-802, ``Electrical Protection Grounding 
Fundamentals,'' for suggested methods of reducing the ground resistance.
    (f) Data record. Results of the CO and RST ground resistance 
measurements shall be recorded. A suggested format similar to Format I, 
Outside Plant Acceptance Tests--Subscriber Loops, in Sec. 1755.407 or a 
format specified in the applicable construction contract may be used. 
Results of the electronic equipment ground resistance measurements shall 
be recorded. A suggested format similar to Format II, Outside Plant 
Acceptance Tests--Trunk Circuits, in Sec. 1755.407 or a format specified 
in the applicable construction contract may be used. Data showing 
approximate moisture content of the soil at the time of measurement, the 
temperature, the type of soil and a description of the test equipment 
used shall also be included.
    (g) Probable causes for nonconformance. Refer to RUS Bulletin 1751F-
802, ``Electrical Protection Grounding Fundamentals,'' and 
Telecommunications Engineering and Construction Manual (TE&CM) Section 
810, ``Electrical Protection of Electronic Analog and Digital Central 
Office Equipment,'' for possible causes of nonconformance and suggested 
methods for corrective action.

[62 FR 23960, May 2, 1997]