Specifications - State of Delaware

SECTION 260526 - GROUNDING: continued
M. Route grounding connections and conductors to ground and protective devices in shortest and
straightest paths as possible to minimize transient voltage rises.
N. Apply corrosion-resistant finish to field connections, buried metallic grounding and bonding
products, and places where factory applied protective coatings have been destroyed, which are
subjected to corrosive action.
O. Ground all wireway at least once and at 10-foot intervals.
P. Install insulated equipment ground conductor in all nonmetallic (and metallic) conduit.
Q. Bond non-isolated equipment ground conductors to each pull box, device box and junction box
through which they are routed.
R. Clean metal contact surfaces of clamp-on connectors to ensure electrical conductivity and
circuit integrity.
S. Ground all manhole hardware to manhole ground rods and connect to the underground duct
system ground conductors.
T. Provide each communication room backboard with a "Green" insulated ground wire that is
connected to the grounding electrode system, per J-STD-607-A. See Drawings for sizes.
U. All flexible power cords shall contain a green insulated equipment grounding wire.
V. Install isolated grounds where indicated.
3.03 FIELD QUALITY CONTROL:
A. Test ground resistance at each rod (before interconnection to other rods), the entire ground rodground
cable counterpoise system before it is bonded to building steel and the equipment listed
below. Test shall be witnessed by the Contracting Officer's Representative. Test with a DC
three-point earth ground resistance tester in accordance with IEEE 81. Measure ground
resistance without the soil being moistened by any means other than natural precipitation.
Where tests show resistance-to-ground is over values in Table 1 below, take appropriate action
to reduce resistance to the values in Table 1 by driving additional ground rods and extending
ground cables to the new rods; then retest to demonstrate compliance. Record and submit
results. The Contractor shall provide the following information at minimum to the Contracting
Officer. Method used, temperature humidity and general weather condition at time of test.
Table 1
Equipment to
Earth Ground
Resistance
Equipment
(Ohms)
Equipment operating
at 1,000V and higher 1
Transformers and substations less than 500 kVA 5
Transformers and substations 500 - 1,000 kVA 5
Transformers and substations greater
than 1,000 kVA 3
Pad mounted transformers 5
Manhole grounds 5
Other secondary neutrals and other grounds 5
Lightning protection grounds 1
Aircraft static ground receptacle 5
END OF SECTION 260526
260526-4 DEAN260526.DOC