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Section 49 – Signals, Lighting and Electrical Systems

overlap the spring connector and detector lead-in cable at least one and one-half inches (1-

1/2”). The tape sealant shall be Thomas and Betts Catalog No. HSTS25 or approved equal.

The Contractor shall then apply heat-shrink tubing over the splice. Heat shrink tubing shall

be medium or heavy wall thickness irradiated polyolefin tubing containing an adhesive mastic

inner wall. Minimum wall thickness prior to contraction shall be 0.04 inch. When heated, the

inner wall shall melt and fill all crevices and interstices of the object being covered while the

outer wall shrinks to form a waterproof insulation. Each end of the heat-shrink tube or the open

end of the end cap of heat-shrink tubing shall, after contraction, overlap the conductor insulation

at least one and one-half inches (1-1/2”). Heat shrink tubing shall conform to the requirements

of UL Standard 468D and ANSI C119.1, for extended insulated tubing at 600 volts. The

Contractor shall use the appropriate size heat-shrink tubing from the following Thomas and

Betts Catalog Numbers HS6-1, HS6-1L, HS4-30, HS40-400 or equal product if approved by the

All heat shrink tubing shall meet the following requirements:

33 percent, maximum, of supplied diameter when heated to

125°C and allowed to cool to 25°C

Dielectric Strength:

350 kilovolts per inch, minimum

ohms - centimeter, minimum

2,000 lbs. per square inch, minimum

Operating Temperature: -40°C to 90°C (135°C Emergency)

0.5 percent, maximum

When three (3) or more conductors are to be enclosed within a single splice using heat-

shrink tubing, mastic shall be placed around each conductor, prior to being placed inside the

heat-shrink tubing. The mastic shall be the type recommended by the manufacturer of the heat-

Heat-shrink tubing shall not be heated with an open flame. A heating device designed for

the purpose is required. Immediately after heating the splice and while the internally-applied

sealant is still liquid, the open end of the splice shall be clamped together until the sealant dries.

If any detector lead-in splice fails within one (1) year due to poor workmanship, the

Contractor shall replace all detector lead-in splices made by the Contractor within said

Where shown on the Plans, detector loops shall be sawcut into detector handholes.

Detector handholes shall be installed in accordance with these Specifications and as shown on

the Standard Drawings unless otherwise specified or directed by the Agency. No splicing will

be permitted in the detector handholes.

Conduit from the detector handhole to the adjacent pull box shall be sized as shown below: