Fluke 875 manual Cable and Wiring Installation, Detector Cable Inside Containment

Installation

Installation 2

done until cable is pulled and tested. (Refer to the procedure Cable-877, in Appendix B, for more information.)

NOTE

Minimum bend radius of the 878-1-9 cable is four inches. When bending conduit or flex hose, take this into consideration. Typical bend radius for P/N 878-12-30 is ¾ inch; stainless steel flex house is 12 inches.

2.2 Cable and Wiring Installation

Detector Cable Inside Containment

Detector cables used inside containment are to be installed and terminated according to procedure Cable-877, in Appendix B. Do not allow any moisture or contaminants to deposit on the connectors used for installing cables due to the potential for electrical leakage. Because the detector transmits extremely small current signals, no terminal block connections are acceptable in the penetration. Signal conductor must be shielded but not grounded (qualified butt splices are acceptable). Refer to drawing GEL875-1 for electrical connections and to 878-1-9 for cable data.

CAUTION

The detector and readout must not be connected during the following test.

Detector Test After Installation

Testing of detector cables after installation is required. A leakage test from the center conductor to the shield should yield better than 1000 megohms at 1000 VDC.

Typical resistance of the center conductor is 0.022 ohm per foot at 20°C (68°F).

Detector Cable Outside Containment

Detector cables used outside containment should be a qualified coaxial type RG 59/U. Ideally, the cable should connect directly from the penetration to the appropriate connectors on Readout Module 876A-1. Terminal block connections and unshielded center conductors are not acceptable for installation. Fluke Biomedical recommends that cable 50-103 be used. Typical wiring is shown on drawing GEL 875-1. After installation, testing is required as described in the previous paragraph. Specifications for cable used outside containment are listed below. Refer to drawing 50-103 for additional data.

Specifications for Cable 50-103

Type	RG 59/U, alternate
Conductor	19/36 Tinned copper
Insulation	Cross-linked polyethylene
Flame Tape	Mica tape
Shield	#36 AWG, 92% coverage
Insulation Wrap	0.001 inch (0.03 mm) mylar
Jacket Type	Bostrad 7 (CSPE)

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