Lightning Arresters P KVA P KVA. Description & Installation

Transcription

1 Lightning Arresters P KVA P KVA Description & Installation Printed in USA 09/11 TO330 Rev. B

2 Table of Contents Page 1.0 SCOPE PRODUCT OVERVIEW Intended Uses Lightning Arresters 18KVA, 10KVA kv Spark Gap PRODUCT FEATURES INSTALLATION Mounting Lightning Arrester Station Ground Connection Remote Ground Connection 3 General Information PHYSICAL CHARACTERISTICS Mechanical Configuration Environmental Requirements 5 Page 1

3 1.0 Scope This document describes the technical specifications, technical requirements and installation instructions for the P30027 and P30038 SNC Lyte Lynx Lightning Arrester packages. It provides an understanding of the basic functions and features available with these units. 2.0 Product Overview 2.1 Intended Uses The purpose of the lightning arrester is to protect the metallic shield of the CO/Remote cable and the isolation devices during lightning or fault conditions. When the voltage reaches the level of the arrester s discharge rating, the voltage will find a path to station ground rather than damaging the cable or isolation devices kV and 10kV Lightning Arresters SNC offers two models of Lyte Lynx Lightning Arresters. Since Lyte Lynx carries a continuous rating of 20kV, 60HZ, RMS as well as a 65kV impulse peak voltage, the 18kV model (P30027) is normally recommended. However, for installation where the dielectric condition of the incoming CO/Remote cable is questionable, the 10kV model (P30038) may be desired since GPR voltages rarely exceed 10kV, 60Hz, RMS maximum kV Spark Gap This feature allows termination of cable pairs for isolation transformer center tap drainage to provide protection for Class A service pairs whenever the lightning/surge arrester discharges. 3.0 Product Features The P30027 and P30038 use a non-shattering, polymer lightning arrester installed in an insulated housing. Each has a continuous kv arrester rating with a discharge voltage rating substantially lower than the tested 65 kv BIL of the Lyte Lynx system. During a lightning strike, the voltage potential difference between the CO/Remote cable shield and station ground is limited to the breakdown or discharge voltage of the arrester so that both the entrance cable and isolation equipment are protected. Mounted inside a fiberglass enclosure with a clear plastic protective cover, the arrester is normally installed near the CO/Remote cable entrance into the Lyte Lynx card shelf typically either directly below or alongside the shelf. 4.0 Installation CAUTION: To provide personnel isolation from local ground, stand on a thick rubber mat and use other adequate insulation devices (rubber gloves) when working on the Lyte Lynx system. Page 2

4 CAUTION: The incoming telephone pair(s) should be contained in insulated conduit (PVC, etc.), or the pair(s) should be jacketed with sufficient insulation to withstand a voltage rise from ground fault potential and from fault induction voltage. CAUTION: Any metallic shielding on the incoming CO/Remote pair(s) must be isolated from substation grounds all the way from the network low voltage interface (300 volt peak GPR point per IEEE Standard 487) to the entry into the Lyte Lynx. The conductors must also be isolated. 4.1 Mounting Lightning Arrester Drill holes in the back of the Lightning Arrester enclosure and securely mount to a non-metallic wall or backboard (use the backboard that the Lyte Lynx card cage is mounted to if backboard is large enough). Depending upon the space available, this can be to the left (looking at the front of the card cage) or just below the card cage. The Lightning Arrester may be mounted upside down to fit the situation. See Figure 1 for an example of how the lightning arrester is installed. 4.2 Station Ground Connection Connect a #6 AWG wire from the bus bar connector lug at the bottom of the arrester enclosure to station ground. Keep this wire as short as possible. See Figures 1 and Remote Ground Connection At the point where the cable would be centered in the Lightning Arrester enclosure, carefully strip off 4 to 6 inches of the cable jacket to reveal the cable shield. Open the cable shield by removing the center 2 or 3 inches of the exposed metallic cable shield. Try to do this without disturbing the cable pairs. Slip the cable through the PVC fittings on each side of the upper part of the enclosure. Holes in the PVC fittings allow the use of tie wraps (included) to secure the cable to the enclosure. Connect the wire attached to one end of the arrester to the CO side of the cable shield with a cable shield Bullit Bond (provided). Keep this wire from the cable shield to the arrester as short as possible avoid a large loop. Connect the wire attached to the 5kV spark gap to the station side of the cable shield - or with a separate wire - connect it directly from the spark gap to the ground terminal of the card shelf. See Figure 1. Page 3

5 General Information The above installation scheme meets the recommended protection practice of IEEE Standard remote ground outside the GPR zone of influence (300 volt GPR location) is accessible via a 5 kv spark gap located in the lightning surge arrester housing external to the card shelf. This installation scheme also provides for coordinated 65 kv BIL protection of both the isolation equipment (shelf and cards) and the dedicated entrance cable. The 5 kv gap coordinates drainage of surge voltage difference between the dedicated cable pairs and the shield should the power type surge arrester operate and equalize ground potential difference between station ground and remote ground via the cable shield. The isolation system is designed around the protection practice of IEEE Standard It is recommended that this configuration be used in any application environment where surges are possible. The BIL of the isolation system is assured and the dedicated cable receives similar BIL protection and insulation protection coordination between shield and cable conductors. Note: In some applications remote ground is directly needed for a circuit function such as for PBX ground start trunks (a less desirable trunk seizure configuration that is more prone to possible transient voltage and circuit noise problems than a loop start trunk). When a direct remote ground connection is required, a protection system application utilizing the 5kV spark gap must have the gap bypassed by one of the pairs to get central office ground directly accessible to the PBX card. This effectively disables the 5kV spark gap. Figure 2: 10KVA Lightning Arrester P30038 Page 4

6 Connect to Card Shelf Remote Ground Connect to CO Cable Shield Connect Station Ground to This Ground Lug Figure 3: Lightning Arrester Connections 5.0 Physical Characteristics 5.1 Mechanical Configuration Table 1: Physical Dimensions PART NUMBER HEIGHT WIDTH DEPTH P (36 cm) (54 cm) 7.10 (18 cm) P (28 cm) (38 cm) 5.30 (13.5 cm) 5.2 Environmental Requirements The Lyte Lynx Lightning Arrester system may be installed in an indoor or moderate outdoor environment and is guaranteed operable in temperatures ranging from 40ºC to 100ºC ( 40ºF to 212ºF) and under humidity conditions from 0 99% relative humidity non-condensing. Page 5

7 For further information or for technical support call or visit SNC Manufacturing Co., Inc. 101 West Waukau Ave., Oshkosh, WI or FAX Website: Page 6 TO330 Rev. B - 09/11