SNC offers two lightning arrester models - the P30027 rated at 15kV and the P30038 rated at 10kV. The 15kV model is normally recommended because the Lyte Lynx® carries a continuous rating of 20 kV, 60 Hz, rms as well as 65 kV impulse peak voltage. The 15kV arrester operates well below the 65 kV rating. However, for installations where the dielectric condition of the incoming CO/Remote cable is questionable, the 10 kV model may be desired because for practical purposes GPR voltages rarely exceed 10 kV, 60 Hz rms maximum.
The purpose of the lightning arrester is to protect the insulation system 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 between remote ground and station ground will be equalized rather than damaging the cable or isolation devices.
The P30027 and P30038 use a non-shattering, polymer lightning arrester installed in an insulated housing. The P30027 has a continuous 15kV arrester rating which has a discharge voltage rating (<40kV) substantially lower than the tested 65kV BIL of the Lyte Lynx® system. During a lightning strike, the potential voltage difference between the CO/Remote cable shield and station ground is limited to the breakdown or discharge voltage of the arrester, so that not only the entrance cable is protected, but also the isolation equipment. All models are furnished with a 5kV spark gap to limit voltage between cable pairs and shield of dedicated remote/CO cable.
The arrester is mounted inside a fiberglass enclosure which is normally mounted near the CO/Remote cable entrance into the Lyte Lynx® card cage. This could be directly below or alongside the card cage. The fiberglass enclosure has a clear plastic, protective cover.
For further information on Lyte Lynx® Lightning Arresters, refer to installation instructions T0330.