by Ernest M. Duckworth Jr., P.E., President-LPGI & Affiliates

Sedalia, CO -- (ArriveNet - May 28, 2004) -- The typical E-911 dispatch center (PSAP) is an underground building beneath a very large tower. This tall tower is for the dispatch of emergency services and is also a very likely target for lightning. Personnel taking emergency calls coming into the PSAP must be at the phones at all times and do not have the luxury of remaining off during lightning storms, as recommended in virtually every telephone book in the country!

This places PSAP equipment and personnel at a significantly higher risk if additional precautions are not taken. Experience has shown that there is substantial damage to E-911 PSAP locations throughout the country, over a single lightning season! On the average, a single lightning strike will damage $45,000 in E-911 equipment and take approximately three weeks to replace. Those of you that do not think your PSAP's are experiencing lightning strikes may want to make a visit to some of your sites and listen to the personnel tell their 'war stories'!

In addition to finding that the tower and coax lines are usually not protected or grounded in accordance to recommended practices and procedures, the radio and E-911 equipment within the PSAP has not been properly isolated or grounded either. This allows lightning strike energy to spark all over the consoles, turning the room into a blue glow, (which is mentioned quite often) and damages much equipment in its path. Personnel have reported both electrical and acoustical shock quite frequently and dispatchers have been taken to the hospital from electrical shock to the face from their headsets.

Damage to E-911 equipment can be shown to be the result of ground potential rise (GPR) at the PSAP. A typical location with a radio tower experiences approximately 8kV to 20kV in GPR. This elevation of voltage potential in the PSAP ground plane is the result of lightning current (30kA to 200kA) passing down through the tower and into the grounding system of the building.

Why accept E-911 outages and potential harm to your dispatchers? Call LPGI & Affiliates and have a site engineering design review to correct current design deficiencies.

Go to web-site: www.lightning-protection-institute.com and complete the lightning checklist to determine your current susceptibility. Don't take the chance of potential harm to your dispatchers from a lightning strike.

LPGI & Affiliates
962 Coronado Drive
Sedalia, CO 80135-8303
303-688-5800
Fax: 303-688-5551