Lightning damage to electronic systems
Lightning is responsible for over a billion dollars in property damage every year, according to Underwriters Laboratories (UL). Lightning risk is a function of the area of a structure, the height and the number of strikes per year per square mile for the region. Churches are usually the tallest structure in a given area. In addition, a church may also have a bell tower or tall spire that can double the structure's height. This has given rise to the adage, "Churches attract more lightning than sinners."
Lightning damage is uncommon to Chime Master installations, but it can occur to any electronic device. We suggest that you unplug all connections, not only power, to all electronic products before major storms, especially if you are concerned about it or if you live in an area with frequent and/or severe electrical storms. As with any valuable equipment purchase, you should review your insurance policy to be sure that your bell ringing equipment is covered for fire, theft, vandalism or damage due to electrical storms.
Bell ringing equipment damage usually comes in on the AC power line. Our current products rarely suffer lightning damage of this type, except for an occasional blown fuse. Other voltage spikes electromagnetically coupled into the speaker line typically go no farther than the amplifier and the speaker drivers themselves. Speaker wiring should be routed on the opposite corner of the tower from the lightning and structural ground conductors. Long parallel wire runs essentially become a large transformer that can couple damaging spike currents from one to the other.
Bells hung on improperly grounded frames can receive high static charges that can dissipate through the electric ground wires. The purpose of electrical grounding conductors are to prevent shock hazards and they should never be carriers of high potential atmospheric charges. The spikes they carry to the electrical system can cause damage beyond the ringing equipment into sensitive (and expensive) computers, AV equipment, phone systems and other musical instruments.
Chime Master can provide additional surge suppression components for both ends of the speaker line to minimize damage to drivers and amplifiers. These components require a suitable ground at both the speakers and the amplifier. They work best when the speakers are mounted to a structurally grounded frame. Protection devices should be replaced every five years or immediately after a significant lightning event.
Metal framing within the tower structure needs to be bonded to an earth grounding rod, and the bell frame should be adequately bonded to the structural ground. Air terminals (lightning rods or strike termination devices) should also be used and bonded to the main conductor leading to the grounding rod.
If your building does not have any protection (no matter how low of a profile it is), you should have a certified lightning expert check your structure for adequate lightning protection.
All conductors and bonding should be regularly inspected and maintained by a Lightning Professional. Degradation of the grounding electrode over time by moisture and soil conditions is not something that can be visually checked, a high potential dielectric test set must be used. Any changes to the structure after installation of the protection system should be followed up with inspections of the modifications and an update to the protection system.
You can find more information on lightning protection from the following web resources.
- Lightning.org - The Lightning Protection Institute
- Importance of inspections
- Locate a certified Lightning Professional near you
- Lightning protection for churches (PDF download)
- National Fire Protection Association
- Electrical Installation Wiki (Schneider Electric)