The opening ceremony of the Summer Olympics in Beijing began on 8/8/08 at 8 seconds and 8 minutes past 8 pm (local time). Many weddings were scheduled for this date as it is considered to be a lucky number.

For the members of CCARA these numbers will be remembered for another reason! On Friday afternoon, 8 August 2008, an event occurred that will be (we hope) a one time occurrence.

Our repeater has the ability to notify users when normal power has been interrupted and the system is operating on battery backup. At about 5:30 P.M. we heard the repeater announce “Power Fail”. The warning was acknowledged and the system appeared to return to normal operation. No further power fail warnings were heard.

On Sunday evening about twenty minutes before the scheduled weekly net I discovered that the repeater was off the air. Attempts to remotely reset the system failed. Our club has trained operators to switch to simplex operation on the repeater output frequency during this type of situation. The net was conducted on 147.12 simplex with eight stations checking in to the net.

On Monday I scheduled a trip to the repeater site. On arrival the repeater was completely ‘dead'. The first thing I noticed was that the circuit breaker on the Polyphaser power line protector was tripped. Not wanting any surprises I turned off the repeater, repeater power supply and controller. The voltage on the battery backup was reading about 7 volts. The repeater had continued to work until the batteries were depleted.

I reset the Polyphaser circuit breaker. When nothing happened I went to the building circuit breaker panel. Yes, the circuit breaker for our circuit was tripped. Flip the breaker and Oh My! ! A violent response from the Polyphaser box. Both circuit breakers tripped again. We have a problem, Houston!

To make this story a little shorter (and keep under the 3 minute timer) we will jump to what really happened on Friday afternoon.

About one half mile from our repeater site there is a Dayton Power & Light substation. This substation is fed by high-tension wires that at one point cross over the local power lines. On 8/8/08 the arm supporting the top wire of the high-tension line broke dropping the wire on the lower high-tension line. This extra weight broke the lower support arm which allowed both high-tension wires to fall on the local power lines.

The resulting short allowed a huge voltage surge on the local power lines. I was informed that the voltage on the high-tension lines was approximately 345,000 volts.

At the repeater site this extreme voltage surge entered on the normal 240/120 circuits. The normal building circuit breaker panel allowed the surge to pass thru to the Polyphaser power line protector. The polyphaser recognized that this was a dangerous situation and shunted the surge to ground. The building panel then reacted to the ‘short to ground' and also tripped.

The repeater switched to battery backup and continued to operate normally with the added warning that normal power had failed.

The bottom line is that the Polyphaser power line protector preformed flawlessly and sacrificed itself to protect the repeater. We have already ordered a replacement.

So I will let you decide. Was 8/8/08 a lucky day for members of CCARA?

Submitted by: Paul, wb8zzr
08/15/2008