Television Network Protects its Investment with UPS

Like any television network, the Christian Television Network (CTN), headquartered in Clearwater, Fla., risks losing broadcast capabilities during a power failure. But according to Chris Mavros, CTN's chief engineer, losing their viewing audience for a short period of time is not his greatest concern.

09/01/2002


Like any television network, the Christian Television Network (CTN), headquartered in Clearwater, Fla., risks losing broadcast capabilities during a power failure. But according to Chris Mavros, CTN's chief engineer, losing their viewing audience for a short period of time is not his greatest concern. "Because we don't run commercials on our station, the cost per minute is not that great to lose," he says. His primary concern is the damage to equipment caused by inconsistent power.

CTN uses tube-based transmitters, which are vulnerable to damage by power outages and cost tens of thousands of dollars per tube to replace. That's not a cost Mavros wants to bear, so he had a 300-kVA uninterruptible power supply (UPS) installed at the main facility and plans to upgrade all of their facilities with the same UPS in the near future.

All of CTN's transmitters are high-current devices with voltages in excess of 20,000 volts. The transmitters put out 60,000 watts of power, 24 hours per day. A power interruption shuts off the transmitter and stops cooling water flow. This is a non-standard shut down that dramatically shortens tube life.

CTN used smaller-capacity, battery-based UPS systems in the past for offices and studios, but not for their transmitters. When Mavros decided to look into installing UPS systems for CTN's transmitters, he recalled working with another station that had a larger, battery-based UPS system for its transmitters. "It did seem to cause problems at times, and that was a battery UPS, so I wanted to shy away from those."

Eventually, he chose a fly-wheel-based system over battery-based UPS systems in order to avoid problems, including the hassle and expense of replacing batteries every few years.

"What they're trying to do is keep from having a blackout and going off the air from small events, sometimes as short as 15 seconds," explained Curtis Thompson, a sales engineer with Ringhaver Equipment of Tampa, Fla. The UPS system's advanced power conditioning and flywheel energy storage provides this short-term power protection for CTN's critical load without the need for backup generators.

Other important factors that make the system suited to CTN's needs are: a small footprint to accommodate transmitter tower spaces; no requirement for air conditioning, as is the case with many battery-powered UPS systems; and no maintenance—an important factor since many of CTN's transmitter towers are unmanned.

CTN has six full-power stations. Four of these sites have transmitters at separate locations from offices and studios. At locations that house transmitters, offices and studios, in addition to keeping transmitter tubes in good condition, Mavros says, installing the UPS systems will lead to an overall improvement in productivity since some of the office equipment will also be backed up.

When asked whether CTN has had a need for their UPS system yet, Mavros said, "With that installed, we don't really know when we have power failure any more." He recounted a recent instance when he reviewed the UPS log and saw that the system recorded a power failure. "I guess we have had to use it; but if I hadn't looked at the log, I never would have known that we'd had a brief power interruption."

From Pure Power, Fall 2002





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