Tales of disaster – Page 11 – Engineering Radio

Better Times at WICC transmitter site

The WICC transmitter site, Pleasure Beach in Bridgeport, has been cut off from normal access since the bridge to the island burned in 1996. Since that time, access has been by boat with a 0.93-mile walk from the dock to the transmitter building.

Last summer, LVI Construction, under contract from the Town of Stratford, put in a temporary road and began removing the burned out cottages. While that road is in place, the radio station has been able to access the site and get many important things accomplished. These include:

Replacing the vandal damaged top beacon on the South tower
Removing several decades worth of stored crap, garbage, obsolete and unused equipment
Repair the electrical service to the building
Replace the generator transfer switch
Repair the Sonitrol building alarm
Replace the old Onan Generator
Have the power company replace the 3-phase circuit from the point where the underwater cables come ashore to the transmitter building.

All of these projects should greatly improve the reliability of the station. This should make Bill, happy, who appears to have a WICC chip implanted in his brain because every time the carrier is interrupted he posts about it on the radio-info.com website.

The biggest issue with the site was the utility feed from the shore to the transmitter building. The original circuit was installed in 1936 when the station moved to the island. It was old and the poles were all rotting and had horizontal cross arms. Ospreys especially liked the horizontal cross arms as they made good nesting spots. That is, until the nest shorts out one of the phases catches on fire and burns the top of the pole off. This has happened several times over the years causing many hours of off-air time.

United Illuminating, the local utility company, was very cooperative and installed new utility poles, wires, breakers, and transformers, this time with a vertical phase arrangement, which should keep the Ospreys off of them. Additionally, the cottage removal project included installing Osprey nesting poles.

With almost all of the cottages now removed, the area looks much better than before. Actually, it should be a nice nature preserve, and hopefully, the absence of the buildings might reduce the number of vandals in the area. The work is almost done, so the road is about to be taken up. This means we need to wrap up the work out there, so the final push is on.

In the last three weeks, 10 truckloads of junk have been hauled out of the transmitter building and generator shack. Over 1,500 pounds of scrap steel, 640 pounds of insulated wire, 2,000 pounds of particle board furniture, old t-shirts, and hats (something called “Taste of Bridgeport” which, if anyone knows what that was let me know), old propane tanks, batteries, etc. We also managed to fix the fence and gate in front of the building and cut down the overgrown yew bushes and bittersweet vines.

The old Kolher transfer switch was also an issue. There was no place to mount a new switch inside and mounting one outside is out of the question, so the guts from the Kohler switch were removed and replaced with an ASCO unit. This was done in the summer of 2009. The breaker on the right side is the main service disconnect for the building, which was installed in September.

Onan 12JC 4R air cooled generator — Onan 12 KW 12JC 4R air cooled generator, removed from service

Today, it was time to replace the Onan propane generator. The old generator is an Onan 12JC-4R air-cooled propane unit which was installed on April 4, 1969, at a cost of $1,545.00. For many years, this unit gave reliable service, but it has many, many hours on it and it lacks the fault/self-control circuits needed for remote (read desolate) operation. Several times over the last few years, the generator would run out of gas or the propane tank would freeze up and the starter would crank until it burned out.

It was cold out on the island, with temperatures in the twenties and a bitter west wind blowing right into the generator shack. All of this conspired to make working conditions difficult. Wind chill readings were in the single digits all day long, and in spite of long johns and extra layers, by 3 pm I was shivering and even several hours after coming inside, I still felt cold.

The new generator is a Cummins/Onan 20GGMA which is rated for 20 KW. We used a John Deere bucket tractor to move the generator from the flatbed truck to the generator building, and then push it inside. The old generator wiring to the transfer switch was reused, but a piece of flex was used to connect to the generator instead of the solid conduit. The building fan was also wired up so that it would run whenever the generator was running.

The generator load with all possible things switched on and the transmitter running at full power is about 12,000 watts, but this would mean the air conditioner and tower lights were on during the daytime. More likely, the transmitter will be at low power when the tower lights are on and the AC will be intermittent on/off at night. At full load, this generator uses slightly less than 2 gallons of propane per hour. At half load, I’d estimate that to be 1.4 or so gallons.

HOCON gas came out and connected six 100-pound propane tanks in series, which should prevent tank icing. Propane weighs about 4.11 pounds per gallon, therefore the fuel supply should last about 100 hours, or 4.5 days, give or take. Why 100-pound tanks? Because we will have to shuffle them back and forth between the dock and the generator shed, a journey of about one mile, in a cart. Anything larger would be impossible to deal with. Even so, refilling the propane will be a 2 person job and will likely take all day.

The 100 amp fuse

I found this fuse in an old electrical panel that we were removing from the WICC generator shed. This was the original service entrance for the site as it was built in 1932 or so. The generator shed had a manual three pole two position transfer switch, which was fine back when a licensed transmitter engineer was on site whenever the station was on the air. The generator, according to the old records I could find, was an upright 2-cylinder slow-speed engine with a belt-driven generator. They were mounted on concrete pads about 5 feet apart. The motor had a big flywheel that was hand-cranked with the compression off. Once a good head of speed was built up with the hand crank, the compression lever was thrown and the engine would start. Alternatively, the procedure was tried again.

That was all replaced in 1971 when the transmitter site underwent a major upgrade. The old electrical service was bypassed and abandoned in place when a new meter and panel were installed in the transmitter building. The old service seems to have been frozen in time, untouched for forty years.

This fuse is a Kirkman Engineering Company and has a manufacture date stamp of January 1945. It is a replaceable link AKA “renewable” fuse. It has “peak lag” links, which I think would be called “slow blow” today. Peak lag may also indicate a large inductive load, which would lower the power factor. What I find interesting is that someone, once upon a time, placed two 100 amp links in parallel, then crossed the 100 AMP label out and wrote “200” on the fuse body.

The problem with this setup is that the panel and wiring were all rated for 100 amps. The wiring is #4 copper, and the transfer panel and switch are clearly labeled “100 amp, 3 pole.” It would appear that the finger stock holding the upper blade in place was loose, causing the fuse body to overheat. In fact, it became so heated that the case and the wood fiber holder were charred and missing.

Fortunately, there was never a fire.

The reason why we use properly sized fuses and breakers.

I Got The Air Conditioner Blues

Back in the day, when tube transmitters ruled the broadcast world, the common practice was to have a big cooling fan moving outside air through the transmitter building connected to a thermostat. Temperature swings of 30 to 40 degrees were common, however, the tube rigs could handle almost any temperature that didn’t melt plastic or freeze water.

Today’s solid-state transmitters are not that rugged. They like to have their rooms around 70 degrees +/- 10 degrees or so. Not to mention the other computer-controlled equipment commonly found at a transmitter site. Things like air chain processors, STLs, remote controls, etc. So, lots of air conditioning is the norm, and with lots of air conditioning comes lots of maintenance.

Air handler air filters need to be checked and replaced often. Condenser coils seem to attract every type of flying debris on the planet and need to be cleaned once, possibly twice per year depending on tree and weed species near the site. Even with preventative maintenance, occasionally things like this happen:

Of course, the entire cooling coil inside is frozen solid.

This condenser is low on refrigerant, causing icing problems. It has a slow leak somewhere and is about to be replaced. Other reasons for this happening are malfunctioning or non-existent low ambient kit on the condenser fan. Sometimes less than knowledgeable persons will install a 5-ton unit designed to run throughout the year but not take into account the effect of moving below-freezing air at high speed across the coils. Insufficient air moving across the cooling coil will also cause this. Insufficient airflow can be due to plugged air filters or clogged fan/blower blades.

This one is even better (same condenser unit):

The fan blade is sheared off and jammed into the condenser coil. This happened during power transfer from generator power to commercial power. Naturally, it was at 1 a.m. in the morning after a pole-mounted transformer had been replaced. When the building transferred back to commercial power, I went outside to use the “bathroom” before my two-hour drive back home. I thought I smelled something hot, you know that cooked paint/plastic smell, but couldn’t really track it down… the winds were kicking up and another thunderstorm was on the way.

The next afternoon, however, when the sun was up and the site was working on one air conditioner, the temperature alarm went off. Upon arrival, I found the condenser breaker tripped, resetting it caused the building lights to dim. The fan motor was shorted to the case. I would theorize the aluminum fan blade suffered from metal fatigue, likely because the blades were not balanced causing a vibration. When the power transfer occurred, there was just the right combination of torque and centripetal force to cause the blade to rip, and then lodge in the condenser coil.

The fan motor has been replaced, but I think it is time to replace the whole condenser unit, which will be expensive.

I found having a set of gauges to check the head pressure and suction is a good diagnostic tool to quickly pinpoint problems with HVAC units. This way, when the HVAC tech shows up, you can quickly point him in the right direction.

The breaker keeps tripping…

This is yet another addition of the “Burned up Sh*t” collection:

It is a breaker from a 5-ton AC compressor. Back in the bad old days when I was the Director of Engineering for a 28-station group Headquartered in Harrisburg, PA, I received a phone call from one of the local engineers. He stated that the studio AC unit compressor had burned out again and the breaker kept tripping. What did I think, asked him. I thought perhaps he should dig a little deeper and determine why the breaker was tripping before throwing another AC compressor at it. When are you coming to town again, he cheerfully inquired.

Okay, I get it.

I started by calling the HVAC company to inquire what had gone wrong with the compressors. Winding shorted to the case for both units was the answer received. It being July and mighty hot out, the various worker bees in the studio were feeling inconvenienced by the sweat in their eyes and dripping on their work, etc. I called the local manager and asked for a hotel room, I’d be up tomorrow. Then I called the HVAC guy back and asked in to meet me at the studio tomorrow afternoon.

Upon arrival the next morning, I found the fifth-floor studios to be hot, as reported. I trip to the roof location proved to be hotter still. I tested the voltages at the compressor unit with a DVM and everything looked good. A trip down to the utility room found the electrical panel in reasonable shape. Then the local engineering guy chimed in, “Oh yeah, I forgot to tell you, the breaker hums and gets hot when the compressor is on.”

It’s always that little bit of missing information…

I took the breaker out and sure enough, the fingers were all arched and nasty-looking.

I replaced the breaker, the HVAC guy showed up, with a new compressor and the studios began to cool off around 3 p.m.

Since then, I have specified Square D QO bolt-on breakers for new installations, especially for heavy loads like AC units, transmitters, and so on. They are a little more expensive, but in light of two AC compressors, the unscheduled trip out of town, and the grumbling staff, it is better to pay upfront for better equipment than to put up with preventable outages.