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HVAC near-misses and lessons learned

Just another day at the office…with a catch

December 2014

The day-to-day routine on any job can grow…well, kind of boring. It's the Same Old Stuff. But wise technicians know there are other times, when "same old" can change in an instant to threaten injury, or worse.

We wanted to hear what HVAC/R professionals have learned from their near-miss experiences, and share what they've seen with a wider Fluke audience. In a survey earlier this year we asked what happened, and what they learned.

HVAC safety equipment

Safety gear like this can help keep you safe as you work.

For Richard H, a commercial electrical contractor, it started with a problem in the sump heaters of a compressor that was off-line. "The unit had proper incoming voltage, but the sump heaters had only 265 volts AC, when they should have had full line voltage," he said.

"As I was checking the NC auxiliary contacts on the compressor starter, I thought that the correct supply power had been isolated and locked out," he continued. "Luckily I checked the aux contacts with my Fluke 116 and found that there was still power available from the operating compressor. That would have been a very rude surprise if I had not checked to ensure all sources of electricity were isolated!"

The data says "chill out"

Fluke 116 Digital Multimeter

With the Fluke 116 Digital Multimeter you can check whether power is present.

For data center engineer Peter G, the surprise challenge was to maintain his facility's cool when the heat was on.

"Lately we have had two separate cooling incidents…actually, heating incidents where we had insufficient cooling," he said. "In one, the water cooling system failed. The problem was, we weren't monitoring the cooling system, but only indirectly monitoring ambient temperature. When the temperature alarms went off at 90 degrees [F] we scrambled to cobble together ad hoc cooling with portable AC units and get a vendor to evaluate the failed cooling system." But the trouble wasn't over.

"The second incident was a similar temperature spike, this time in a hybrid storage space housing some network gear," Peter added. "We didn't have temperature monitoring in place and only on-site inspection identified the unusual temperature spike. Again, we scrambled to move in a portable cooling unit - and then implemented temperature monitoring."

Never assume!

The change in routine for HVAC/R technician Dan B was a shock, and a reminder.

"I walked up to a non-operating unit on a no-cool call," Dan recalled. "When I touched the unit to remove a panel I got shocked. A compressor had shorted to ground and the chassis was energized. There was no ground conductor installed. Lesson learned is to ALWAYS test the sheet metal on the unit for voltage prior to touching it, preferably with a FLUKE DMM, but at least with a FLUKE non-contact voltage tester. Never assume! It's the only life you've got!"

Fluke 1AC II A1 VoltAlert™ Electrical Tester

Use a non-contact voltage detector such as the Fluke 1AC-II, or a digital multimeter, prior to touching surfaces.

For Tony T, an electrical power and controls specialist, the change in routine hit especially hard - with a bit of luck thrown in.

"I was measuring voltage on the line side of the main breaker to a motor starter bucket in a 480V motor control center," he said. "I connected my leads wrong on my DMM and caused a short circuit at the probes, which caused an arc flash and blew me off my ladder. I suffered third-degree burns to my right hand. Luckily I was working in a hospital and went right to the emergency room for treatment."

A real hang-up

Clair Z, a school maintenance technician, would happily have returned to the old routine. But on a maintenance call to replace a part, he literally hit a snag. He couldn't go back.

"I had to go in a heating and cooling unit above a drop ceiling," he said. "Your hands had to be above your head and you had to lie down to replace the low limit. What I didn't know was when I was done my key ring went over the fan plate bolt…it kept me from moving to get out.

"The power was off but the heating water kept going through the unit. I could not move my hands to get to the keys. I was able to get my phone to call someone, who was not in building. With 130-degree water it did not take long to get hot in the unit. I was ready to pass out when help got there. One thing I learned: don't go in a tight place with your keys on your belt."

Thanks for the advice, Clair - and thanks to all who shared their lessons learned.