I was very proud of my first position as a biomedical/electrical specialist in a hospital. As an electrical engineer, I was attached to the Maintenance Department, and as a result, my office was in the basement next to all the support systems. The halls of the basement were normally quite at 6 a.m., but this day was different. The maintenance crew arrived early and were running between the Maintenance Department and the boiler room. Watching this unusual activity, I stopped the exasperated foreman as he was running by and asked what all of the excitement was about. He responded, “The boilers are down, follow me, I will show you.”
I quickly ran after him and looked down into the boiler room. Below, the maintenance crew were sloshing in about a foot of steaming hot water that covered the boiler room floor. Curious at what had happened, the foreman explained that the electrical controls had caught fire sometime in the night. Without controls, the boilers flushed their scorching hot water onto the floor as they internally overheated. The foreman added that a leaking steam pipe just above the control box could not be fixed until next the next summer shut-down. Until then, a bucket was placed on top the control panel to catch the dripping water. The guy who was responsible for watching the boiler was supposed to empty the bucket during his rounds. Unfortunately, that did not happen this one time.
“You have got to see this,” the foreman said as he motioned to follow him through the hot water to the other side of the boiler room. When he opened up the control panel, all I could see was a charred mess of a transformer and wires inside, due to a massive arc flash and resultant fire. As I looked into the darkened control panel, the foreman asked if I could fix it. Stymied but trying to help, I needed more information. I asked if he had any prints or circuit diagrams of the control panel. He did, and off to the maintenance room we ran. The foreman quickly found the “E”-size blueprint, which showed the control power for the steam system for all of the boilers. The input power as 480 V, three phase, to a transformer with a three-phase 120-V secondary that fed all of the 120-V solenoids throughout the hospital. After a quick review, I said I could fix it, and the maintenance crew jumped into action as I gave direction.
Just then, the phone in the maintenance department started ringing off the hook. The nurses were calling, concerned about the lack of hot water and the dropping temperature within the hospital. Even though the building was well insulated, the outside temperature was significantly below zero. The continual opening of the outside doors, as the first shift started coming to work, caused the temperature inside the hospital to drop.
At that point, the facilities manager said that if I could get power to the controls, he could very slowly back feed the domestic hot water tank into one of the smallest boilers. With a plan in place, I took charge of establishing control power. While standing in hot water, I made sure the circuit breaker for input power was open then followed up with my Simpson meter as a double check. I then used a hacksaw to cut the conduits that supplied 120-V power to the downstream controls. Again, I used my meter to ensure all of the 120-V wires were isolated from ground. Using a liberal amount of wire ties and tape, I then secured all of the feeders to a #12, three-stranded wire cord with a plug on the end. While standing in hot water, I plugged the extension cord into a 120-V outlet and was rewarded by the sound of the steam solenoids clicking. In the distance, I heard someone yell, “He’s got it!” My boss quickly followed by firing up the smallest boiler. After it came up to temperature, the next boiler was similarly back fed and started until all were on line and supplying heat to the cold hospital. Although the temperature had dropped in the hospital, life went on as normal and all hospital operations occurred on schedule.
It was quickly determined that the night time maintenance man had fallen asleep in my office and missed making his rounds. Therefore, he did not empty the bucket that captured leaking water from a steam pipe on top of the boiler control panel. During the night, the water bucket overflowed and spilled onto the control panel, which resulted in an arc flash and fire within the control panel. The hot water on the floor was due to a trash can that tipped over, spilling its contents and clogging the floor drains when the boilers flushed their boiling contents. After thorough evaluation of the situation, I decided to go back to college.
