This post contains large amounts of angry hissing and swearing. You’ve been warned.
I was doing the weekly inspection checklist at the transmitter site when this….. Space Station Toilet….??? went thunk, plunk, and cycled out of Beam On. The display forlornly moaned of a low anode coolant flow alarm. I know the issue is with the flow sensor.
It’s in the middle of all this so I did not try to undertake the replacement single handedly. Look at this glorious mess!!!
But then my attention was drawn to the fact that it started getting warmer in the room… and it just kept getting warmer. Luckily, it was about 68 outside with a strong Delta Breeze, so I just opened all the doors and started to investigate the attempted thermal runway. On the roof I peeked into one of the large RTU (Roof Top Unit) air conditioners and saw a winter wonderland of ice. Hmm.
Not good. So why’s this thing icing up? It’s practically brand new! I called the HVAC company we have a service contract with and their dispatcher literally told me she was going to see if anyone felt like helping us out today. (No.)
Time to gather tools and investigate.
Definitely a low head pressure situation… but why? Remember, PV=nRT even for insufficient levels of T[emperature], so maybe it’s just running too cold due to low heat input into the system. Let’s open up the other side…
Note three things in this photo: 1) motor sheave spinning. 2) fan sheave barely spinning. 3) harder to see but— water flying everywhere including spraying on that poor little ABB drive!
Click, power down, go gather more tools, climb up and down the ladder about a zillion times…
I set the thermostat below to system off / constant fan and properly tensioned the belt, which DerpCo HVAC’s techs do not know how to do… At all… then restore power.
The fan didn’t start. The little ABB drive’s cooling fan wailed, but it just wasn’t coming on. Why? Finally on a whim I twisted the red and green thermostat wires together and it ramped politely up to full blast with no slippage. Guess the thermostat just isn’t letting constant fan be a thing. That’s fine…
Slowly but surely, the room temperature started creeping down.
I always wonder if I’d get in trouble for naming and shaming DerpCo HVAC. They’re a large, probably national company, and are far more interested with their prime directives of union busting and bumping out any employees with seniority than they are with providing proper service to their customers. I hate dealing with DerpCo mostly, though they have *one* tech locally who actually knows what they’re doing.