Hi Guys!
I had one of those days a couple of weeks ago.
Where I was sent to do a "Look and Log!" Maintenance visit, on a site I rarely visit.
Easy Day I thought!
Logging a York Recip Chiller and a Carrier Screw Chiller.
Met the customer (Happy with his plant!)
Start logging the 2 recip (8 stages of Loading) York and immediately suspect an issue.
As the 2 comps were running on 2 and 1 stage of loading both discharge limiting.
Water temp at 12c setpoint at 9c. With an 8c split across the water cooled Condenser.
shut 1 comp down to try and load the remaining up!
Nightmare!
Whatever I did I could not stop either overshooting and tripping on HP.
17 bar unload and 18bar trip.

I reluctantly called the customer down to the plant room and explained that his "Nicely Running Plant" was sick and that I was convinced his water circuit was blocked.
The primary Pump Suction was approx. 10 psi. which was low according to the site Maintenance Engineer.
On returning from checking and cleaning the strainers on his Evaporative Cooling Tower.
He confirmed my suspicions were correct and showed me a handful of plastic bits!
Smiling further,He then produced in the other hand a Mobile phone Battery!
I kid you not!
Apparently sat in the strainer was this plastic clad mobile battery.

Well Pump Suction pressure now 20psi and split across condenser now 3/4c.
A few more adjustments and the chiller was not only running balanced.
But reaching set point and cycling off!

The Carrier also had some Issues but that's another story!
My day got better and We had a happy customer!

Result!
Grizzly