Hello there.
How is maintenance structured at your site?
I mean, how is the interaction between maintenance, operation and Planning department?
Who's " the boss"?
Does Operation have the autonomy to allow or not a maintenance service to happen?
Does planning dept plan activities without...
Hello there,
What are acceptable ranges of current unbalance in three phase motor?
Considering:
current unbalance = (max deviation from average current) / average currrent
I have this motor that powers a pump:
R=87 A
S=91 A
T=88 A
AVERAGE = 88,7 A
MAX DEVIATION FROM AVERAGE = 2,3 A
CURRENT...
If positive displacement compressor (such as scroll) has constant flow no matter the resistance in the system, how can TXV control flow?
Or it doesn't?
I have a system with several fancoils with pressure independent balance and control valve (IMI HYDRONICS TA FUSION-P 50)
However, some of them are showing strange behavior:
In automatic mode, at some point during operation, even though valve actuator is fully open there is no flow, so...
Hi there guys,
In which type of operation (parallel or primary/backup) will chillers and pumps last longer?
As:
Parallel = more working hours more less stress
primary/backup = less working hours / more stress
Hello there,
I'm doing a study on hotel's chiller sizing and I'm looking for a typical hotel room hourly occupation profile.
That is:
From all room that were sold, how many are actually occupied (guest is inside the room), for every hour of the day?
Example:
- 11a.m. = 20% (100 sold rooms...
Hello there,
It is known that NPSHr provided by manufacturer is measured as the point at which the differential head drops by 3%.
Therefore, it doesn't necessarily means that it will (100% for sure) cavitate when NPSHa < NPSHr.
But why is NPSHr is measured like this?
Why in fact cavitation may...
How to determine reference pressure and its location in a closed loop pumping system without tank?
I've drawn a really simple layout so we can work on it.
Imagine a system basically composed by a pump and 2 heat exchangers located 10 meters above pump. No openings to atmosphere and no...
If i'm using a centrifugal fan to extract air frmo a battery room, and I place it above room's ceiling (thus outside explosive atmosphere), does this fan need to be explosion proof? If yes, why?
Hello there,
I have this 17m² office room.
Air is cooled by 18000 BTU/h split AC unit.
Outdoor air is supplied at 20 liters/second.
Is extraction, in this case, really necessary?
Hello there,
So this power plant has this exhaust system working for 10 years. They bought the fan design project and built it themselves.
Fan specs (design):
770 rpm
194 bhp
183 kgf.m
146.000 m³/h
Motor specs
6 poles
250 hp
148 kgf.m
nominal amps 340A
Pulley specs
600mm - 390mm
They don't...
Hello,
So we have a Motor Control Center with big VFD's.
Those equipments altogether create more than 250.000 BTU/h of dissipated power.
Currently we have 4x 60.000 BTU/h split air conditioners to cool the MCC down. The panels have built-in exaust system and we've built a collecting duct...
