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I have installed, started & commissioned Mitsubishi Citi-Multi Systems that have been in operation for 10 years. I can not speak to the reliability of other VRF systems. In my opinion, Mitsubishi...

May have got away with it using 22, but never with 410 & POE oil. We fix a lot of these after poor install. Purge with nitro during all pipe work. Triple evac & use ACCURATE micron gauge.
ONLY...

410a systems are even more prone to clogging LL driers.

APC, Stulz, Data Aire... All are inferior to Liebert in my opinion.
Also, in-row cooling designs are the way to go.
LIEBERT IS THE CADILLAC OF CRITICAL ROOM COOLING!

I have not seen that before, interesting. Must have a second contactor to run fan in opposite direction.

True, but there are several things that can be added. Air proving switch, freeze stat, low & high pressure switches, discharge line thermostats, phase monitors. All to protect the compressor.

Economizer would disable 1st stage mechanical cooling if outdoor conditions were suitable (sounds like they are) for free cooling. Suction line freeze stat on 2nd stage compressor or Low ambient...

Is it a semi-hermetic?

Tried to get guys to use this at our company, they were too OLD SCHOOL. I think these rings eliminate using too much Silfos on joints (a lot of techs do this to make sure no leaks). Also works very...

Carrier 38AKS condensing units with 2 fans do this too. #2 fan rotates backwards while #1 runs, when #2 is energized, it continues to run in wrong direction. A new capacitor fixes this.....for a...

Our company learned this the hard way too......MITSUBISHI'S ARE THE ONLY MINI SPLIT & VRF'S WE INSTALL NOW! CITY MUTI IS A GREAT PRODUCT.

Use a high quality electronic vacuum gauge (not your $100 variety). Gotta trust your tools!

Find the cooler gpm in the Manufacturers IOM book. There will be a minimum & maximum GPM graph where you can plot your FT./head. You will need to get cooler entering water psi & cooler leaving...

I have installed 3 of the City Multi systems- a great tip is to inventory your refrigerant tubing (lengths) & save the unused pieces from each branch line. Measure those left over pieces & subtract...

Just use a good recovery machine & keep recovery tanks cool.

Personally, I use my rubber gloves & leather protector gloves when I feel it is necessary. Mostly when I am working inside an electrical panel, motor starter control cabinet etc. Also voltage...

Burnouts in Heat Pumps are very troublesome because of the possibility of getting debris in the check valves, reversing valve etc. I would encourage the customer to replace the unit before heading...

I use Acid Away & install suction & liquid line replaceable core driers w/ HH cores. Run system for a couple days, remove suction core, replace liquid line core drier with standard core drier & run...

Time for a new RTU!

I was referring to the Challenger & Minimates. I have worked on the ICOM In-Row with digital scroll R410 & 407C. I have not been to the ICOM class yet.

Lieberts very good machines & are easy to work on.