Interesting chiller pictures and articles

A monthly publication of unique and interesting pictures and articles

Each month I will try to find an article or picture that interests the "Service Technician" as well as the "Manager/Owner". 

 

November 2011:  Copper...you need to protect your units investment:

As copper prices continue to rise, you will find that the outdoor condenser or chiller system becomes a target for vandals. the picture below shows just how fast someone can "borrow"  the coils.  This regretfully was done at a production plant, while the people were working inside.  Best to watch how easy your ground level units are to passers by.

 

 

August 2011: Learning how to wire a 3 phase motor; the correct way.

Regretfully an inexperienced electrician wired a 3 phase tower fan motor incorrectly.  The wiring was not incorrect for the voltage but completely incorrect for the line voltage to line wires. Somehow the windings received enough energy to run.  The RPM's were slow and the motor sounded as if the bearings were very worn (even though it was only hours old) It kept tripping the overload on the starter long after the electrician left the job.  We arrived to find the motor was nearly 300F and had already cooked the paint off of the TEFC motor within 6 hours of running.  (See picture).  fortunately we were able to correctly wire the motor, restart it and its quiet running kept the tower cool and with much less amperage and surface temperature.  NOTE:  Always check the running load amperage RLA and make sure it is close to is design and always double check wiring.

March 2011:  Springtime in Brooklyn...  "broken"  compressor

During a recent evaluation of a chiller system in a Brooklyn School, I found that the unit they were replacing had a few issues as to why the unit did not hold a charge or run. Yes what you are about to see is not edited and was truly found.  the hole you wee in the Copland compressor was not from a hit on the outside since there was no debris on the inside of the crank case.

 

December 2010    Iced evaporator in a 50 ton chiller

Back in December of last year a customer who did not treat the chilled water loop, as has lost two evaporators in the last 3 years, had a power outage and the standing water froze.  The below pictures show how the evaporator looked only one month ago and was cleaned and the second was the final findings of the frozen and ruptured evaporator.

              

 

March 2010

During an evaporative cooling tower inspection I came across a small rolling golf course.  This happens when there is no biological water treatment and the algae begins to grow.  In this case it is moss, and on a large scale.  It will eventually completely cover the water entering area and if it grows high enough it will stop the rotating manifold, causing overheating of the tower water.

            Movie for tower system

 

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January 2010

This winter has been particularly cold for the northeast.  I came across a situation where a customer's chiller was going off on the high pressure safety and could not understand why.  I asked him, over the phone some basic questions about his water tower and he said "everything is fine, I can't imagine that the water is too hot...it's 10F out side"  So out I went to see what I could do.  As I pulled up I saw a small glacier...and it was slightly larger than it should be ...even when it's 10F outside.

This was the cause of "a small water leak in each of the basins". 

NOTE:  the top of the pillars is 8 ft from the ground....to give you an idea of how much ice is under the snow.

 

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  March 1, 2008

This months article will only be a picture with an explanation...............

Subject:  When you have found that a fan motor is shorted but you can not find out the reason why.........

Look carefully for the- furry friend- on the top of the fuse block.......................This was found during a "routine"  preventative maintenance inspection.  Although the mouse did blow a fuse on the initial powering up of the unit, it did not have enough body mass to create the short again.  Note the 90 degree tail turn.

             

 

   January 15, 2007

This months article will only be a picture with an explanation...............

Subject:  When is it safe to use Schedule 40 PVC with a pressurized chilled water system?........  the answer is never, unless you would like to see what can easily happen.

Below is a few pictures of a customer ( plastics industry)  that choose to pipe the tower lines and the chilled water lines throughout the plant with SCH. 40 PVC...to cut on some of the installation costs.  This is not a good practice since the strength of SCH. 40 is weak compared to SCH 80 or copper line piping.  This is what happens when human error, which happens often enough, can cause serious downtime and lost revenue.

           

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November 9, 2008

This months article will only be a picture with an explanation...............

Subject:  When servicing a heat pump becomes too dangerous for even the experienced technician

Please note the "live" tenant watching if the work gets done on time.

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April, 2000

Posted on: 05/05/2000

Chiller maintenance tips from a pro

By Greg Mazurkiewicz / Greg Mazurkiewicz is new products/technologies editor.


Know your operating parameters for safe chiller operation. (Photo courtesy of Johnson Controls.)

Keep the System Running - and Don't Forget to Keep Safe.
 

chiller
Whether it's an older chiller or a state-of-the-art unit, maintenance is still a matter of the basics - like checking the oil in the compressor.

In his more than 50 years in the HVACR industry, John C. Schaub Sr. has seen and serviced more than a few chillers. He is still active as president of Schaub Consulting in Medford, NJ, while his son, John C. Schaub Jr., carries on his former business at John C. Schaub Inc., Mt. Laurel, NJ.

Schaub Sr. doesn’t hesitate to share his experience in the field. The following are some of his primary tips for technicians.

“The most important thing for compressors is the oil,” said Schaub, so the first thing he always does is check the oil. “Oil is essential,” he noted. The tech should take a small sample of the oil to check its condition.

“Make a visual check of the oil,” he said. “The darker it is, the more problems you’ll have.” Keep it clean.

On larger systems, Schaub recommends changing the oil once a year. Be sure to clean out any particles that may be in the bottom of the crankcase. “Over months of operation, you will pick up metal particles in the system.”

It’s also imperative to check the superheat. He explained that “Superheat is vital to the performance of the unit and to keep the compressor cool.” It’s important that superheat doesn’t rise and cause a problem with the compressor.

 

Give 'em some air
 
chiller
On larger chiller systems, Schaub recommends that the oil be changed once a year.

Schaub has also found that many companies “don’t have sufficient air circulating in the compressor room.” They’ll also put “barrels and trash in the room, so you can’t get to the unit. And a unit not seen is a unit that’s going to have problems.”

A lot of chillers in the field don’t have water gauges, stated Schaub. Usually, it’s the responsibility of the company purchasing the chiller to install water gauges so you can see pressure drops, particularly through the evaporator.

But many companies “don’t do what they’re supposed to do. They let it slide. And then, suddenly, they give us a call.”

If maintenance is done on a regular basis, a technician won’t have to come to the rescue. “On units that have proper maintenance,” he said, “your problems are almost zero.”

One recommendation that Schaub has long made is to put a bypass valve on the end of the pipe run going to the chillers to get the proper water flow. “It’s important to have the proper flow through the chiller tube bundles.”

He pointed out that you don’t want to have overflow through the tube bundle because then you get vibration, which can damage the copper tubes.

Schaub suggests telling your customers to check the compressor room every day. They should:

  • Look for oil around the unit; if there is any, they have a leak.
  • Check the sight glass with the unit on.
  • Check for compressor short cycling. And if they hear rattles or any change in noise levels, they should contact your company immediately.

These daily checks “can save a lot of grief.”

He also noted that “In the spring is when you have most of your problems with water towers,” particularly in the country where the farmers plow their fields, kicking up dust and dirt into the air, which gets into the towers and goes right to the condenser.

So you have to clean the condenser. With air-cooled systems as well, you have to clean to remove the dust.

“What causes refrigerant leaks is vibration,” said Schaub. “This is the biggest problem — around the compressor, on the lines, around the capillary lines.

“You need to check that you don’t have high vibration on a capillary line. If you do, secure it so it does not vibrate. That’s the most popular place where leaks are found.”

 

An explosive lesson
In 1967, Schaub was called to service chillers at a plastics plant. He had finished his work and was talking in the office with the plant manager. An explosion then shook the entire building.

In the rear of the plant there were tanks with a volatile liquid used in plastics production. A maintenance man had opened a tank valve and within seconds, the liquid contacted a steam pipe, causing the tank to explode.

Schaub was told to run for his life because a second explosion was imminent. Instead, he ran for his truck and $5,000 worth of equipment, because without the truck and equipment, he was out of business.

He didn’t realize that the plant next door was a gasoline refinery. If that would have exploded, the entire area would have been leveled. Unfortunately, two men did die immediately in the explosion, and the maintenance man died later.

The lesson here, noted Schaub, is to know what you are doing or else ask to be sure.

Mistakes can be deadly. The risks are high when you’re working with pressurized systems, power, and rapidly moving objects, such as found in compressors and fans.

Let’s be careful out there.

 

 

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The first hands on Chiller/HVAC/R troubleshooting handbook is out in publication. This is a must have book for you and your service technicians.  It will save you time and money along with passing on the vast knowledge of 60 years experience.

Click here for details

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