Troubleshooting a chiller issue today 

After 2 years of residential, about 4 months ago I finally made the jump to a commercial/industrial company. I’m still pretty new to this huge stuff too. The shear size and enormity of some of this equipment is mind blowing to me. My first week at this new job I went with a senior tech to change some belts out on a 60 ton Carrier “boxcar” unit. I said “holy shit this unit is huge” to which he laughed and replied “this is nothing, you haven’t seen anything yet… this is one of the smaller ones!” This boxcar unit was the size of a double wide mobile home. 🤣

So 15 years in the residential hvac field but now just switched to working for a college doing hvac… I feel your pain on chillers , it’s a daily struggle for me but hopefully in a year I’ll be all good!

After working for years on big commercial equipment, working once in a while on residential equipment feels like playing with toys 😂

Welcome to the heavy side Bud glad to have you. I would have really been interested to see how the sensor calibrations were doing on the chiller itself. Whether or not any of the thermistors or transducers we're starting to get out even if intermittently.

it’s fun to learn this stuff! I inherited a building with two broken chillers, rotted out air handler(s), rotted evaporative condenser and pneumatic controls which didn’t even function. And I don’t do HVAC as a profession, but I’m an engineer and can learn. I’ve learned an absolute ton about chillers, boilers and building automation, but I feel like i’m barely scratching the surface. The fun part is that this building is kind of like my personal lab to learn and try shit. Enjoy learning, dude! it’s a blast.

Personally I would have checked the strainers on the chd water loop and measured any pressure drop! Then carried out full running log. Of Chiller on full load to determine efficiency of chiller 👍🏻 Interesting video 🇬🇧🇬🇧🇬🇧

Nicely done Bill! Good to see someone else doing this stuff, always interesting with larger equipment, hope the new job is treating you well. Keep up the good work 💪

Good stuff Bill, easy to get over whelmed but you got the smarts to get through it. Keep your head up. I’m in the same boat

Great little vid Bill ... Thx for sharing ...

There are what’s called Pete’s plugs on the side of the chill water lines. Remove the caps and check the temperature drop across the heat exchanger. Push your thermometer in the hole. It should be around 11 or 12 degrees difference. The air bleeders should be at the highest point of the chill water lines. The cavitation of the pressure gauge and the sound I was hearing makes me think air is in the lines. Did you lose power? This can cause this. You are converting to electronic controls. Much better than pneumatic controls. In my opinion. You should check out the old starters on the wall the VFDs replaced. On the overloads at the bottom you will see the heaters. They will have a letter and then some #s. On the door you will see the ratings for the starter. Pretty neat I think. I still have a bunch in the field. I heard a buzzing in the first room that sounded like a starter with issues. Have fun learning the big stuff. Hit me up if you ever need help. Stay safe.

Bill, thanks for sharing your video! Informational

Awesome Content. Not a lot of this stuff being shown. Nice to see someone else dealing with these set ups.

Thank you for sharing this chiller video

Any time you get an evap freeze code on a McQuay chiller you need to check your refrigerant levels and make sure your exv ain't sticking. That is very common on those chillers. If it was not getting enough water flow the flow switch should shut it down before the evap would freeze.

No water feed is a common thing, as you don`t want to add straight water to the glycol as it will dilute the mixture and make the freeze point higher. If you need to add ,it should be mixed together and the freeze point checked and verified before pumping it into the system. You can get pre mix for this. Normally a 50 -50 mix will give you -30 degrees f. You are at -23 degrees f ,if you could calculate the amount of your system in gallons ,you could determine how much glycol to add to the system based on what the freeze point temperature is specified. If you can find the o&m manuals for that place you could look up what the engineer specified the freeze point to be. Also why drain the system in the winter? I thought the reason for the glycol is so you don`t have to drain as long as the freeze point of the mix is low enough. Also check the delta t across that heat exchanger with thermometers on entering and leaving, that would be a good start to see if the thing is getting flow or not. If it`s getting below the chillers lowest set temperature in the control it could be the exchanger is fouled or possible strainer .Check the sensors for the correct readings for the given temperature with a meter.

Do keep us posted on future videos like these Your learning process helps me a Great too.God Bless

There’s nothing like getting a new piece of equipment and a new job position to keep you out of boredom and your mind sharp. Brings me back to my HVAC/R commercial refrigeration School days and Laney College HVAC program and building automation that’s the only place I’ve had this kind of exposure to this kind of equipment. Always wanted to play with those big toys.

Glad to see multiple videos...I thought you were giving up on content. Glad to have you doing new ones

I’d be checking for flow, EFT/LFT temp probes. Also I’ve found myself chasing my tail a few times in the past from air pockets in systems, especially if you’ve got swing gate non return valves in the system… cool chiller though 👍🏻

From 8 years of experience in BAS installation, maintenance and operation, here are few quick start tips: -Start fresh. Don't trust existing graphical schematics or labelling on equipment. Follow each network (chilled water, heating water, individual air handlers, etc) and draw them out. You need exact postion of fittings and equipement in relation to one another in order to troubleshoot. -Find as much documentation as you can on the installed equipment. That means pump curves, chiller performance and limitations, etc. This can help answer many questions over time as to the designed intent of the systems' operation. -Find BAS documentation and system design documentation. The Honeywell Gray Manual is a good reference. Why BAS? It is the maestro of the HVAC orchestra installed in each specific building.

I started on little house hold hvac stuff and hated working in people’s houses especially the rotten pigs that made me puke. Went on to work commercial and industrial and loved boilers. The bigger the better and in the end of that career I just worked in the boiler plants. Three stories of nothing but boiler, hot pipes and controls. My advice is grab the knowledge of someone that may have worked the equipment learn what is there and operation once you know it then there is always changes to better the operation such as upgrades. I did lots before our jobs went by the wayside. All those plants I worked at were built in the 40’s thru the 60’s and upgraded from coal fired to dual fuel and latest and greatest controls and then torn down in 2005. Sure do miss that type of work.

I got out of commercial refrigeration and air conditioning in 2015. Started doing conveyors for distribution center for 3 years. Then transferred to industrial ammonia refrigeration for about last 3 years. I am hoping to get into chillers since I don't have much experience in that area of HVAC.

That plug on the flange on the side of the pump is to take a pressure reading on the suction side but after the strainer. That way you can know what your drop is across it. After you drain, I would tie that port into your existing gauge with another ball valve.

Good one Bill👍

Citric acid is what I've seen the water treatment guys use around here for plugged water coils, worked well.

Nice! The perfect valve is called a haufman valve. I believe the oily feeling is a glycol mix. Everything is hand assembled on large systems so depending on who built it, it’s going to be a learning curve. Lol good times!

Most people Don’t wanna chance of having glycol flow back in To the domestic water. Need to add a backflow preventer and still valve it off when not in use because of Raising the freezing point by adding water without glycol as in a water leak.

Thanks for sharing, I

The discharge on the pump could/ should have a check or butterfly valve call it what you will if there's multiple pumps, might be partially blocked/ stuck or flapping around, with the glycol you can use a beer hydrometer like a glass tube.

Thanks a lot sir

I'm just a domestic plumber in the UK. When I have seen a gauge jumping like that it's when there is a blockage or valve closed. That 'strainer' could be clogged and can't pump through it properly and that's why pressure has risen and jumping on supply and your pressure so low on return... I could be wrong but just throwing my thoughts out there.

Where I worked they moved the water to a didn`t location have to be next to the expansion tanks. I would have shut the main pump off to check pressures . That was quite a drop threw that strainer or restriction farther down the line. Would check flow rate with pump off maybe at the air bleeder had a shutoff there .

One gets spoiled. Industrial systems are by far and away my favorite, but all troubleshooting scenarios are somewhat satisfying. I've worked on a lot of Air handling systems that are the size of a house. The easiest economizing units are the ones that have both intake and exhaust dampers / controls. The ones that are the biggest pain are the ones that have only intake air economizers and then you have various exhaust fans in the building to balance differential pressure between inside and outside the building. I've gotten involved in having to write some complex software in order to stage up exhaust dampers and fans to meet the levels of intake economizer damper positions (used for Supply Air temperature control).. The internal structure of the walls made it impossible to try and use differential pressure sensors for control, there would have had to have been dozens of them installed costing a fortune. In the best of circumstances it's difficult to tune the PID loops that are necessary to get those working right. I had to use trial and error ratios basically trying to tune by guesses at air volumes and then spot checking the building pressure. Having both intake and exhaust on the units is far simpler. Thanks for sharing..

Yes l was just like you light commercial refrigeration & HVAC service truck got off the road 2003 about 8 years ago l got job as plant operator was here from being of the construction of the building of starting the equipment with contractor .

You need to check the pump drive to see minimum pump setting. Could be a plugged strainer or flow issues. Balance flow at chiller evaporator ...typically 2.5 gpm/ ton

Need a refractometer to correctly check the glycol. To make sure it is staying at the percentage you want in the system also need to check nitrite levels in the system if they are 300-600 nitrite for a cooling loop there should be no corrosion going on in the system. A heating loop you want higher 600-900 nitrite. Those are the levels for the chemicals treatment I use in chill and hot water loop. I do both Commercial HVAC and Water treatment it's a good knowledge to have.

The ball valve on that line going to the discharge pressure gauge, it can be closed down ( but still open) to take away the fluttering needle.

Welcome to chiller tech side of things lol

I always hated the MicroTech 2 controllers. They are a pain to navigate, but you can look and see varying temps and pressures inside the evap. MicroTech 1 and 3 arent too bad, 1 being the easiest (imo) to navigate. This can help you figure out what path possible you can go down on your troubleshooting.

If the setpoint is in the 50s you should definitely check the temperature probes to see if the are accurate.

Cool man

For the pump flopping around with the gauge you could try venting it. Not sure it will work though

If I could give you any advice, if you are truly needing to check pressures in multiple spots, carry around a small bag with multiple adapters, and attempt to use the same gauge for every reading if possible

That electric conversion from pneumatics is called DDC.

Adding city water to closed loop..? Chilled water? Or glycol? Any chemical treatment..? Loop bleed?

Very nice Bill.. Impressive.! Bryan Tyler services

What was the beautiful tree with red flowers in back door of the mechanical room?????

instead of al the calculations, read the permanent marker scribbles on the pipe insulation? which is likely the proper average pressures. lol you need more pressure gauges, I'm assuming the total pump pressure varies with demand load. cooler weather less circuits open at once, lower volume flow = increased pressure du to excessive fluid pumped.

Freezing alarm could also be a faulty temperarture sensor, intermittent or permanent on the chilled glycol side. Check if the temperature on the chiller display matches reality with a termometer.

Im thinking about getting a job that requires maintaining chillers. Would you recommend hopping straight into them since im just an apprentice? Im no expert however i did apply myself while in school and caught on quickly. Would a couple of years in residential even do me any good?

How do you differentiate between something that would called an hvac unit and an air handeler? What type of refrigerant is used in an air handeler? Is it like a giant glycol system?

I used to see that error code it was the temp sensor in the inlet to evaporator.

That time of 0024 is 24 minutes after midnight, if the clock is correct. Since you got a low temp alarm, having it happen at night would make some sense. If you are used to seeing 30 PSI on the outflow of that pump, and you are now seeing 40 PSI, it seems to me this indicates some sort of partial obstruction (or at least a change) in the flow path. Since the input side of the pump is running the expected 10 PSI, the flow can't be completely blocked, or you might expect to see a pressure drop (from the expected) on the input side. A higher than expected pump output pressure with an expected pump input pressure suggests a flow obstruction, and therefore a reduced flow volume, and for a constant pipe size, a reduced flow velocity. If the temperature sensor is on the output of the chiller coils, and the flow is slower than expected, the coolant may be spending more time than expected in the chiller coils. If the OAT is quite cool, this could result in a greater than expected temperature loss in the coolant going thru the chiller. This might result in triggering a low temp alarm on the exit of the chiller. Now I'm not an HVAC guy, but I think from the symptoms I'd be inclined to investigate the higher than expected pump output pressure. Maybe there is a valve that is not opening completely, or something else simple. If you have any history on chiller output temperature or temp drop across the chiller that might also be interesting, but I think that a larger than expected temp drop would still point back to a flow restriction.

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But your pressure at the Heat Exchanger was lower when the system was down. Did you check the pressure at the HE when the system came on? I think checking that strainer is good. It might be clogged. What are the pressures and temperatures in the Refrigeration cycle? Thank you for this video. Digging into chillers a lot lately as well.

Water lines are not needed on the feed tanks since you have glycol in the system it prevents people from diluting the glycol any more & also prevents glycol to back feed into your drinking water , With glycol at that high of a mix will not freeze unless out side air is -10 and even that it will just slush up, Heat transfer is better with ethylene glycol than with propylene glycol, propylene glycol is more eco friendly. Listing to the pumps sounds like you got air in the system, check your high points for air bleeders that might not be working

there shouldn't be oil in the system ??

Did you check the flux capacitor 🙃

Sounds like a flow issue. Moving too slowly thru the chiller. Along with a pretty big pump differential. Could be a clogged strainer or even a control issue at the VAVs. Water isn’t making it back to the pumps. Also I think you said the expansion tank wasn’t open, that’s an important part of your system. But not the cause of your situation.

Hello sir, I have one here with me here when we start the compressors it runs for 2 second and stop and the system didn't receive gas after the pressure there is high pressure in the condensing part and less pressure in the everprator, sir what is the solution.

I work in BAS/HVACR for 15 year both install and programming if you have any questions feel free to reach out and ask

Anyone know a course I can take for learning the bigger stuff

Electronically powered bilemo valves

When in doubt pull some strainers out 👍

Common return air shaft

Check your sensors.

With glycol in there, why winterize?

“Getting your shit kicked in today “

Bill I’m confused? If your bringing 100% outside air so much so that you are purging the return out of the building? Why is the system looking to cool? The cooling lock out should lock out the chillers. Is it possible that the chiller is trying to provide chill water while the system is in full economize causing the water temps to go to low when the outside air gets colder? It just sterile me odd that your running the chiller when it’s in full economize mode? 😳

I'd guess air in the system.

This is sarcastically funny. SUBCRIBE

00:28 is 12:28AM not afternoon

Not the biggest picture diagnosis I've seen

Why do i heave a unrealistic fear of opening a door and its pitch black and imaging an deep hole to fall into 🤷

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