Brownouts from our chiller
- Thread starterStradivariusBone
- Start date
It's common for additions to the buildings or new buildings added on campus to get tagged onto the CHW loop so the upgrade may have added more capacity. If this is a county facility, there's actually a greater chance of this because they might be selling excess CHW to other properties nearby or leveraging this system to support other county facilities down the road. We also see a number of groups here in FL who do ice storage. They run the chiller system all night to make ice at off-peak hours, and then during peak hours turn the chillers off or run at a reduced load and just circulate water over the stored ice until mid/late afternoon. That way most of their HVAC loads are running while they get discounted rates from the utility.
Really hard to guess what the circumstances and former/new conditions are without looking at drawings though.
That's an interesting observation, Mike. The original building was constructed in 1995, complete with it's own chiller plant. The main school campus is handled by two chiller units with several ice storage units. I'm guessing the thought was since the auditorium usage would center around non-peak hours for the main chiller plant, it would make sense to have it on its own system since the main chiller switches over to make ice for the night around 8 or 9pm.
In or around 2007, they made an addition of a band room and ancillary offices and practice rooms to the back of the auditorium, but also added that facility to the chilled water loop of the auditorium plant. This was still the aging chiller from 1995. As far as I know, the band room addition is fed by the same exterior transformer and is not shared on our main distribution panel in the auditorium. At least there's no disconnect labeled band room in our mech rooms anyway. The interesting thing is the lights dim over there as well when the chiller compressor starts.
So maybe 2016 or 2017 we finally made the cut to replace the old chiller with the upgraded one. No ice plant, but just a regular chilled water on demand setup, still feeding the band room. It is then theoretically possible that they went with a chiller with greater capacity, knowing that the original one might not have had that built in since the addition was not done until almost a decade after the original construction? That's speculation. Going from what you all have been saying about the feeder, I'm given to wonder if this is not an issue in the underground conduit? We have had a number of water intrusion issues over the years as well as lightning damage frying data lines in the underground runs. A faulty conductor under the slab seems like a potential issue here. In any event, this is all good food for thought. I'm going to submit another work order on Monday and get in touch with my county electrician friend. I'm hoping he's looking for rabbits to chase as well right now. I'll keep the thread updated as I find out more!
In or around 2007, they made an addition of a band room and ancillary offices and practice rooms to the back of the auditorium, but also added that facility to the chilled water loop of the auditorium plant. This was still the aging chiller from 1995. As far as I know, the band room addition is fed by the same exterior transformer and is not shared on our main distribution panel in the auditorium. At least there's no disconnect labeled band room in our mech rooms anyway. The interesting thing is the lights dim over there as well when the chiller compressor starts.
So maybe 2016 or 2017 we finally made the cut to replace the old chiller with the upgraded one. No ice plant, but just a regular chilled water on demand setup, still feeding the band room. It is then theoretically possible that they went with a chiller with greater capacity, knowing that the original one might not have had that built in since the addition was not done until almost a decade after the original construction? That's speculation. Going from what you all have been saying about the feeder, I'm given to wonder if this is not an issue in the underground conduit? We have had a number of water intrusion issues over the years as well as lightning damage frying data lines in the underground runs. A faulty conductor under the slab seems like a potential issue here. In any event, this is all good food for thought. I'm going to submit another work order on Monday and get in touch with my county electrician friend. I'm hoping he's looking for rabbits to chase as well right now. I'll keep the thread updated as I find out more!
BillConnerFASTC
Well-Known Member
Oh yeah, good idea.
I'll mention the Electrical Engineer, lol. I'm at the mercy of people who don't like spending money of course and can't simply call 1-800-Engineer and press 4 for Electrical 
I think given the context that the power factor could be increasing energy costs and the damage that may be occurring to equipment, I might be able to make a decent case that further study is warranted.
I think given the context that the power factor could be increasing energy costs and the damage that may be occurring to equipment, I might be able to make a decent case that further study is warranted.
tjrobb
Well-Known Member
Yeah, water is possible. I have a story of a receptacle circuit that the phase wire was completely corroded through, continuity was only provided by the water in the conduit (which is how they had 97V).
Jay Ashworth
Well-Known Member
My snappy answer is that if you have a 460/480VAC internal distribution system, you should have a house sparky, even if he's not full time.
But yet, what everyone else said; sounds like your new chiller has a starting amp draw enough higher than the old one that it pulls the entire facility voltage below nominal. And that is likeliest to be the street drop, not internal, cause if it was just the wires *to the chiller*, it wouldn't affect the others as much. It would probably still dip them some, but...
What I'm wondering is why the power quality meter didn't show that. Did they give you a stripchart?
But yet, what everyone else said; sounds like your new chiller has a starting amp draw enough higher than the old one that it pulls the entire facility voltage below nominal. And that is likeliest to be the street drop, not internal, cause if it was just the wires *to the chiller*, it wouldn't affect the others as much. It would probably still dip them some, but...
What I'm wondering is why the power quality meter didn't show that. Did they give you a stripchart?
Dionysus
Well-Known Member
I THOUGHT I had replied to this... Here is a link to a power provider website talking about itt...
Power factor and your bill
I did some investigation and we're familiar with this project. We were the third-party Cx agent which basically means once the system is installed one of our mechanical engineers confirms it has been brought online and programmed correctly. I've reached out to the engineers in my Cocoa office who were involved in this project for more info.
Actually, the district kind of does have this in place. There is a master continuing services agreement for MEP Engineering services, which basically means there's an expedited process in place for procuring engineering services, particularly for these kinds of smaller projects. My firm as well as a couple others are part of that agreement. I don't know how far your maintenance staff have escalated this up the food chain but if you get approval from someone in your facilities dept there's actually very little red tape involved. Waiting to hear back from my team in Cocoa who they normally work with from the district that they could flag this issue to.
I'm at the mercy of people who don't like spending money of course and can't simply call 1-800-Engineer and press 4 for Electrical
Actually, the district kind of does have this in place. There is a master continuing services agreement for MEP Engineering services, which basically means there's an expedited process in place for procuring engineering services, particularly for these kinds of smaller projects. My firm as well as a couple others are part of that agreement. I don't know how far your maintenance staff have escalated this up the food chain but if you get approval from someone in your facilities dept there's actually very little red tape involved. Waiting to hear back from my team in Cocoa who they normally work with from the district that they could flag this issue to.
Thanks for that, Mike! I spoke with my people here this morning so we'll see what comes of it.
Jay Ashworth
Well-Known Member
Spammer reported.
So... update?
So... update?
Not much to update unfortunately. I contacted a few friends I have up at facility plant, but right now they're still just trying to finish the HVAC automation upgrades (which don't work great) among other things that were spurred by the flurry of legislation post-Parkland (e.g. lots of security cameras, gates, etc.). It's kind of a mess overall, brownouts are still happening, but it hasn't been as noticeable lately because we just haven't had as many events as we usually do.
If the LED display is in Europe though, how does that help us here in America?
If the LED display is in Europe though, how does that help us here in America?
It shouldn't be that hard to track down. Measure where voltage sags and where it doesn't. If the voltage does not sag at the transformer, and it does at the lugs of the main breaker, then there is either a loose connection, or an undersized feeder between the two points. If it's good at the main lugs, and bad on branch breakers, then look hard at the the main breaker itself and the busses.
It doesn't take fancy test equipment. Some moderately priced voltmeters have fast responding, min/max hold, and should be able to measure the problem. A favorite of mine is the Fluke 87V. I used one to find similar problems. Get the right test leads to get solid, safe connections for long periods of time.
An infrared thermometer or IR camera can also help. Voltage drop on a connection means resistance and resulting heat. Discoloration and damaged insulation are also signs of trouble.
It doesn't take fancy test equipment. Some moderately priced voltmeters have fast responding, min/max hold, and should be able to measure the problem. A favorite of mine is the Fluke 87V. I used one to find similar problems. Get the right test leads to get solid, safe connections for long periods of time.
An infrared thermometer or IR camera can also help. Voltage drop on a connection means resistance and resulting heat. Discoloration and damaged insulation are also signs of trouble.
Lyle Williams
Well-Known Member
Jay Ashworth
Well-Known Member
Fun side trip: I like to describe our campus theatre/building as having "nuclear-powered air conditioning", a phrase I stole, from, probably, The Hunt For Red October. A little research this week, it turns out the central chiller plant that cools the 9 buildings on this campus, plus a bunch of other commercial customers, is a *3400-ton* Trane plant.
That's a whole lot of ice...
JonCarter
Well-Known Member
I'm with Bill Connor's comment way back last year. Get an EE involved, do some current load calcs, monitor the hardware, watch the voltages and current draws at critical points in the system and put together an info package of what's happening when and where. That's the only way you'll know if the problem is yours or the POCO's.
