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Head pressure is pretty high. What type of condenser and what’s the ambient temp? What’s head pressure normally run on this system? Is it a DX or pumped liquid recirc?
could be any number of things. compressor capacity, low refrigerant charge, oil logged evap., brine system problem. if the sensor is actually good and is always reading around 29ppm, you may have a leak.
The sensor was just tested though, at least the paperwork indicates that
These are great questions that I can try to find out. I have an amp meter, but Im not allowed to open any part of the machine to measure the draw. The machine is a piston compressor. Oil levels are checked every 2 hours, and oil is added when needed. Im not sure how often oil is added to the compressors.
Originally Posted by Poodle Head Mikey Is this a piston compressor or a screw compressor? A 1º difference across the chiller's evaporator is very low - especially with a warm floor. <g> The machine isn't Doing anything - Is the compressor loaded? Is the amp draw 50% of FLA or higher? Was the brine flow 'adjusted correctly' previously and now is wide open / 100% of the pump capacity? 24 lb. suction is about -10-12º F. If the leaving brine is +19º F. that is a 30º chiller approach temp. - which blows. <g> The leaving water should be closer to 0º, and preferably a little lower, with that suction pressure. Has the machine ever faulted on low oil pressure? Has anyone been adding oil to the machine? PHM ---------- These are great questions that I can try to find out. I have an amp meter, but Im not allowed to open any part of the machine to measure the draw. The machine is a piston compressor. Oil levels are checked every 2 hours, and oil is added when needed. Im not sure how often oil is added to the compressors.
Or the sensor has not been tested and inspected, and is bad.
most alarm systems are set to 25ppm osha is 50ppm for 8 hours. if their is a purge in the same room and it's not performing correctly it will put ammonia in the air. could also be a shaft seal leak if a bearing is noisy. you need a serviceman to check the system and some education because i know this is overwhelming.
Is this a piston compressor or a screw compressor? A 1º difference across the chiller's evaporator is very low - especially with a warm floor. <g> The machine isn't Doing anything - Is the compressor loaded? Is the amp draw 50% of FLA or higher? Was the brine flow 'adjusted correctly' previously and now is wide open / 100% of the pump capacity? 24 lb. suction is about -10-12º F. If the leaving brine is +19º F. that is a 30º chiller approach temp. - which blows. <g> The leaving water should be closer to 0º, and preferably a little lower, with that suction pressure. Has the machine ever faulted on low oil pressure? Has anyone been adding oil to the machine? PHM ---------- Originally Posted by chill1986 Hey, Hopefully I can articulate myself properly for you guys to answer my question. I am a residential air conditioning technician who got into the arena side of things as an operator. I do not work on the systems, I mainly work with technicians that come. I just got into work today, and i found out that our rink is hardly freezing. Our brine loop is giving us 20 degrees coming in, and 19 going out. Our head pressure is reaching 190 degrees and our suction is 24. My supervisor was advised to try and open the hand expansion valve to allow more liquid ammonia into the chiller, but I fail to see why flooding the chiller would take more heat out of the system (the pressures changed to 160 and 30 suction). The supervisor found the problem persisted and re-closed the valve and the drum valve opened up again. We have two controllers monitoring the rink. One is an infrared system that aims at the top of the slab and the other is monitoring the brine return and turning the compressors on when needed. When we ran the system only on the brine return temperature, we found the ice to be better but the brine pump is always running. Currently the infrared temperature controller is monitoring the slab temperature. I dont have the wet bulb or dry, but I will get them shortly. As of right now we dont have a machine that monitors these percentages. I own a UEI one, but I dont completely trust it. This is a hard question, but any insight will help.
The Brine system has not been tested yet. Its hard to know exactly what has been tested, because my supervisor is the one in charge of monitoring these things. That being said, sometimes I feel like he has stopped caring about the plant. the other day he called Cimco and told them the symptoms; the Cimco guy over the phone tries to diagnose it and tells him to open the hand expansion valve to allow more liquid into the chiller. But why is he ok with a phone diagnoses on an ammonia system? its troubling the more I think about it.
One of our compressor motors is squealing pretty bad, so theres a possible bearing issue with the unit. Can a bearing issue cause a drop in the pull of the compressor enough to lower performance? I would check the amp draw on the unit, however Im not technically insured to work on any component, and all work is done by outside agents.
Well, probably the most disconcerting issue is the fact the ammonia sensor before walking into the actual compressor room reads 29 PPM on average. I dont know how typical that is for most plants that you guys have worked on. No one ever says anything, and Cimco has been in there half a hundred times while the sensor has read 29 PPM. Not to mention, sometimes the sensor reads out "fau". As for the smell, I dont smell anything unusual in the room.
I here or read a lot of Guessing going on................ That's just a Little Concerning!!!
The system should be logged at least twice a day everyday.Pressures, temps, amps, pump pressures and purge unit. Then you can see what is going on and maybe head off a problem. Without having more info it's hard to help. Don't trust a gage or a thermometer without checking it out first.
Has the brine system been checked out? I was ask to trouble shoot a system similar to this in a dairy and the brine system was low on brine.
The good thing about ammonia is that if there is a leak, even a tiny one, you will smell it. If no one has smelled ammonia, then you most likely aren't low on refrigerant. I'm not sure what your problem is, but I thought I'd put that up there. Keep us posted if you figure out what the problem is.
When the system is running, the bottom sight glass is full and the upper sight glass is empty. Other than pulling it out and weighing it; I would believe there is enough. When the system is off, the glasses are both almost all full.
Do you have enough refrigerant in the system?
Arena Ammonia System Hey, Hopefully I can articulate myself properly for you guys to answer my question. I am a residential air conditioning technician who got into the arena side of things as an operator. I do not work on the systems, I mainly work with technicians that come. I just got into work today, and i found out that our rink is hardly freezing. Our brine loop is giving us 20 degrees coming in, and 19 going out. Our head pressure is reaching 190 degrees and our suction is 24. My supervisor was advised to try and open the hand expansion valve to allow more liquid ammonia into the chiller, but I fail to see why flooding the chiller would take more heat out of the system (the pressures changed to 160 and 30 suction). The supervisor found the problem persisted and re-closed the valve and the drum valve opened up again. We have two controllers monitoring the rink. One is an infrared system that aims at the top of the slab and the other is monitoring the brine return and turning the compressors on when needed. When we ran the system only on the brine return temperature, we found the ice to be better but the brine pump is always running. Currently the infrared temperature controller is monitoring the slab temperature. I dont have the wet bulb or dry, but I will get them shortly. As of right now we dont have a machine that monitors these percentages. I own a UEI one, but I dont completely trust it. This is a hard question, but any insight will help.
Arena Ammonia System
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