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  1. #14
    Join Date
    Feb 2019
    Location
    Northeast Ohio
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    Quote Originally Posted by york56 View Post
    http://cgproducts.johnsoncontrols.co...c=129&req=YVFA


    Here is the Book if you care to read it.
    Thanks SO much for posting this link, york56. Apparently it's not available to customers on the JCI site.

  2. #15
    Join Date
    Nov 2011
    Location
    East Side
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    So how do you like it? Is this the first winter?

  3. #16
    Join Date
    Jan 2009
    Location
    winnipeg
    Posts
    24
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    I am not familiar with this unit, does it have 2 coils? one for the glycol and the other for refrigeration? If so Trane has one and there are issues with it, I am hoping they resolved the issues but the trane is a great machine.

  4. #17
    Join Date
    Feb 2019
    Location
    Northeast Ohio
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    21
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    Quote Originally Posted by pumpdown View Post
    I am not familiar with this unit, does it have 2 coils? one for the glycol and the other for refrigeration? If so Trane has one and there are issues with it, I am hoping they resolved the issues but the trane is a great machine.
    I just started here two weeks ago, but I've heard nothing but bad things about these, and in fact, I'm already dealing with some of those issues. All of these "made in Mexico" York machines seem to need a Pez dispenser loaded with condenser fans nearby, as they eat them like candy. I had a much smaller air-cooled York machine at my last place and it was no different. I'm also hearing refrigerant leak issues from the crew I just joined.

    And yes, it has two coils, one for glycol and one for refrigerant. The glycol coil totally blocks access to the refrigerant coil, so cleaning the refrigerant coil is virtually impossible. I suppose you COULD move the glycol coils (they're connected by hoses) but lord, it would be a nightmare.

  5. #18
    Join Date
    Nov 2011
    Location
    East Side
    Posts
    7,178
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    Quote Originally Posted by OHDataCenterGuy View Post
    I just started here two weeks ago, but I've heard nothing but bad things about these, and in fact, I'm already dealing with some of those issues. All of these "made in Mexico" York machines seem to need a Pez dispenser loaded with condenser fans nearby, as they eat them like candy. I had a much smaller air-cooled York machine at my last place and it was no different. I'm also hearing refrigerant leak issues from the crew I just joined.

    And yes, it has two coils, one for glycol and one for refrigerant. The glycol coil totally blocks access to the refrigerant coil, so cleaning the refrigerant coil is virtually impossible. I suppose you COULD move the glycol coils (they're connected by hoses) but lord, it would be a nightmare.
    You’re the guy we had a long discussion about switching career paths I believe? Glad
    You took the leap!! How’s the switch?

  6. #19
    Join Date
    Feb 2019
    Location
    Northeast Ohio
    Posts
    21
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    Quote Originally Posted by 71CHOPS View Post
    You’re the guy we had a long discussion about switching career paths I believe? Glad
    You took the leap!! How’s the switch?
    Well, the amount of time it took me to respond should give you some indication...

    I'm pleased to see that I've got a pretty good crew here to work with. But the facility is a disaster, as expected. In addition to having 3 POS air-cooled screw Yorks as our primary cooling, there's a complete lack of procedures and documentation. All of which is why they hired me, so I guess I should look at it as job security...

    The past two weeks have been like drinking from a fire hose. When I see a problem, if there's enough time to implement a correction on the spot, I do so. If not, I add it to the list. The list is getting to be VERY long. I estimate it'll take me a year or more to get this place where it needs to be. I'm just hoping nothing catastrophic occurs before I can do that...

  7. #20
    Join Date
    Nov 2019
    Posts
    4
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    In the process of trying to commission one of these for a customer. Keeps tripping out on low suction pressure. Talked to a guy who quit the local york service company specifically because of these chillers. The hybrid cooling automatically redirects water in to the free cooling loop, reducing flow through the mechanical cooling loop. The suction pressure cutout set point can be lowered to 20psi with the free cooling loop enabled, but it still isn't low enough. The only way to keep it from tripping is is to disable the free cooling and install a software upgrade that allows the low pressure cutout to be set at 10 psi. Apparently the free cooling loop won't recognize as being used with glycol, so it won't allow you to lower the cutout to a point where plain water would freeze. Primary pump is set to constant flow and does not have a VFD, so this may be an design problem. Remains to be seen. Either way, not a good look for York so far.

  8. #21
    Join Date
    Nov 2011
    Location
    East Side
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    Sounds like a lack of primary flow. Has the system Flow rate been determined?

  9. #22
    Join Date
    Nov 2019
    Posts
    4
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    Certified by and independent TAB contractor at 350gpm. System design was 320. Cant remember exactly what the chiller was rated at, but something like 260 min and 550 max.

  10. #23
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
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    I'm not familiar with these, but are saying that there are times when flow is split, and going thru both the free cooling and the evaporator at the same time? If so, I would think the evaporator flow would need to be considered as "variable flow", and the chiller would need to be set up so that the minimum flow rate (260 gpm in this instance) thru the evaporator is not violated. With the "total" flow rate being 350 gpm, this does not allow much wiggle room for flow to be diverted to free cooling, IF they operate at the same time.

    I expected these to operate in one mode or the other.
    In honor of RichardL: "Ain't 'None' of us as smart as 'All' of us".

  11. #24
    Join Date
    Nov 2019
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    A little further down the rabbit hole. The water valve does not modulate. The free cooling loop passes through the barrel after the free cooling coils. So apparently "hybrid" means mechanical cooling modulates and supplements based on temp after free cooling. Seems to me it would be difficult to meter capacity to make sure there is enough load after free cooling to prevent tripping low discharge pressure switch and still maintain a LWT

  12. #25
    Join Date
    Aug 2009
    Location
    Prattville, Alabama
    Posts
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    Sounds as though the free cooling is simply reducing the load on the mechanical cooling. And that is going to happen during cool or cold weather, when a chiller can sometimes struggle with low head pressure and light load. I hope it has a good performing low ambient control package on it. I would be concerned with the ability to mechanically unload, and the ability to maintain sufficient head pressure at that low load and low ambient. I think it's likely that the problem lies in one of these two, or even in both. Could be something as simple as a sensor. Or could be a misapplication, lol. Such as operation outside of design.

    There are some highly experienced York guys who are members here. Maybe they will join in.

    In the meantime, I would be checking out head pressure control. Such as, how does it to control? To a predetermined setpoint? To a differential pressure? Verify all sensors. Verify what is being sensed (this is based on bad memories of some older Tranes using temperature sensors, and converting that to pressure. I mention this because it wouldn't be the first time to see a bad idea resurface somewhere else).

    Good luck. If I think of anything, I'll post it.
    In honor of RichardL: "Ain't 'None' of us as smart as 'All' of us".

  13. #26
    Join Date
    Nov 2019
    Posts
    4
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    I think that is exactly the problem. The only way to manipulate the heat removal in the free cooling loop would be to modulate the fans. That would ensure there is enough load on the mechanical cooling to meet miminimum compressor capacity and not trip on low discharge pressure. Except the EWT at the barrel is what tells the mechanical cooling how much work needs to be done. By the time the water gets there, the fans are done doing their job. Like having teeth in your butt, by the time it gets there, the work is already done. The fans would almost have to predict the EWT at the barrel, BEFORE the water enters the free cooling loop.

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