[SOLVED] NZXT Sentry 3 Problem

dpriest

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I just installed the Sentry 3 to power Noctua NF-A14 iPPC-3000 PWM, 4-Pin fans. I only want to use manual mode because these fans are super loud. When I am not encoding video, I am setting the fans at 40%. I am using the CORSAIR TX750M, 750 Watt, 80+ Gold Certified power supply. The problem right from the beginning is that the fans intermittently speed up to full throttle and then slow back down, where I cannot keep the fans running at a constant low speed except when I run at 100%. I had the Sentry Mix 2 before this controller and never had these issues. Please help.

Here are the specs of the fan:

Frame Technology: AAO

Max. Input Power: 6,6 W

Max. Input Current: 0,55 A

Voltage: 12 V

MTBF: > 150.000 h

Scope of Delivery: Fan
 
Solution
With 5W per channel, Senty 3 can't fully power the 6.6W Noctua fans. That can be the sole reason why you have issues with Sentry 3.

I too like analog fan controller more than digital. Hence why i have Tt Commander F6 RGB in my main build. Sentry 3 is in my wife's PC since she likes the digital control more.

For something else than Sentry Mix 2, you can also look towards Tt Commander F6 RGB,
specs: https://www.thermaltake.com/products-model.aspx?id=C_00002777
pcpp: https://pcpartpicker.com/product/9w3H99/thermaltake-commander-f6-rgb-fan-controller-ac-024-bn1nan-a1
video tutorial:
View: https://www.youtube.com/watch?v=8_S-CbNXoxo


While Tt Commander F6 RGB has digital display, it still...

Aeacus

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The auto 100% power, on start-up is built-in to the Sentry 3 and can't be disabled. (I have the Sentry 3 in my Haswell build as well, full specs with pics in my sig.)

Reason why fan controller gives fans 100% voltage on start-up is because some fans won't start spinning until they get the full 12V for few seconds. Look it as a built-in safeguard.

Many fan controllers have this feature built-in. My Sentry 3, Aerocool X-Vision (AMD build) and Thermaltake Commander F6 RGB (Skylake build) all have that feature while only my Thermaltake Commander F6 RGB has this feature toggle-able. Though, to make sure my fans are operational, i've enabled this feature in my Thermaltake Commander F6 RGB as well.

As far as running fans in the lowest 40% setting goes, my Sentry 3 works without issues. I have NZXT AER140 RGB and Corsair ML140 Pro blue LED fans connected to it. On start-up, all 5x fans go 100% for few seconds. After that, they all slow down to the specified speeds i've set them (ch#1 - 40%; ch#2 - 40%; ch#3 - 0%; ch#4 - 40%; ch#5 - 40%). Oh, i don't have the Link feature enabled and i've selected the manual (middle) mode.
 

dpriest

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I'm aware of the 100% start up speed. Again, the issue is that while my PC is running, the fans speed up from 40% (quiet) to 100% and then cycle back down. I have an AMD build with the Threadripper 1950x overclocked to 3.9Ghz. I am cooling it with the Thermalright Silver Arrow TR4 heatsink and have 7 of the Noctua NF-A14 industrial fans.

My fan controller needs are very simple. When I am not encoding video, I want to keep the fans turned down so they are quiet. When I am encoding video, I run the fans at 100% and walk away from my computer, letting it do its thing. Sometimes I have several videos in the queue so my PC will be running for several hours or even a day encoding. This system is very loud with all fans at 100%. I sounds like a jet turbine engine.
 

Aeacus

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What's your temperature target in Sentry 3? Since that's one of the two features which forces the fans to run 100%. When temp target is reached, regardless the mode you're in, all fans get full 12V until the temp drops below set limit.
Either increase the temp target or relocate the temp sensor.

Also, the issue could be with the Noctua fans. It is possible that your Noctua fans can't operate at 40% (4.8V) and they stop at that level. If they do, Sentry 3 will detect fan failure and gives fan full 12V in attempt to restart it. Hence the 40% -> 100% -> 40% fluctuation.
Set the level to 50% or 60% and look if the fan speed fluctuates between 100% and set level as well.

I made a bit testing with my fans and my Tt Commander F6 RGB fan controller, since it has voltage control of 0.1V steps, from 0.0V to 12.0V (ideal for testing);
2.8V - Corsair ML140 Pro fan stops and fan failure alarm sounds.
3.5V - Corsair ML140 Pro fan spins at about 700 RPM.
4.5V - NZXT AER140 RGB fan stops and fan failure alarm sounds (ML140 Pro spins at about 800 RPM).
6.0V - NZXT AER140 RGB fan spins at about 1100 RPM (ML140 Pro spins at about 1100 RPM).

To put it short, different fans have different cut off point when it comes to the DC (voltage) control.
 

dpriest

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Temperature target? I don't know how to adjust the temperature target. Is it possible? To be honest, I don't want this temperature probe. The probe now is not even on the motherboard but in the 5.25" bay. I monitor the temperature of my cpu, motherboard and memory by software (HWMonitor).

My noctua fans do spin at 40% and do not stop. 50-60% is on the loud side with these fans. As I mentioned previously, I had the NZXT Sentry Mix 2 before this and this problem never happened.
 

Aeacus

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After fiddling with my Sentry 3 and researching some more about it, it seems that temp target can't be changed. Also, Manual profile seems to be unaffected with the temp target, where only Quiet and Performance modes are affected with following steps:

Temp - Quiet - Performance
80C - 100% - 100%
75C - 90% - 100%
70C - 80% - 100%
65C - 70% - 100%
60C - 60% - 100%
55C - 60% - 90%
50C - 50% - 80%
45C - 45% - 70%
40C - 40% - 60%
35C - 40% - 50%
30C - 40% - 40%
25C - 40% - 40%
20C - 40% - 40%

Sentry Mix 2 has minimum power to fans at 40%. Here, it could be possible that Sentry 3 40% power is lower than it is for Sentry Mix 2. Since i don't have a watt-meter, i can't measure how much voltage Sentry 3 feeds at 40% level.

Also, i'm a bit confused here. You say that your fans spin at 40% but fans go to 100% at random? Do all 5x fans do that at the same time? Also, which profile you're using?
And while 50% or 60% can be noisy, have you actually tested when running at 50%/60% to see if the fan speed goes to 100% as well?
 

dpriest

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After fiddling with my Sentry 3 and researching some more about it, it seems that temp target can't be changed. Also, Manual profile seems to be unaffected with the temp target, where only Quiet and Performance modes are affected with following steps:

Temp - Quiet - Performance
80C - 100% - 100%
75C - 90% - 100%
70C - 80% - 100%
65C - 70% - 100%
60C - 60% - 100%
55C - 60% - 90%
50C - 50% - 80%
45C - 45% - 70%
40C - 40% - 60%
35C - 40% - 50%
30C - 40% - 40%
25C - 40% - 40%
20C - 40% - 40%

Sentry Mix 2 has minimum power to fans at 40%. Here, it could be possible that Sentry 3 40% power is lower than it is for Sentry Mix 2. Since i don't have a watt-meter, i can't measure how much voltage Sentry 3 feeds at 40% level.

Also, i'm a bit confused here. You say that your fans spin at 40% but fans go to 100% at random? Do all 5x fans do that at the same time? Also, which profile you're using?
And while 50% or 60% can be noisy, have you actually tested when running at 50%/60% to see if the fan speed goes to 100% as well?
 

dpriest

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I have been in touch with NZXT support. They say the maximum watts per channel is 5 to draw on even though the specs say 15 watts per channel. I did not have these issues as severe with the sentry mix 2. I ordered a new one of these on NewEgg. The Sentry Mix 2 has 30 watt per channel which is twice that of the Sentry 3. With the Sentry Mix 2, I did notice slight fluctuations in fan speed and nothing at all like the Sentry 3. The digital display, temperature probe and different modes are all gimmicks I don't need.

I'm going to try to return this one and go with the fully analog, no frills old style that worked well for several years.
 

Aeacus

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With 5W per channel, Senty 3 can't fully power the 6.6W Noctua fans. That can be the sole reason why you have issues with Sentry 3.

I too like analog fan controller more than digital. Hence why i have Tt Commander F6 RGB in my main build. Sentry 3 is in my wife's PC since she likes the digital control more.

For something else than Sentry Mix 2, you can also look towards Tt Commander F6 RGB,
specs: https://www.thermaltake.com/products-model.aspx?id=C_00002777
pcpp: https://pcpartpicker.com/product/9w3H99/thermaltake-commander-f6-rgb-fan-controller-ac-024-bn1nan-a1
video tutorial:
View: https://www.youtube.com/watch?v=8_S-CbNXoxo


While Tt Commander F6 RGB has digital display, it still has analog control. It also has 6x channels and 30W per channel. Also, while you can't stop fans with Senty Mix 2 since it's minimum setting is 40%, you can stop fans with F6 RGB. Like i said above, the 100% fan power on start-up is toggle-able and it's one of the few fan controllers out there that enables to control your fans with 0.1V steps, from 0.0V to 12.0V. F6 RGB also has 6x temp sensors (one per channel) which you don't need to use if you don't like them. Oh, ch#5 and ch#6 also support Tt Lumi RGB LED strips if you're into that.
 
Solution

dpriest

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Thanks for the tip. I ordered the Tt Commander F6 and it should be here tomorrow. I thought the NZXT Sentry Mix 2 is still available but I can't find it anywhere. The Commander has the same specs as the Sentry Mix 2 with 30 watts per channel so I'm sure it will work fine. I'm surprised the Sentry 3 cannot handle these Noctua industrial fans because it is usually enthusiasts that have the need for fan controllers and for overclocked systems there are a lot of users that are using these fans because with the exception of noise when running 100%, the are arguably the best fans on the market for cooling
 

Aeacus

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The thing with 5.25" external bay fan controllers is that you need to have 5.25" external bay where to put it. Most users nowadays pick a PC case that has no 5.25" bays where to put it. Due to that, 5.25" external bay fan controllers are slowly fading away where only PC enthusiasts use them nowadays.

While it's true that Noctua industrial fans are good when it comes to the cooling, they are not the best fans on the market. Noctua fans are considered the best consumer grade fans but there are also industrial grade fans. If you want the absolute best, look towards Delta industrial fans.