Hello!
My controller has been making a whining noise when it's running during peak hours. (Someone told me it probably is the cooling fans) I just want to make sure that this is normal.
I have (4) 250 watt panels wired together as a set and another (4) 265 watt panels wirered together for another set. It all goes through a connector box then to the controller. Our battery bank consists of 20 6v wired for a 24 volt system. When charging, the voltage coming in from the panels is 110-111 volts. The unit is just over 3 years old and this noise has been going on for a while. I also have a Conext 4024 inverter/charger
* I have never done any firmware updates nor know how to do them. I have a Mac Pro laptop
Any ideals or suggestions?
Thank you
Jim
The noise is only when under Full sun and in the Mid day?
Is it a constant whine or WHRRRRRR? does it come on and then Off?
What are the ambient temps in the Power room?
What are the temps shown in the MNGP window?... if they are significantly over 45* - 50*C It is normal... The are doing their job...
However some of the early model numbers do have noisy fans...
There has been a fan replacement kit posted recently too... you might have to initiate a repair ticket, found on the main MidNite web page.
I just reread your post and see that you are inputting ~110V and stepping it down to 24V.... the norm would be to step down from ~70 -75 V (nominal 48V ) to ~35V (nominal 24V) to minimize heat production and maximize conversion. a 48V configuration would be more efficient without changing any of the panel wiring.
I think I remember reading that some of the earlier Classic fans needed a little shim in to keep them from rattling around in the frame too much and that was cause of excessive noise. There were discussions on the forum how to do it and it wasn't that difficult .
Larry
When the Classic if first powered up, it does a fan self-check by turning them on for just a couple of seconds.
You might try powering it off and back on again and see if you hear that noise at this time.
No power will be passing through when it first powers up either. It takes a few more seconds to start charging.
boB
Quote from: JimNAZ on September 17, 2017, 07:47:20 PM
My controller has been making a whining noise when it's running during peak hours. (Someone told me it probably is the cooling fans) I just want to make sure that this is normal.
...
Any ideals or suggestions?
Contact Midnite support.
My Classic 200 was whining pretty badly under similar conditions (a quick audio analysis indicated peaks at 11.5kHz and 14kHz) - definitely not the fans, and since it's inside my office, it was pretty well annoying. It seemed to be correlated to high charging voltages and high charging amps (so sunny winter mornings as it got up towards absorb were really loud). For mine, it was temperature sensitive - changing the unit temperature impacted the whining, but it eventually got bad enough that I contacted support. We tried a few different things, including firmware updates, and nothing worked, so I sent it back for repairs. A week and a half later, I've got it back and it's not whining so far! I'll give it a while to settle in, but it sounds like it's a somewhat known issue that can be resolved by replacing a few components on the board.
To update your firmware with a Macbook Pro, you could do something with a virtual machine, or just borrow a techie friend with a Windows laptop. :)
The high frequency noise is more than likely coming from the inductors... Those are the closest components to a speaker in the
Classic other than the speaker itself, in the MNGP remote.
Maybe something was done to the Classic when it came back. Or maybe just the moving around in shipping and handling
was enough to quiet it down ?
If it happens again, try squeezing and moving the Classic body around while it is whining away and see if it changes anything.
boB
Quote from: boB on May 26, 2018, 04:18:00 AM
Maybe something was done to the Classic when it came back. Or maybe just the moving around in shipping and handling
was enough to quiet it down ?
The tech confirmed that they replaced the inductors - they were able to reproduce the issue, though there were no functional problems with them. Apparently some inductors are just louder than others.
Quote from: Syonyk on May 26, 2018, 06:42:47 PM
Quote from: boB on May 26, 2018, 04:18:00 AM
Maybe something was done to the Classic when it came back. Or maybe just the moving around in shipping and handling
was enough to quiet it down ?
The tech confirmed that they replaced the inductors - they were able to reproduce the issue, though there were no functional problems with them. Apparently some inductors are just louder than others.
OK, great ! Yeah, maybe it was wound looser than the other inductors and/or the varnishing wasn't quite good enough to hold
the windings down.
boB
I'd expect a varnishing issue, because it only started whining after a year and a half of operation, and got progressively worse. It hasn't done it since day one, or I'd have been really annoyed.
In any case, I'm quite happy that they were able to repair the unit and that it's quiet now!
I've added an external "sucker fan" to the vents (just built something with a low power 120mm computer fan and some cardboard/tape) to help cool it without requiring the internal fans to kick on as well. They're quite disruptive to a quiet workspace on a quiet morning.