Classic 250 Whining Noise

Started by JimNAZ, September 17, 2017, 07:47:20 PM

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JimNAZ

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

Westbranch

#1
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.
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 FW V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come

ClassicCrazy

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
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB

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
K7IQ 🌛  He/She/Me

Syonyk

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. :)

boB

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
K7IQ 🌛  He/She/Me

Syonyk

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.

boB

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
K7IQ 🌛  He/She/Me

Syonyk

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.