Falcon Christmas

Other Controllers and Hardware => General Hardware => Topic started by: vipersinu2 on January 06, 2018, 08:23:28 PM

Title: EBay power supplies boom!
Post by: vipersinu2 on January 06, 2018, 08:23:28 PM
Last year I just started getting into led lights. I bought 6 of these eBay 12v 60a powers supplies.
This month 3 blew out. The weird thing the fuse inside never blew.
I am only going to buy meanwell power supplies from  now on. Dave gave me a tip to check out arrow.com for power supplies
Title: Re: EBay power supplies boom!
Post by: AAH on January 08, 2018, 10:09:39 PM
It's a bit hard to tell from the photo but that looks like it's probably a MOV (metal oxide varistor) and is in the circuit need the input to protect the rest of the circuitry from over voltage spikes. Either you've copped some big power spikes or it's a 110V only power supply and it's connected to 240V. Meanwell supplies will likely have almost the exact same component in the exact same place. The quality may vary but it's literally a couple cent component regardless of the manufacturer.
Title: Re: EBay power supplies boom!
Post by: David_AVD on January 09, 2018, 04:41:49 AM
Could be a MOV or maybe an NTC (inrush limiter) if it was the latter, they can fail if the mains power is cycled off and on too quickly a few times in a row.
Title: Re: EBay power supplies boom!
Post by: AAH on January 09, 2018, 02:09:35 PM
Yep. David is probably right about it being a NTC (negative temperature coefficient resistor). Only closer inspection there looks like there's 2 of them with 1 each on the L and N mains inputs. They've both seen some damage and the "L" one has self destructed.
Title: Re: EBay power supplies boom!
Post by: vipersinu2 on January 09, 2018, 04:00:17 PM
Here is a 2nd power supply that blew up.
Title: Re: EBay power supplies boom!
Post by: AAH on January 09, 2018, 07:30:19 PM
Wow. There's a lot of energy gone into that 2nd fail. There's missing resistor leads on several components as well as the guts blown out of a couple of others  :o
Title: Re: EBay power supplies boom!
Post by: danj on January 09, 2018, 07:33:44 PM
I have been using "generic" power supplies from various vendor (e.g., HC, DIYLEDexpress, Ray Wu) successfully for four years.   Then this year three of six (out of twelve total running) grounded, causing me a long night of heartache troubleshooting recurrent GFCI tripping.   I rewired to non-GFCI outlets and they worked the rest of the season without issues.   I will be spending the $$ this year to go to MW power supplies.
Title: Re: EBay power supplies boom!
Post by: JonB256 on January 10, 2018, 06:26:46 AM
I use a lot of the cheap 12v 30amp (350w) supplies and haven't seen anything like that. (yet :) )

Your list your supplies as 60amp and that's a lot of current. Were you using them as single supplies or as part of a power injection setup? If you described their loads and layouts, I missed it.
Title: Re: EBay power supplies boom!
Post by: vipersinu2 on January 10, 2018, 07:10:50 AM
Jonb256, yes these were  60a, I used them for power injection. I used my clamp on amp meter to test current draw. I was pulling at max 30a at certain parts of the sequence. Mostly running at 20a- 24a.
I had 2 power supplies under load they would squeal like nails on chalk board.
I had one that I just unboxed, I wired up the plug, switched it to 110v. Plugged it in and boom.

Title: Re: EBay power supplies boom!
Post by: tbone321 on January 10, 2018, 09:01:49 AM
You do realize that this is NOT a 120V supply.  It is a 240V supply as indicated by the label.  170 to 240 is its voltage range and probably how it is able to put out 60A. 
Title: Re: EBay power supplies boom!
Post by: vipersinu2 on January 10, 2018, 09:49:59 AM
I emailed seller I was instructed it would be find to switch it to 110v inside, see pics of inside. there is a 110v switch and if you look at the PCB there is AC/AC/GRD or AC/N/GRD. I didnt think it would work either thats why I emailed seller.
Title: Re: EBay power supplies boom!
Post by: tbone321 on January 10, 2018, 10:41:26 AM
I believe that the seller or the person that you spoke too was probably wrong.  While the board is probably used for both 110V and 220V supplies, it is not a dual voltage board and uses different components depending on the voltage it was set up to run on.  Every dual voltage supply I have (many are knockoffs) clearly says on the label 110/220 and the switch to set the voltage is accessible on the outside of the supply and clearly labeled and almost without fail set to 220V so you don't fry the supply.  Why would they put a label on it that clearly states that the supply is a single voltage 220V supply if it is not and why make the switch so difficult to get to?  That internal switch may be used to set the wiring for the transformer based on its type, 110V or 220V and if these are single voltage transformers, who knows where you are sending voltage if you switch it to the wrong transformer type.  You may be sending 120VAC to a point that is expecting 16VAC.
Title: Re: EBay power supplies boom!
Post by: vipersinu2 on January 10, 2018, 10:42:03 AM
I just googled the model, should of done that before! But anyways it looks like it is 120v capable.


                Specifications

         INPUT SPECIFICATIONS:                                  OUTPUT SPECIFICATIONS:

         AC Input voltage range  AC88V-132V                          Rise time……...............…….……..1S typ.@115VDC

                 AC180-264V(selected by switch)                             Hold up time…….…......…….……..20mS typ.@115VDC

         Frequency                              47~ 63HZ                          Overload protection.….105% - 150% rated power,automatic recovery

           Inrush Current……..…….20A Max.@115VAC                Over-voltage protection..……105% - 150% of the rated voltage

                              40A Max.@264VAC

         Isolation……….….Input to output=4242VDC

         Leakage Current…………………………….3.5mA max

         ENVIRONMENTAL CHARACTERISTICS:                           MECHANICAL OUTLINE :

         Operating temp&humidity … -20°C~+70°C,       Dimensions..............................240Χ125Χ65mm

                       20%~93%RH(non condensing)                   Weight....................................... 2.1KG

         Storage temp&humidity ……–40°C~+85°C,

                                        10%~95%RH

Title: Re: EBay power supplies boom!
Post by: David_AVD on January 10, 2018, 01:37:26 PM
The 110V / 220V switch (or links) usually change the way the mains is applied to the input capacitors.

It is a bit odd to have a switch on the PCB with no mention of it on the outside.
Title: Re: EBay power supplies boom!
Post by: vipersinu2 on January 10, 2018, 02:23:38 PM
I wonder if it is only 60a at 220v and 30a on 110v?
if thats the case, It was being maxed out. That would explain the failure.
Title: Re: EBay power supplies boom!
Post by: tbone321 on January 10, 2018, 06:12:53 PM
That could be the case and the reason that there is no mention of it on the sticker.  They didn't want to indicate a significant drop in current output when dropping to 110V.