Enermax Liberty ELT620AWT

[starfury1]

Re: Enermax Liberty ELT620AWT

Also just out of interest
has anybody had one go flash bang on 230VAC? (on UPS or otherwise)
OH BTW I take it the UPS are 110/120VAC@60Hz?

[PCBONEZ]

Re: Enermax Liberty ELT620AWT

On a ship?
Ship power is hard on electronics gear.

When they parallel generators to shift loads the frequency cycles up and down a few times. Frequency cycles are WAY worse than a sudden power out. It's like a whole bunch of brown-out/brown-in power excursions one right after another.
-
Some of our critical gear was powered by inverters run off 400 Hz motor-generators with auctioneered 60 Hz power to their motors. The rotors in the generator end were built extra heavy so the inertia would minimize speed fluctuations even if the 60 Hz in from the auctioneers did cycle a little.

.

[starfury1]

Re: Enermax Liberty ELT620AWT

yeah from memory thats were the first one she had blew
How big it was etc, I don't know the exact details
I don't think it was getting a work out either at the time, it was idle I think but could be wrong

the post is on another forum
Gal or even me may have linked it on BC forums somewhere... not sure now ...it was a fair while back..like a year plus

Reading mutants post on it, it seems it had a failure while on the UPS but I am wondering how bad it was as it seemed to really flash bang on mains...I wonder if the UPS may have some what protected it from the fireworks display
since it over loaded and I assume UPS shut down.


Anyway Id be vary wary about using them with an UPS or bad mains supply.

Cheers

[mutant]

Re: Enermax Liberty ELT620AWT

I do believe that my UPS stopped powering the powersupply when the powersupply faulted. It was telling me that the UPS was overloaded. I am connected to 120V 60Hz. Your theory about the UPS possibly being the cause makes me wonder. Even so, shouldn't manufacturers take into account when designing a powersupply that some people connect to a UPS? At the minimum they should at least have in the manual or on the box a warning.

My UPS when using the battery is a stepped sine wave. As far as I know it's output should be the same as connect straight to the outlet until the power fails and the battery kicks in. But I'm no expert at these things.

I should have held off connecting power back on and taken it apart and have you guys tell me what to look for. But hindsight is 20/20 hehe.

[Rubycon]

Re: Enermax Liberty ELT620AWT

I'm the one on a ship. Our power is very good even on the non essential circuits - as good as utility power. No complaints from anyone depending on a 60Hz AC clock as far as keeping time.

We have dedicated circuits for computer power which are protected by ferroresonant technology. Power is very clean and well regulated and monitored by Dranetz monitoring equipment. If there is a mains generator issue the UPS system will engage and the flywheel system keeps power flowing until the backup generator starts. If there is a backup generator problem batteries will power an inverter which is switched into the primaries of the ferroresonant transformers.

What this all boils down to is this: The computer systems ALWAYS receive a continuous supply of very pure 60Hz sine wave power at 240VAC or 120VAC. My Liberty that failed was running at 240VAC. It made no noise. I had no idea anything was wrong until I smelled smoke. When the power supply was removed and connected to a DMZ outlet what a show it put on! I would most definitely NOT want that thing sparking and crackling like that in my PC.

I could not tell you about stepped sine UPS' as we don't have them. But this thing failed in pure sinewave power that never deviates more than 5% on voltage and less than .05% frequency and THD is always less than 1%. If that's not good enough then it might as well be a firecracker power supply. It was bad enough that when I originally built the system it would not start due to the "RF anomaly" apparently caused by the APFC. Then it blows up six months later. The chief engineer is not amused despite my charm and sense of humor.

IIRC Minerva is in the States in NC. She posted a few days ago on jonnyguru.net/forums about a 1600W PS with a start up smell. That must be a beast of a power supply. Honestly I'm looking for something bigger than my 700W Seasonic because it runs too hot and makes me nervous. She posted that her system is pulling almost 1kW on a kill-a-watt which seems monstrous. But it looks like that PS can take it given the specs - 117A on 12V.

[PCBONEZ]

Re: Enermax Liberty ELT620AWT

That's nuts:
On 115v 1600w is enough to require a dedicated 15 amp circuit to the breaker box just to run a PC.

Green Peace is going to be going after home computers any time now!!!!

[starfury1]

Re: Enermax Liberty ELT620AWT

Rubycon

then it might as well be a firecracker power supply.

Well there's a good potential for that!

Humm yeah maybe I should be a little clearer on that with the sine wave UPS and Inverters

I think their statement was it "should be used with a sine wave UPS (or maybe it was inverter) only."
(I'll stand to be corrected on that thought)


but the real question is
why do they flash bang, what causes or triggers this failure?
we still don't have a conclusive answer on this.

Until we do any liberty is a potential failure risk.

My original "guess" (posted somewhere around here) was that possibly some phase relationship was causing the APFC or associated circuit to go into some race, runway condition.

Edit ok just found it re read it, I was thinking from start up, but a further thought is that possibly this might be happening when the ups switches in. there has to be a finite time when the psu is "free wheeling" if its using the mains sinewave input as a reference point of some kind
(and yes Ideally it should have some why of re-stabilizing anyway)

but I am afraid I am in no way any type of expert on APFC circuits etc so have no real theory as to how or even if this could happen.

so it remains somewhat of a mystery, all you can say is liberty supply is potential an unreliable supply.

I have seen a post or 2 on the Galaxy line failure but has anyone seen any on the Infinity Series?

just my demented ramblings

Cheers

Oh PCBONEZ I hear that in OZ the latest piece of brilliant thinking is to try and ban linear wall warts (transformer jobs) and use switcher wall warts to save on green house gas...this I am told will help save the planet
well the story goes something like that

[PCBONEZ]

Re: Enermax Liberty ELT620AWT

starfury1 - Some nut here wants to ban Christmas lights being put out more than 10 days before or two days after Christmas.
[Also wants to send people to jail for a third offense.]

~~

(Assuming 60Hz at the start.)

On a 'straight' power out frequency goes from 60Hz->Zero fast.
The APFC doesn't have time to get over worked before the power is just gone.

On a 'brown out' the frequency change is much slower.
The frequency goes 60Hz->59Hz->58Hz->57Hz->56Hz-> and so forth.
The APFC is trying to compensate and if not well designed it (components in it) will overheat.

A good APFC will have a cut-off threshold.
A point at which it gives up and switches off.

So there is my guess:
Perhaps these Liberty units don't have a threshold and try to correct all the way down to zero Hz (and in doing so they overload) or perhaps they have a threshold but the cut-off setting is a bad choice (same result).

.

[Nuno]

Re: Enermax Liberty ELT620AWT

Hi boys...my Enermax liberty 400w feel bad...! I have raplace two k2698 on the primary switching with two irfp 460 (ch N 500v 20A 0,3 Ohm 150w)..but I need to know the value of Ntc resistor because "it is dowing in FLAMES"!! I know Ntc resistor value is the same for all kind of liberty....!

Thank you for your support...

[trodas]

Re: Enermax Liberty ELT620AWT

Well, you are in luck, because I just working on repairing my second Enermax Liberty 620W PSU and I have it opened/I will open it more times

I already recapped first one with Samxons completely and it run just perfect:

Enermax 620W -done-
---------------
1x 390uF 400V d25 x 45 - not need, good HP3 cap, great specs
4x 3300uF 10V d10 x 34 - 4x Samxon GD 3300uF 6.3V d10
2x 3300uF 16V d10 x 34 - 2x Samxon GD 2200uF 16V d10 (GD must make it
1x 1500uF 10V d10 x 23 - 1x Samxon GC 1500uF 10V d10
1x 1000uF 10V d8 x 18 - 1x Samxon GC 1000uF 10V d8
1x 470uF 25V d8 - 1x Samxon GC 470uF 16V d8 (highest spike 14.4V)
1x 22uF 50V - 1x Samxon GF 22uF 50V d5
5x 10uF 50V - 10x Samxon RS 10uF 50V d5

...so just tell me witch resistor you want me to read on. I have no idea what "Ntc" one you mean. Near the primary K2750 stuff are R1 resistor (on the side) and it goes "brown, green, gold, gold" witch should be 1,5 ohms. In doubt I cna desolder it and measure.
If you mean the resistor just bellow the first input switchers heatsink (also damn close to the K2750), then this is R15 and goes "green, gold, silver, blue" witch is not decodable for me...

[starfury1]

Re: Enermax Liberty ELT620AWT

I thought Since KC8 had posted this I would link the threads

So after much discussion (High flutin theories, mainly from me)
time, heat aged (it becomes Conductive) Glue is the culprit

A BIG THANK YOU KC8

see this thread

https://www.badcaps.net/forum/showthread.php?t=5466

Also I looked for info on the controller chip a while back but didn't find anything
so thanks to Latoof

I have finally got some good news on the PSU...



The Fairchild SG6520 is a direct replacement for the PS223 so have a couple on order from Mouser elec in the US and should have them in a couple weeks

See thread, and please read it for further info on this, as there is a quirk of some kind
(I haven't read it properly yet)

https://www.badcaps.net/forum/showth...9&page=1&pp=20


On the clue issue

I am not 100% sure, I don't remember seeing any on mine
but them again I wasn't looking for it and yeah
I will have to check mine (dreads thought)
(its hard to see the bottom of the legs)

lastly I do remember one post over at the OC forum (from memory) of a 1KW Enermax beast going BOOM so wonder if it the same issue??

Cheers all