Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[burakkucat]

I do have a DIN-mountable 240V>12V power supply in the loft which I'd like to try, however looking at it's spec sheet it has active PFC and I'm not sure if this will interfere with the UPS? The manufacturer does say not to put surge protectors on either the input or output, but nothing specifically about an active PFC PSU.

   Hmm . . . I would be cautious to the point of not using an active PFC PSU with a UPS!

[crgbt]

  Hmm . . . I would be cautious to the point of not using an active PFC PSU with a UPS!

My knowledge of electronics isn't the greatest, so I'll take your advice! If I do want to rule out the PSU, I will simply wire it to the mains rather than via the UPS

Thanks,
crgbt

[burakkucat]

My caution is based on your earlier statement that your UPS is at the more "basic" end of the spectrum. As such, I suspect it is not a true sine wave output but a simulation . . . possibly "multi-square wave", which looks like the side view of a stair-case.

[crgbt]

My caution is based on your earlier statement that your UPS is at the more "basic" end of the spectrum. As such, I suspect it is not a true sine wave output but a simulation . . . possibly "multi-square wave", which looks like the side view of a stair-case.

Ah, right! Well, it's marketed as having a 'Pure Sine Wave' but I have no equipment to actually test that statement

Best to err on the side of caution, I think!

crgbt

[sevenlayermuddle]

Re temperature, it’s tricky.

Hypothetically, suppose a device cabinet is sitting at (say) 5C above ambient.   I’d suggest that most probably, that 5C rise will be attributable to heat radiating from an internal ‘focal point’  that is much more than 5C above ambient.

I’ve never been involved in the technology of ventilation and cooling, so certainly no expert.  But my suspicion is that it may actually be quite a complex area, there may be more to it than meets the eye.   

Beyond that, sorry, I don’t think can offer any specific advice.

[crgbt]

Re temperature, it’s tricky.

Hypothetically, suppose a device cabinet is sitting at (say) 5C above ambient.   I’d suggest that most probably, that 5C rise will be attributable to heat radiating from an internal ‘focal point’  that is much more than 5C above ambient.

I’ve never been involved in the technology of ventilation and cooling, so certainly no expert.  But my suspicion is that it may actually be quite a complex area, there may be more to it than meets the eye.   

Beyond that, sorry, I don’t think can offer any specific advice.

That makes sense. I’ll make plans to try and relocate the UPS as it’s the item putting out the most heat by far - the router, modem and raspberry pi are almost cool to the touch compared to it.

I’m no expert in that area either, but we’ve got to try these things and learn the hard way 

crgbt

[sevenlayermuddle]

Forgive me if you’ve already answered this but in any of the deceased devices, were there visible signs of failure with the lid removed?

Obvious examples would be bulging capacitors, blackened areas of pcb, charcoal deposit on tracks, skeletal remains of evaporated components, etc.

Don’t assume I can help if the answer is ‘yes’, but it might provide inspiration as to wherever lies the weakness.

[Weaver]

Apologies for off topic-ness, but I would just like to give out a very warm welcome to our new users.

Welcome to users crgbt and hopkins35.

FYI I am a fellow A&A and Firebrick FB2900 / 2700 / 2500 user. I also have a lot of ZyXEL VMG1312-B10A modems - more than half a dozen - four in service now plus lots of backup units. I tested a Vigor 130 but only briefly as it was a little bit slow for me, however I am ultra long ADSL - not VDSL. I have four lines each 4.55miles. I am running an FB2700 with an FB2500 ready as backup. I have an FB2900 but I have not got it set up yet.

[crgbt]

Forgive me if you’ve already answered this but in any of the deceased devices, were there visible signs of failure with the lid removed?

Obvious examples would be bulging capacitors, blackened areas of pcb, charcoal deposit on tracks, skeletal remains of evaporated components, etc.

Don’t assume I can help if the answer is ‘yes’, but it might provide inspiration as to wherever lies the weakness.

I've had a look and couldn't see anything obvious. I was surprised by how little there was inside actually, it's majority heatsink! If you want to take a look yourself, I've uploaded a picture here: https://i.imgur.com/TzoDQii.jpg

Apologies for off topic-ness, but I would just like to give out a very warm welcome to our new users.

Welcome to users crgbt and hopkins35.

Thanks Weaver

FYI I am a fellow A&A and Firebrick FB2900 / 2700 / 2500 user. I also have a lot of ZyXEL VMG1312-B10A modems - more than half a dozen - four in service now plus lots of backup units. I tested a Vigor 130 but only briefly as it was a little bit slow for me, however I am ultra long ADSL - not VDSL. I have four lines each 4.55miles. I am running an FB2700 with an FB2500 ready as backup. I have an FB2900 but I have not got it set up yet.

I did notice the quite impressive setup in your thread about line issues (https://forum.kitz.co.uk/index.php/topic,23742.0.html) and I was going to ask if I could drop you a PM and put some questions your way re: multiple lines on an FB with A&A, if that would be okay?

Also, as way of an update for this thread too, I'm onto my first alternative firmware for the Vigor 130 whilst I wait for the VMG1312-B10A to arrive.

[sevenlayermuddle]

Hmm, so if if I have this tight the evidence is that these devices all suffer some kind of hardware failure after a few months.   It always manifests itself the same way, as high error rates, yet the device never quite dies completely, and there’s no obvious signs of stress?

If that understanding is right, I’d be starting to think outside the (modem) box.  What else, other than modem failure, could give rise to the same symptoms, and yet always appear to be fixed by installing a new modem?

One possible thought that occurs is the modem lead.   If the lead’s terminals have become degraded or dirty it might conceivably work ok-ish on a ‘factory fresh’ brand new modem with sparklingly clean terminals in the sockets and full spring tension.  But then worsen over time as the modem contacts lose a tiny bit of tension, and begin to oxidise themselves.     Just a thought?

Another suggestion might be along the lines of surge-arrester technology, and overlapping with discussions earlier in the thread, with B’Cat.   Some surge arresters suffer progressive degradation with each arrest they make, and eventually short-circuit.  I also vaguely recall  that some UPS can present a waveform to connected equipment that can cause frequent ‘false arrests’ to be made, hence degradation and early death of surge arresters within that connected equipment.   That really is a long shot, as I’d expect the modem to fail completely (blow a fuse) if a surge arrester on the supply shorted.   But mentioned again, just as possible inspiration...

[Weaver]

@crgbt I would be absolutely delighted to answer any questions as best I’m able. However I would very much prefer to answer in a thread with some very general title of your choice as that way other users can benefit. Also you might get answers faster because it sometimes takes me forever to reply.

[crgbt]

@crgbt I would be absolutely delighted to answer any questions as best I’m able. However I would very much prefer to answer in a thread with some very general title of your choice as that way other users can benefit. Also you might get answers faster because it sometimes takes me forever to reply.

Sure thing Weaver, I’ll start a thread later today. I’m not sure if I should open it under broadband hardware or broadband technology as I have questions about both! Will open it in this section I think Appreciate any advice you can give.

Thanks,
crgbt

[crgbt]

Hmm, so if if I have this tight the evidence is that these devices all suffer some kind of hardware failure after a few months.   It always manifests itself the same way, as high error rates, yet the device never quite dies completely, and there’s no obvious signs of stress?

If that understanding is right, I’d be starting to think outside the (modem) box.  What else, other than modem failure, could give rise to the same symptoms, and yet always appear to be fixed by installing a new modem?

One possible thought that occurs is the modem lead.   If the lead’s terminals have become degraded or dirty it might conceivably work ok-ish on a ‘factory fresh’ brand new modem with sparklingly clean terminals in the sockets and full spring tension.  But then worsen over time as the modem contacts lose a tiny bit of tension, and begin to oxidise themselves.     Just a thought?

Another suggestion might be along the lines of surge-arrester technology, and overlapping with discussions earlier in the thread, with B’Cat.   Some surge arresters suffer progressive degradation with each arrest they make, and eventually short-circuit.  I also vaguely recall  that some UPS can present a waveform to connected equipment that can cause frequent ‘false arrests’ to be made, hence degradation and early death of surge arresters within that connected equipment.   That really is a long shot, as I’d expect the modem to fail completely (blow a fuse) if a surge arrester on the supply shorted.   But mentioned again, just as possible inspiration...

Thanks for the suggestion sevenlayermuddle. I think I've swapped the cable once before but I'll dig a fresh one out and give it a try too. Regarding the surge protector/arrestor, the only one in the path now is built into the UPS which is new(ish), and was bought to see if this issue was related to power surges/high voltage - unfortunately I don't have an oscilloscope to check the sine wave it's outputting, but it's marketed as outputting a pure sine wave.

I was discussing with jack21 about using a non-standard 12v PSU (this is the one I have I think: https://uk.rs-online.com/web/p/din-rail-power-supplies/7654657/) and plugging it in direct to the mains and seeing if that can rule out anything on the UPS and the standard wall plugs. That's another thing to try out

Thanks,
crgbt

[jack21]

Wow, that's quite a hefty bit of kit.....enough to power half a dozen modems if/when you get that many!!
If I was giving that a trial, whether direct from mains or via a UPS, I'd put a 2A fuse in the feed to the modem (as I do if powering from a 12V battery) just to feel a little safer.
And I think your wish to relocate the UPS to outside the kitchen cabinet is very sound.

[sevenlayermuddle]

Some appliances contain a built-in surge protector, in the crude form of a varistor across the mains supply, after a fuse.  If the mains voltage momentarily exceeds a threshold, the varistor absorbs absorbs the surge.   If it's more than momentary, or the varistor shorts, the fuse blows. 

I simply don't know if the modem power brick will have built-in varistor protection.  I vaguely thought power bricks often do, but despite having spent an obsessive amount of time googling the topic, I can't find any evidence that I'm right.

In any case I'd really not dwell on it.  I can argue a case that hypothetical scenarios might exist that would cause a varistor to fail on a regular basis every few months, owing to a badly behaved UPS.   But since the fuse should then blow, that failure mode would cause the modem to become completely dead and bricked, rather than limping on weakly.