Power hang

Discussion in 'General Electronics Chat' started by ntom, Aug 4, 2013.

  1. ntom

    Thread Starter New Member

    Aug 4, 2013
    5
    0
    I'm having this issue of power hanging and not powering a network router on a tower from time to time.

    Let me first explain the system:

    First there is an AC adapter (24V, 2.5A) connected to a 220V power grid. I have cut the adapter's connector and have attached a 60 meter two threaded cable to the adapter which runs to the tower and powers the network router with the adapter's jack I attached to the other end of the cable.

    It all works great and I'm not getting any voltage loss because I'm getting the full 24 volts. But occasionally, without any clear reason the adapter stops giving power or the router is not powered. It's as simple as unplugging the jack from the router and re-plugging it that starts the system again.

    Sometimes this doesn't happen from 2 or 3 months, sometimes in a matter of days. It's a real issue since I would have to climb to the tower just for this or strip the connection of cables at the adapter's end and attach them again which also does the trick of un-hanging. But just unplugging and plugging the adapter again doesn't do the trick.

    I appreciate any help or advice.
     
  2. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    The first thing I would do is to solder the connections. If you want convenience, add a small switch (momentary off push button) to the line so you just need to flip the switch to reset.
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,414
    3,353
    I don't think the problem is in the AC adapter. Sounds like the router hangs and you have to cycle the power off and on again. Try changing the router.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,085
    3,024
    Wireless routers are notorious for overheating. Try propping it up to increase air flow around it.
     
  5. ntom

    Thread Starter New Member

    Aug 4, 2013
    5
    0
    I don't think it's because of overheating because as much as I can remember this is only happening during the night when there is not much load. I can't replace the router right now but I have tried different adapters with the same results. I always assumed it has something to do with the power line. I'm going to have to check with the router's manufacturer forums or support also for any clue if anyone else has experienced any similar issue.
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,085
    3,024
    I've also heard of routers shutting down due to excessive wall wart voltage. Some Netgear routers shipped with wall warts that delivered far more than the rated voltage, even when loaded by the router. It was an easy fix but it was users that figured it out. Maybe your wall wart is OK, but perhaps your router is seeing an occasional surge due to your long cable?
     
  7. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    1,758
    98
    Huh, why do you have to climb a tower to reset your router?
     
  8. ntom

    Thread Starter New Member

    Aug 4, 2013
    5
    0
    Because sometimes I don't have access to the wall plug. I didn't need an inline switch because it was not a big of an issue and I needed to fix the problem really not just patch it.

    About the surge I don't know if I might be able to detect it, it might be that but shouldn't it work again only by just re-plugging the adapter to the plug? As I mentioned earlier I have to unwire the cable and wire it again to "unblock" it.
     
  9. WBahn

    Moderator

    Mar 31, 2012
    17,715
    4,788
    That really doesn't make sense (having to disconnect the power at the router). What happens if you disconnect the cable at the adapter end?

    If you cycle power on the adapter, how long are you waiting before you turn power back on? The voltage might need some time (many seconds to perhaps a half a minute or so) to drop low enough for the router to reset.
     
  10. ntom

    Thread Starter New Member

    Aug 4, 2013
    5
    0
    The router actually has overvoltage protection kicking on at 28V which shuts down the router before bringing it back on when the voltage is stabilized. I don't remember I have ever tried to wait couple seconds before reconnecting the adapter, but I would always undo the cable connection which would take a minute or two before plugging the adapter again.

    Maybe the overvoltage protection is stopping the current flow on the router but it's not aware when the voltage has stabilized thus remaining in that state indefinitely?

    The router we're talking about is this one:

    http://routerboard.com/RB433AH
     
  11. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    1,758
    98
    Have you considered putting a small mains UPS on it? It's more a small LAMP server than a router. What are you using for a power supply now?

    Why not add a 60m mains extension cord to the power supply vs running a 60m power cable (which is most likely the problem). Why are you running a router 60m from a mains power source?
     
    Last edited: Aug 5, 2013
  12. ntom

    Thread Starter New Member

    Aug 4, 2013
    5
    0
    It's a security concern, can't run a 220V line to a tower which is an easy accessible area.

    I've tried putting a UPS, still the same. I'm using AC adapter, tried different one, they're reliable.

    Why do you reckon the problem lies to the cable? The cable's thick enough to transfer 24V without loss at 60m and I've changed it recently.
     
  13. westom

    Member

    Nov 25, 2009
    52
    5
    Did you measure 24 volts at the router with the router consuming power? If voltage is lower (and depending on another power supply inside the router), then a router could demand more current. Thereby causing the power supply to intermittently trigger its foldback current limiting function. Disconnecting would reset that safety feature.

    Measure voltage even when the failure occurs (and before disconnecting anything) to eliminate a long list of reasons traceable to that power supply or 60 meter wire. A power supply could be failing (implementing safety features) due to other reasons (besides a 60 meter connection). No useful answers are possible from your 'changes' and without those hard numbers. You do not even say how you measured 24 volts. Or current draw as measured with a meter. Or if a LAN port is powering another device (POE). Critical details.

    Also essential is how that tower is grounded with respect to building ground. And how router connections are isolated from the tower. Plenty of necessary details are not provided.
     
    Last edited: Aug 6, 2013
  14. inder123

    New Member

    Aug 7, 2013
    3
    0
    When your AC router make some sound you should see it, because some of time voltage high or low.
     
Loading...