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A basic voltage
reading only tells a small part of the story. Most UPSs only 'fix' the voltage
if it is outside of a predefined range. Mid priced supply a constant voltage
from an inverter and battery while always charging the battery. While the
voltage is fairly stable the waveform of that voltage is crude. The APC I
recomended is an always on design with true sine-wave output. This is important
for problem line voltages. Other power quality issues that a voltmeter can't
show is harmonics, fast transiants, frequence, spikes, sags, current loading and
more.
Another thing you
may want to look at is static. In dry, windy conditions, the air moving over
your data lines will create high static voltages. Since the water tower is
painted there is no easy way for that static to disipate. Are your data lines in
metal conduit? Is it grounded. Even though the radios cases are plastic and the
metal mounting tabs have no electrical connection to the electronics, grounding
the mounting tabs on the radio and entry seals to the NEMA box will help to
reduce static on the cases and wire. If your wires are no in conduit, make sure
they are securly attached to something so that there is no movement of cable on
any surface. For severe conditions (like a water tower in the Texas summer :-) I
would even reccomend making a wind break/sun shield that shields/covers your
NEMA box and radios. A PVC box will produce A LOT of static. Use a metal box if
possible, if not, line the inside with foil and wrap a small guage wire around
the outside of the box several times, fold one end inside the box to touch the
foil and then ground the other end.
I know this
sounds like a lot of work, but static is a major radio killer that is very hard
to track down. Power Line quality and static on transmission lines are probably
the two biggest mystery killers is our field.
Just got back from the water tower. We replaced the old
power strip with two new ones (didn't have one big enough for all the power
supplies). Unfortunately, that wasn't the problem. One of the sb
power supplies was plugged directly into the UPS, not the power strip, and it
was locked up. So we know the power strip was not the problem.
Checked the voltage at the output of the UPS for about 20 minutes and it was
rock solid at 117.5V, never fluctuated more than .4V. Of course we would
have to put a power recorder on it to test for 24 hours to see if anything like
a pump cutting on is causing a large spike or drop, but the UPS is supposed to
filter out the majority of that. So basically, we are back at square
one. It has to be either power related or heat related since we replaced
one of the radios and that didn't help, or all the radios that have come out of
SB since June have the same tendency. Which I really doubt. So still
open to ideas. We are going to try and get some sleep while they are all
up before something goes down again and the phone calls start up
again.
Thanks to everyone for your help - and keep the suggestions
coming,
Gloria
----- Original Message -----
Sent: Saturday, August 23, 2003 10:17
PM
Subject: RE: [smartBridges] help with
APPO problem
Is the power
strip also a surge protector? You only want one AC surge protector inline with
your devices. Use a power strip that is only a power strip (like an AC
splitter). Having two surge supressors in line has a strange effect of making
each one LESS effective by tricking the other in to thinking the surge is not
as bad as it really is and letting more noise through.
Actually, my tech and I are discussing power issues right
now. That seems to be the most likely culprit at this point. I
think we are going over to the water tower and change out the power strip and
see if that helps. All the POE's are plugged into the same power strip
which is plugged into the UPS. Our Trango has not burped once and it is
plugged directly into the UPS. Maybe our power strip is noisy or has a
bad ground. Will let you know what we find when we get back from the
tower.
Thanks for all your help - I sincerely appreciate
it,
Gloria
----- Original Message -----
Sent: Saturday, August 23, 2003 8:39
PM
Subject: Re: [smartBridges] help with
APPO problem
Do NOT rule out power. It could be a little too high
or a little too low and MOST ups units won't compensate for
that.
Also, if there are large pumps there it's quite likely
that you are getting intermittent brownouts that the unit won't quite kick
in for.
See if a local electrician has a voltage recorder.
We saw many VERY strange copier problems caused by power
issues.
It seems VERY strange that FOUR units would all do the
same thing at the same time. I've used 3 or 4 of them of late and had
NO bad ones. Only a dead eithernet port but that happened after a
wicked lightning storm and we also lost a computer nic card on that same
system so I'll not blame sb for this one.
I'm home if you want to call and talk about some of
this. The office line rings here too.
509.982.2181
marlon
----- Original Message -----
Sent: Saturday, August 23, 2003 6:31
PM
Subject: Re: [smartBridges] help with
APPO problem
It just keeps getting better. Now three of them
are down, which means only one is up. We know for sure now that it
is not the POE, the power supply, or the radio, unless the one I got in as
a replacement has the same problem as the one it replaced, which is highly
likely. Either all the APPOs have the same problem, including the
ones that are still shipping, or we have some kind of weird power
problem. Since everything is plugged into a UPS, I don't see how it
could be power, but I am not ruling out anything at this point. Now
I just have to try and convince the only tech on duty tonight to
climb the water tower again. This makes six nights in a row that he
has had to climb that damn tower. I know, I know we should have
designed it with things on the ground, but we didn't know we were going to
have this much trouble with the equipment, and we were trying to make the
city happy and keep everything as unobtrusive and out of sight as
possible. It is too late to redesign the whole system, we don't have
the money to start all over.
Gloria
----- Original Message -----
Sent: Saturday, August 23, 2003
8:03 PM
Subject: Re: [smartBridges] help
with APPO problem
Get a couple of 100' high grade extension cords.
Put your ups unit on the ground and when you need to reboot them just
pull the plug for 10 seconds.
Not a good fix but better that what you have till we
figure out what to do about the ap's....
marlon
----- Original Message -----
Sent: Saturday, August 23, 2003
11:39 AM
Subject: Re: [smartBridges] help
with APPO problem
Marlon,
My AC runs up the water tower from a breaker at the
base of the tower. There is an AC outlet in my NEMA box with the
UPS plugged into it, a power strip into that, with all the power
supplies and the D-Link switch plugged into that. All the cat-5
is outdoor rated, shielded and gel filled, all cables tested with a
cable tester after being built up on the tower. As for lightning
arrestors, we haven't had any sign of lightning or a drop of rain in
months - this is north Texas where rain doesn't exist from June until
October. I don't see how I would run a power cord down the
tower, it just doesn't seem possible. We can try moving the
cat-5 cables around to different ports on the switch to see if it is
one port on the switch that is failing, but since we have had two
different units fail now with the same exact problem and they are on
different ports, I don't think that would tell us much.
Any more ideas - I am always willing to listen and
try different things,
Gloria
----- Original Message -----
Sent: Saturday, August 23, 2003
1:00 PM
Subject: Re: [smartBridges]
help with APPO problem
First off, run a power cord to the bottom of the
tower for a bit so you can just unplug it to reset everything
;-).
If multiple units are seeing failed eithernet
ports you might need to look at your switch. Also, might want
to make sure you have good lighting arrestors on the cat 5
ports.
In almost 4 years of this wisp stuff I've only
lost a couple of ethernet ports and both of those were at the same
place and on the same linksys cable router.
Until this fall. We lost two sb radios with
dead ethernet ports durning a storm. One ap and one
client. At one location the homeowner also lost the ethernet
port in the dell computer. At another location all radios are
fine but the customer lost a nic in a dell computer.
I'm thinking that there may be some crappy
ethernet ports on the market?
marlon
----- Original Message -----
Sent: Saturday, August 23,
2003 9:50 AM
Subject: Re: [smartBridges]
help with APPO problem
Marlon,
I don't have any spares here. The only
extras I have are the one we took down night before last that we
thought was bad, and an indoor that was sent to me instead of an
outdoor.
We replaced the POE with a known good one on
Wednesday night, we replaced the radio itself Thursday night, and
replaced the power supply last night. So far it is up, but
it usually takes about 24 hours for it to go down.
Now a different one is down - same problem -
dead Ethernet side, can't talk to it. This is the first time
this one has gone down since we put them up three or four weeks
ago.
If you have any more ideas, let me know. I
am willing to try anything at this point, if my techs don't quit
because they are sick and tired of climbing the water tower every
night to either reset something or replace something.
Thanks for your help,
Gloria
----- Original Message -----
Sent: Saturday, August 23,
2003 10:24 AM
Subject: Re: [smartBridges]
help with APPO problem
You have other ones there right?
First, swap ethernet ports on the
switch. Swap power supplies and then power injectors (I
just had a bad power shot) with a known good working
unit.
If none of that works, swap the ap with a
known good working unit. If the problem moves, yep, really
bad luck! If the problem stays with another radio, it's
environmental.
I know when we first got started we were on
one end of a 30 mile ptp wmux link. It would totally shut
down my radio. Similar to what you are
seeing.
Call me and let me know what you find or if
you'd like to talk about this a bit more.
*Time to learn those trouble-shooting
techniques ;-)*
marlon
509.988.0260 cell
----- Original Message -----
Sent: Friday, August 22,
2003 6:30 PM
Subject: [smartBridges]
help with APPO problem
Anyone got suggestions as to what is causing
one of my APPOs to go down? We have had to climb the
water tower and reset it three times in the last week.
We replaced the POE on Wednesday and it went down again
Thursday. I ordered a new unit overnighted and replaced
the unit last night. It worked great all day today, but
is down again now. The outdoor rated cat-5 run is only
about 20 feet, the cable was tested with a cable tester before
putting it in place, everything is water proofed (even though
we haven't had rain in months). What else is
there? The POE was replaced, the entire unit was
replaced, and we still have the same exact problem. When
it does this, the Ethernet LED is off, the Power and TXRX LED
is on solid, and we have no communication with it. Did I
get so lucky as to get two bad units with the same exact
problem? The only item that has not been replaced is the
power supply - could that be bad? All the other units on
the water tower are working fine since I upgraded the firmware
last Sunday. They are all plugged into the same switch,
which is plugged into a UPS and all of it is in an air
conditioned NEMA box.
smartBridges tech - or anyone -
help!
Thanks!
Gloria
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