Sorry it took so long for the summary folks, but you know how busy things
get...
A while back, I asked about the possibility of our old Sun 3 machines catching
fiire if a fan failed:
>We've got a few Sun3 machines, no longer on maintenance, sitting down the hall
>in an unoccupied room. I've been asked to find out what sort of fire hazard
>these machines represent. When they were our main workhorses, they sat in an
>air-conditioned room, and all was fine. They've now been retired from
>mainstream use, but are still handy as backup servers. Anyway, they no longer
>have their air-conditioned room, and are reliant on their fans. So if the fans
>fail, are they going to overheat, and "stop", or just Hang And Catch Fire?
>We're going to ask Sun for their opinion, too, but it's always better to have
>a wider view. I'll summarise, as usual.
>
>Specific information:
> 3/180 rack, with two disks
> 3/160 pedastal, uses the rack for disk and power
> 3/160 pedastal with disk
The overall consensus was that the chance of them actually damaging anything
else was pretty minimal - they'd overheat, choke, and stop working, sure,
but not actually *catch fire* (unless we were really unlucky).
Sun weren't quite so encouraging. After a bit of musical phones ("we don't
deal with that sort of thing here," and "You want to know WHAT?" etc), I
spoke to one guy who said we were "doing a good job of making them obsolete".
While they won't burn, quoth he, they'll cook, and thereafter be so unreliable
as to be completely useless. Unless it's a cold winter and we need some more
heaters.
Alright - so they're not a fire risk. Probably. I don't know yet whether tha
"probably" is good enough for our Health & Safety people. But from a systems
point of view, if nothing else, I'm going to see what I can do about getting
that room cooled, conditioned or ventilated.
Thanks to all that responded. Relevant quotes from replies appear below.
Keith.Bierman%Eng.Sun.COM@gec-epl.co.uk (Keith Bierman fpgroup)
bernards%ECN.NL@gec-epl.co.uk (Marcel Bernards)
Arie Bikker <aribi%geo.vu.nl@gec-epl.co.uk>
marke%violet.berkeley.edu@gec-epl.co.uk
Mark Ferraretto <mferrare%physics.adelaide.edu.au@gec-epl.co.uk>
jayl%bit%Sun.COM@gec-epl.co.uk (Jay Lessert)
eeimkey%eeiua.ericsson.se@gec-epl.co.uk (Martin Kelly)
Nigel Mitchem - System Support <nigel%uk.ac.city.cs@gec-epl.co.uk>
James Pearson <jcpearso%ps.ucl.ac.uk@gec-epl.co.uk>
Hugo.Tafel%West.Sun.COM@gec-epl.co.uk (Hugo Tafel - South Bay SE)
unruh%physics.ubc.ca@gec-epl.co.uk (William Unruh)
cyerkes%jpmorgan.com@gec-epl.co.uk (Chuck Yerkes)
---- Message 1 ----
I cnnot tell this for these 160/180 machines, but if you let the air inlets
of a 3/50 , 3/60 or 4/110 get dirty the machine will finally creash due to
chip heating. Also disk units are sensitive for overheating.
I have had quite a few old shoeboxes of which the air inlets were covered with
dust. Finally those disks died.
I had a 3/50 once which cought fire on the CPU board. on the board is a voltage
converter for RS232 negative voltage, and that thing burned out.
You can't imagine the smell of a dead computer, yech !!
---- Message 2 ----
I have never seen a Sun3 halt and catch fire; I have seen them run
sans fans, I have seen them cease functioning, I have seen wires
aribtarily bridged (honest, I didn't mean to do it!) and etc.
Short of tossing wires across the power supply, I've never seen them
do *anything* exciting.
Generally speaking, if the room is comfortable enough for humans, it
probably isn't what I'd consider a hazard.
But then, I ride motorcycles; so ask an expert.
---- Message 3 ----
I think we have the awnser you are looking for. We have a pile of 6 3/60's squeezed in
a 19" cabinet together with 12 1 Gbyte 5.25" hard drives. Total power use of the cabinet
is in the order of 2 KWatt. There is a forced air stream though the cabinet which stands
in a closed room with only minor cooling. This summer was very hot in holland and we did
have a problem. No fire, but memory errors causing panic, crashing etc.
We found that the 3/60's were running to hot (50 degrees Celsius chassis temperature)
caused by clogged air filters (perforated metal sheet under the blower). Cleaning of these solved our problem and they are running fine again.
This shows that a 3/60 can a). stand a lot of heat and b). will start vomitting before
it catches fire.
---- Message 4 ----
I have had a 3/160 pedestal (rollabout) with 10 VME cards in it, as
well as two SCSI disks and a tape drive, in an 75-85 DegF room for
about ten months. The computer keeps running, and so do the fans, all
six of them.
Our experience at Berkeley is that the fans usually start to make a
fair bit more noise before they fail, and make the extra bit of noise
for weeks or months before failure, if they manage to make that final
step (and actually fail). The noise is especially evident as a sort
of grating sound when the machines are being powered-down.
I would not worry about it. Anyway, what could burn? Do you keep
these computers in your paper-storage closet?
[ Nah - in our long-term, high-security dump tape room:-) -Steve ]
---- Message 5 ----
We used to have 3 3/60s along with a number of terminals in an
un-airconditioned room. When it got too hot the machines would just stop.
I never had any one come close to catching fire. It would get up to 38 deg C
in the room too.
---- Message 6 ----
We had one Sun 3/60 that blew a chip on the main CPU board. It heaved
and puffed a lot of smoke but it didn't catch fire. It was unbelievable
when the user rang up and said that there was smoke coming out of his
Sun Workstation ... but after several phone calls later from his manager
we went down to look at the beast. And sure enough, it was blown.
I doubt if they can cause a fire if they overheat or the fans stop. Maybe
something will melt and smoke but nothing more.
---- Message 7 ----
In the pedastals, there is an array of four fans in the base. It seems
very unlikely that one fan less is going to make much of a difference.
The pedastal power supply has a single fan, that would be trouble.
I've had one of each fail, each time the failure was very noisy
(bad bearing).
The rack has another array of fans in the base of the cardcage,
and the power supply shares these fans.
BTW, even in your computer room, you would be pretty much dead if all
the fans failed on a system. I don't think your risk of fire is really
any greater outside the computer room. The effects of the fire
may be different (do you have halon in the computer room?),
[ Are you kidding? Before, they just had air conditioning. You *really*
don't want to know where they are *now*. In fact, answers on a postcard to
Steve_Kilbane@gec-epl.co.uk.... -Steve ]
but the
probability of a fire starting in the first place really shouldn't
change much.
---- Message 8 ----
None of our old sun3 kit is in an air cond environment and we
never had any probs apart from normal failure (whoops, I should never had said that :-)). Our sun kit includes lots 3/50, a few 3/60 and the odd 3/150 & 3/160.
---- Message 9 ----
I don't know what the Sun recommend policy on cooling machines is,
but for about 4 years we successfully had a Sun 3/160, 3/260, disks,
tape drive and a few other (smaller) Suns in a non-air conditioned Lab.
The Lab doesn't have any windows that open, so the temperature regularly
reached 30C during the summer.
---- Message 10 ----
All those systems have to meet UL aproval (and the European equivalent),
therefore they cannot catch fire simply by overheating.
The power supplies have thermal sensors and will shut down in an overheat
condition.
---- Message 11 ----
I don't see how air conditioning would make much difference if the fans
stop- the thermal conductivity of the case, air inside, etc is low
enough that I doubt that the say 10 degree difference between an air
conditioned room and a normal room would make any difference. (Actually
in the UK is there any difference in temperature?)
---- Message 12 ----
It's fairly unlikely that they'll catch fire, the fans are there to
keep the machine (chips) cool. If the fans stop, the machine overheats
and dies. We have a couple in a minimal air conditioning that have no
internal disk with no trouble. When it was very hot (80 degrees F or more)
we put a fan towards the vents and turned it off when it was too hot
to work (house was 90 degrees).
I kind of doubt that they'd cause anything to burn, but I hear
weird stories.
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:50 CDT