KAOS Lab Safety, May 15, 2012; last updated May 23, 2012
Our computer equipment might not be as dangerous as the above looks,
but that doesn't mean you can't get hurt.
Things can and will go wrong.
General Safety Issues For KAOS Labs
All students, faculty, and staff are expected to know and abide by the following rules:
In general, it is expected that everyone will use ordinary care not only to follow
safety guidelines, but also to know and follow University of Kentucky safety
procedures and rules. For example, smoking is not permitted in any KAOS facility.
Ultimately, you are responsible for knowing and using appropriate safety equipment
and procedures. If there is anything unclear, it is your responsibility to seek
clarification. If you see a potential danger that we have not addressed, it is your
responsibility to report it to Professor Dietz.
If you see signs of a developing problem, deal with it if you can but always report it.
Professor Dietz is often in his office, room 203 Marksbury.
The Marksbury main office is also a good place to report issues in Marksbury;
the Electrical and Computer Engineering main office, 453 FPAT, is appropriate
for reporting issues in the facilities in FPAT.
If you do get injured, seek assistance immediately. 911 can save a life -- maybe yours.
Even the charge left in a small capacitor can be enough to cause injury or death;
be careful how you handle electrical wiring and components, even if they are not plugged in.
We also use a lot of extension cords and power strips, and you must respect their ratings;
in particular, many are rated at 15A but are plugged-into 20A circuits, so it is quite
possible to overload them if you don't pay attention.
It is useful to note that power in our labs
comes from multiple circuits, and it is possible that ground on one
circuit differs significantly from ground on another, leading to a
potentially damaging flow of current between grounds. Similarly,
signal grounds are not necessarily the same as chassis grounds.
By far the most common injuries in our lab involve minor cuts from handling
the often sharp, poorly finished, edges of parts of metal PC cases.
Be aware of this and take whatever precautions are appropriate.
Food and drink are allowed in our labs. For cluster supercomputer build parties
and some group meetings, we often supply food. There is even a small
refrigerator and microwave in 108 Marksbury. However, eating generally should
be confined to 108 Marksbury, and mostly done on the conference/work tables --
safely away from any electronics. Anyone eating or drinking is expected to clean-up after
themself. Never leave unlabeled or outdated food/drink in the refrigerator.
Specific Safety Issues For KAOS Machine Rooms
The rooms that house our cluster supercomputers, 672 FPAT and 108A Marksbury,
are intended to be comfortable for cluster supercomputers, not humans.
There are various issues to be aware of:
Machine rooms are loud. Short exposure is probably harmless, but do not
work for extended periods in a loud machine room without hearing protection.
Noise levels in 672 FPAT are usually tolerable, but
earplugs are available in 108 Marksbury for use in 108A Marksbury.
Noise levels could fluctuate depending on what systems are there and running --
and even how stressed they are (fan speeds are controlled based on loading).
Thus, it is ultimately your responsibility to determine and apply appropriate
hearing safeguards based on the noise levels you observe.
On May 23, 2012 simple measurements were made of the sound levels in the 108A
Marksbury machine room and the nearest section of room 108 where KAOS students
work. The OSHA Occupational Noise Exposure guidelines require "a continuing,
effective hearing conservation program ... whenever employee noise exposures
equal or exceed an 8-hour time-weighted average sound level (TWA) of 85
decibels measured on the A scale (slow response) or, equivalently, a dose of
fifty percent." Exposure to 80dBA or greater is counted in computing the
average dose. Sound levels in 108 are of little concern, as they peaked around
56dBA. Although 108A is rarely occupied for even an hour per day, it averaged
around 80dBA with the loudest area (near the corner farthest from the door)
peaking around 85dBA. The primary sound source seems to be the floor vents; in
fact, the hot aisle was at least 5dBA quieter despite the multitude of little
fans blowing hot air from inside PC cases. Thus, it appears that noise levels
in 108A are unlikely to be significantly increased by the computer equipment
operating in the room.
Racks of equipment are heavy. Be careful how you push the racks around
and do not climb or lean on them.
Cluster supercomputers have many cables interconnecting components,
routing power, etc. Be very aware of what cables you're touching and
be careful not to trip or become entangled.
Be aware of air conditioning:
- 108A Marksbury
- The floor is raised above a chamber that serves as a duct to provide
cooling to the room; the air return is in the top of the unit in the back
of the room. Beware loose or uneven tiles. Also be aware that air will
usually still flow even when it is not being cooled, so notify others if
the floor vent tiles are not blowing cold air. There is an emergency
shutdown script for powering-down the clusters.
- 672 FPAT
- The air conditioner and return is in the rear left corner, with cold
air dumping from the ducts that run along the ceiling to the left. This
unit can deliver 5 Tons of cooling... in addition, the building's ducts
can deliver up to about 7 Tons of heating or cooling. The thermostat by
the door controls the building system, and it should never
be set to provide heat because that will cause the 5 Ton unit to burn-out
in an attempt to compensate. The thermostat for the 5 Ton unit is next to
it. If the room becomes warm, notify others.
In case of a fire, be aware that machine rooms like 108A Marksbury or
672 FPAT generally only have one exit. Don't let a fire get between you
and the exit. Also be aware that our machine rooms have water sprinkler
systems for fire control, which doesn't suck the oxygen out of the air
like some systems, but the combination of literally tons of electrical
equipment and water does not make a safe environment. Get yourself (and
anyone else you can) out and get help.
The big red button near the door in
108A Marksbury is supposed to kill the power to everything in the room.
Don't press it unless absolutely necessary, but if somebody is being
electrocuted or there's a fire that could trigger the sprinklers,
hit that button immediately.
The only thing set in stone is our name.