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It Pays, Not Costs, To Specify Better Protection
Cooling tower protection will not improve unless
owners of cooling towers, new and old, specify a better solution
than mechanical vibration switches with their baggage of
legacy issues such as: "Run to failure" or claims of "Prevent further damage". It's
up to the cooling tower owners/operators to specify the better protection that is available and cost effective.
We know you want a safe operation.
Your underwriters require it. You pay for it. It
shows everywhere in your plant. Everywhere except possibly
on your cooling towers if you haven't upgraded your cooling
tower protection. It takes surprisingly little effort and
money to raise the bar.
We have your solution:
TEZZCO's Liberator & IMI Vibration
Switches: more
than cooling tower protection- it's cooling tower reliability
and uptime:
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IMI Vibration Switches: Installed for protection
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TEZZCO's Liberator: Small lightweight low cost vibration
data collection
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Outstanding & knowledgeable technical support before and
after the sale
With mechanical shock & vibration switches, you are
protected to some degree by sensing the initial shock of severe
component failure. But that's only if the switch is set right,
mounted correctly and maintained properly: few are.
They are, after all, only a simple lever arm, pivot point,
spring, magnets, and a limit switch. In the vibration
instrumentation business, they are called
"earthquake switches" for good reason. We often hear,
they
are better than nothing at all but that is not a very high standard
for cooling tower protection or the people who work around them.
The model 685B vibration switch does not require a machine failure to
trigger a shutdown or give disaster confirmation. A better goal is to prevent the initial failure and the severe consequences
that even a single incident may bring on.
There is a good deal of mis-information
involved in the use of mechanical vibration switches on cooling
towers. We will do our best to support your support team:
cooling tower OEMs, consultants, E & C firms, service companies, and vibration
analysts. But it's up to the owner/operators of
cooling towers to understand the risk and accept the facts
about mechanical vibration switches: the odds are
stacked against you. It will take a budget of
relatively few dollars per cooling tower to make a big
difference in real cooling tower protection.
Six Good Questions Worth Answering Up Front
1. Why is it we see mechanical vibration switches
mostly on reciprocating machines that bang around and cooling towers but on very few other
rotating equipment?
Acceleration is all that is sensed by
mechanical vibration switches. Good for the
"bangers". But velocity or displacement are used in the great preponderance of
rotating equipment in the world: estimated 90++%;
except for cooling
towers.
2. Why measure the vibration of rotating
equipment at low speed in acceleration?
It would be appropriate for
high RPM machines, very high rpm: with frequencies over 60,000
cpm, but certainly not the 0 to 3600 rpm
range advertised by mechanical switch manufacturers.
That range just happens to be in your range of speeds but does
not agree with the teaching manuals for vibration analysts.
3. If a switch measures in acceleration,
and that is best for high speeds, why limit that switch for operation to
3600 rpm?
Maybe it is limited by
the natural frequency of the mechanism. All devices have
natural frequencies. Vibration switches should not have
natural frequencies in the range of frequencies generated by the
machine they are on. Accelerometers and electronic
switches will have by design very high natural frequencies.
Components of a mechanical vibration switch are likely to have a very low
natural frequency by comparison, perhaps nearer low multiples of
running speed. The IMI vibration switch is designed for monitoring radial vibration on your cooling
towers at running speeds and harmonics needed for analysis.
4. Is your mechanical "vibration" switch
mounted somewhere on the tower structure, not on the rotating
equipment?
Vibration
sensors (not shock switches), if installed on only one location
on your cooling tower, are best installed on
the inboard bearing of the gearbox. Likely, your
mechanical vibration switch is too big and difficult to mount
and service to be on the gearbox. It wouldn't help much
anyway. The
IMI vibration switch is very close
in size to an accelerometer, mounts like an accelerometer, and
its hermetic sealed stainless steel body will take the abusive
environment that your gearbox runs in day in, day out.
Accelerometers have given good service for
many years when mounted and cabled properly in this location.
5. Do you really want to wait for the
SHOCK of your fan, gearbox or motor coming apart before acting?
Every where else in your
plant, machines are not instrumented like your cooling towers
are; even machines of much less size, cost, or importance.
6. What is the cost difference between
the IMI vibration
switch & mechanical vibration switches?
In
budgetary terms, the
IMI vibration switch is
affordable. Some mechanical vibration switches can cost $400 to $600 and up
depending on the make & model. That's about the price of
the 685B. Besides, the 685B works on your cooling tower;
the mechanical "shock" switch does not.
A Vibration Switch Designed For Better Cooling
Tower Protection
The
IMI vibration switch is worlds above
mechanical vibration switches for protecting cooling towers from
vibration levels that are harmful to the equipment &
can be unsafe to personnel.
TEZZCO's field services and experience complement
the IMI vibration switch. We make it easy to buy, install
and own. Options are narrowed down to
best solutions for you and your cooling tower needs. If
for any reason, your requirements are significantly different,
we can supply product and services for your specific needs.
For Customer Service & Technical Information:
call
(716) 652-5440
e-mail info@tezzco.com
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