Surge Protectors-Power Strips-Safety Item
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-------- Original Message --------
Subject: [RL] Surge Protectors-Power Strips-Safety Item
Date: Thu, 20 Feb 2003 10:21:10 -0800
From: "Erwin Hayer"
To: riolinda@vrx.net
RL/E Net
I received the following safety message on Surge Protectors and Power Strips.
I have extracted the text and will send the photos to Jay.
Erwin
If there is one
pervasive adverse safety hazard , it involves the improper use of surge protectors
and/or power strips. In almost every unit we inspect, surge protectors
and extension cords are being seriously abused. The below information
on surge protectors and the accompanying photographs should be widely disseminated
to all. Surge protectors are proliferating. THEY CAN BE EXTREMELY HAZARDOUS
when used improperly --
A few tips: (For office and home)
- NEVER "daisy chain" surge protectors. (i.e., Hook them together
"in series," where one surge protector is plugged into another to either
increase the number of available outlets or extend their reach.)
- Do not use for high amperage, high draw appliances. (i.e., space
heaters, coffee pots, refrigerators, air conditioners, etc.)
- FREQUENTLY inspect the surge protectors for heat build-up, signs of heat damage, or mechanical damage.
- If you find yourself tempted to overload surge protectors or hook them
together, consider altering the lay-out of your area or moving the appliance
where it can be plugged directly into a wall outlet.
We have previously had fires as a direct result of the misuse of surge protectors/power
strips, and we will have more fires if people continue to abuse them.
An employee arrived at the Greensport Yard in Houston this morning to find
the field office full of smoke. Investigation led him to a melted down surge
protector (see attached photos).
An office-by-office search revealed another surge protector, of the same
brand and model as above, that was starting to melt down (see attached photos).
IT WAS READY TO BLOW!
The manufacturer, Newpoint, was contacted to see if similar incidents have
occurred with this product. Newpoint stated that the surge protector had
absorbed all of the energy it was capable of absorbing and melted down as
a result. The surge protectors involved were not on a recall list.
IMPORTANT INFORMATION ABOUT SURGE PROTECTORS
Most modern businesses and homes are supplied with 220-volt power systems.
Heavy draw appliances such as air conditioners, dryers, and electric stoves
operate on 220-volts and are not protected by surge protectors. Other appliances
operate on 110-volts. These include computers, microwaves, stereo equipment
and TV sets. These items are often used with surge protectors. The normal
voltage flow will range from 110-117 volts. Surge Protectors are designed
to trap the voltage that exceeds those limits. Excessive voltage occurs due
to power spikes.
When these spikes occur for a sufficient duration, this activates the trapping
device, a Metal Oxide Varistor MOV), located in the surge protector. The
MOV is the heart of surge suppressors. The role of the MOV is to divert surge
current. However, MOVs wear out with use. As more surges are diverted, the
MOVs life span shortens, and failure becomes imminent. There is no forewarning
or visual indications given - just failure. And while failing, they can reach
very high temperatures, and actually start fires.
Most surge protectors will continue to function as a power strip, even though
the surge trap mechanism may have been destroyed by the power spike. This
presents two possible dangers: 1) If another power surge should occur, it
can damage the equipment or appliances that are plugged into this surge protector,
and 2) If sufficient voltage passes through the surge protector due to a
second power spike, a resistant short may have been formed, allowing heating
to occur and a fire to ignite.
When buying this equipment, look for a surge protector with an indicator
light that tells you if the protection components are functioning. All MOVs
will burn out after repeated power surges. Without an indicator light, you
have no way of knowing if your protector is still functioning properly. Unfortunately
due to manufacturing differences, the light may be "on" or "off" during proper
operation. It is important to review the operating instructions provided
with the surge protector.
Every year, thousands of fires result from surge protectors, power strips
and electrical cords. Listed below are some suggestions to help prevent a
possible fire from igniting.
- USE ONLY SURGE PROTECTORS OR POWER STRIPS THAT HAVE AN INTERNAL CIRCUIT
BREAKER. These units will trip the breaker if the power strip is over loaded
or shorted to prevent overheating and fire.
- Any surge protector or power strip that has frayed wires, or has a unit that is not working properly, replace them immediately.
- Surge protectors, power strips, or extension cords are not a substitute for permanent wiring.
- If at any time the surge protector or power strip is hot to the touch
remove and replace the unit. The electrical load for this strip should be
evaluated for overloading.
- Do not plug a surge protector or power strip into an existing surge
protector or power strip. This practice is called "daisy chaining" or "piggy
backing" and can lead to serious problems.
- The Underwriters Laboratory (UL) label must never be removed from the
unit. On the underside of the casing, there should be the manufacturer's
name and the name of the testing lab where the unit was tested.
- Do not locate a surge protector or power strip in any area where the
unit would be covered with carpet, furniture, or any other item that will
limit or prevent air circulation.
- Do not locate a surge protector in a moist environment.
All surge protectors or power strips need to be UL approved. Be sure that
the product is listed as a TRANSIENT VOLTAGE SURGE SUPPRESSOR. This means
that it meets the criteria for UL 1449, UL's minimum performance standard
for surge suppressors. There are a lot of power strips listed by UL that
have no surge protection components at all. They are listed only for their
performance as extension cords. On a UL listed surge protectors, you will
find a couple of ratings. Look for:
* Clamping voltage. This tells you what
voltage will cause the MOVs to conduct electricity to the ground line. A
lower clamping voltage indicates better protection. There are three levels
of protection in the UL rating -- 330 V, 400 V and 500 V. Generally, a clamping
voltage more than 400V is too high.
* Energy absorption/dissipation. This
rating, given in joules, tells you how much energy the surge protector can
absorb before it fails. A higher number indicates greater protection. Look
for a protector that is at least rated at 200 to 400 joules. For better protection,
look for a rating of 600 joules or more.
* Response time. Surge protectors don't
kick in immediately; there is a very slight delay as they respond to the
power surge. A longer response time tells you that your computer (or other
equipment) will be exposed to the surge for a greater amount of time. Look
for a surge protector that responds in less than one nanosecond.
Visually inspect all surge protectors or power strips on a regular basis
to ensure that they are not damaged or showing signs of wear or damage. During
the visual inspection, ensure that the plug is fully engaged in their respective
outlets. The surge protector or power strips should always have either a
polarized plug with one of the blades being larger then the other one or
a three-prong grounded plug. Never use a three to two prong adapter to power
the unit. Surge protectors or power strips should have a cord of no more
than 6 feet in length. When the surge protector or plug strip is not in use,
unplug the cord from the power source.
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