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Medical Grade Isolation Transformers
See also;
AMVECO Medical Grade Isolation Transformers,
ACME HARMONIC MITIGATING TRANSFORMERS &
ACME CONSTANT VOLTAGE REGULATORS & LINE POWER CONDITIONERS TRANSFORMERS,
Medical
Grade Transformers refer to the transformers used in medical
devices as well as hospital, biomedical and patient care equipment.
There are a number of strict safety rules, guidelines and laws governing
the design, construction and the test of these transformers. These
safety rules, guidelines and laws include, but are not limited to:
· The limit of maximum earth leakage current
· The maximum patient leakage current
· The maximum enclosure leakage current
· The maximum patient auxiliary current
· The values of test voltage (high potential voltage test between
windings)
· The minimum creepage distance
· The minimum air clearance
· The maximum temperature rise at load and at over load
One can find these rules and regulations in UL 2601-1, IEC 601-1, CSA
C22.2 No. 601 and EN 60601-1 standards.
The majority of medical grade transformers are isolation transformers.
There are generally two types of isolation, one that relies on Safety
Ground, and one that relies on Double or Reinforced Insulation. A
transformer that relies on safety ground uses a basic isolation between
the primary and the safety shield and shield to secondary. This shield
has to be thick to be able to meet required tests in the safety
standard. If the isolation breaks, the electrical path goes directly to
ground, providing safety. For a transformer that relies on double or
reinforced Insulation there is no "safety" shield, but the insulation as
indicated by the name, is much thicker. It is designed so that all
layers of the insulation can pass the thickness and high potential
voltage tests required by the standard. If one insulation layer breaks,
the next layer will be able to provide the required safety. In both the
design options, the construction design must still meet the required
creepage and clearance requirements. If the transformer includes a
static shield for noise reduction, it is important to note that this
shield does not provide the transformer with Safety Ground but it
working as a functional earth. When the shield is grounded, it
attenuates the common mode noise and can reduce the leakage current from
the primary to the secondary winding (please note that this leakage
reduction is not the same as when measured Primary to Ground).
Normally, without extra mechanical barriers between the primary and
shield and secondary, a transformer with double/reinforced insulation
has lower leakage current than the one with Safety Shield.
A Safety Shield wire should be connected to the Protective Earth
terminal in the equipment while the Static Shield, if included, should
be connected to the Functional Earth terminal.
Power Transformer Sources:
Power Transformer
* Step Up Transformer *
Step Down Transformer *
Electrical
Transformer *
Isolation Transformer *
Toroidal Transformer *
Acme
Transformer * High
Voltage Transformer *
Distribution Transformer *
Transformer
Manufacturer * Three
Phase Transformer * Dry
Type Transformer * 3
Phase Transformer *
Cast
Transformer * Voltage
Transformers *
Variac * Voltage
Stabilizer * Voltage
Regulators
Power Transformer Information:
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Power Transformer Types
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Step Up and Step Down Transformers
to Power transformers to step-up ( raise) or step-down (lower) the
electrical voltage.
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Isolation Transformers
allows signal or power to be taken from one device and fed into
another without electrically connecting the two.
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Toroidal Transformers
are devices that transfer electrical energy from one electric
circuit to another, without changing the frequency, by
electromagnetic induction.
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Custom
Transformers
are designed to meet certain performance specifications and size
requirement that you require. There is a wide range of custom
transformer types.
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Buck Boost Transformers
is a ideal solution for changing line voltage by small amounts.
Often used to buck (lower), or boost (raise) the voltage from 208v
to 240v for lighting applications.
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Pole Mounted Transformers
are mounted to poles for overhead electrical lines. Used in various applications.
Are available in single phase or three phase transformers.
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Medium Voltage Transformers
are used with a medium range of voltages. They come in a full
range from liquid-filled, convention dry type as well as cast coil.
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Pad Mounted Transformers
are a excellent choice for commercial and industrial such as
manufacturing facilities, refineries, office buildings, schools,
hospitals, restaurants, and retail stores. They come in various
sizes and can be used underground as well.
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High
Voltage Transformers
typically these voltage transformers are used in power transmission
applications. High voltage transformers are also used in microwave.
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- ACME Transformers
- With Acme Electric being in business
over 80 years, they have always believed in offering there customers superior service, quality and technical expertise in the
transformer market.
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AMVECO Transformers -
AMVECO designs and manufactures toroids
transformers, current transformers, and auto transformers. Most
AMVECO products are custom designed utilizing their state-of-art proprietary
CAD programs. The AMVECO engineers can quickly generate designs in a
matter of hours, if needed.
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Federal Pacific Transformers -
Federal Pacific is a division of Electro- Mechanical Corporation, a
privately held, American owned company founded in 1958. Federal
pacific offers dry-type transformers from .050 KVA through 10,000
KVA single and three phase, up to 34.5 KV, 150 KV BIL with UL
approval through 15 KV.
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Marcus Transformer - Ever since they opened their doors for business a half a century ago,
they have been a leader in innovative transformer design. As a
family-owned company they are proud of the reputation they have
earned for making quality-built transformers that deliver
exceptional performance and savings.
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Hammond Transformers - Hammond Manufacturing was founded in 1917 in Guelph, Ontario,
Canada. In the last 3 decades it has expanded to the US and the
international markets offering many types of power transformers.
- TEMCo Transformers
- TEMCo Transformer, a family-owned business which has been
manufacturing and distributing electrical products since
1968. They focus on transformers that significantly
reduce power consumption over 30 percent compared to competitive
makes.
- GE Transformers - GE has been a key player in the energy industry for
more than a century. Since the installation of
their first steam turbine in 1901. They have become
number one provider of high-technology power generation
and distribution equipment.
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Jefferson Electric Transformers - Jefferson Electric has
been a pioneer and innovator of magnetic products since 1915.
Jefferson broad line of dry-type transformers are backed by quality
assurance systems so stringent that each and every unit gets
thoroughly tested before it goes out there door.
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More power transformer brands -
Check out more companies by clinking this link.
Power Transformer Types
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Distribution Transformers - Distribution
transformers are generally used in electrical power
distribution and transmission power. This class of transformer has
the highest power, or volt-ampere ratings. and the highest
continuous voltage rating.
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Substation Transformers -
Substation Transformers are large
devices which usually weigh tens of thousands of pounds. They are
filled with tens of thousands of gallons of heat transfer fluid.
Although they are typically 99.8% efficient in the transforming of
electricity from one voltage to another, processing hundreds of Mega
Volts-Amps of electricity force the liberation of hundreds of BTUs
per second.
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Medical Grade Isolation
Transformer -
Medical Grade Transformers generally refer to the transformers
used in medical devices as well as hospital, biomedical and patient
care equipment. There are a number of strict safety rules,
guidelines and laws governing the design, construction and the test
of these transformers.
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Drive Isolation Transformer -
They are used to isolate a drive from a main power line to
prevent the transmission of harmonics that the drives produce back
into the power line. They stop drive harmonics from disrupting
computers and other sensitive equipment.
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Toroidal Transformers -
Toroidal Transformers are more efficient than the cheaper laminated EI types of similar power level. Some of the advantages are smaller
size, lower weight, less mechanical hum, (making them superior in
audio amplifier), low-off-load loss.
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- Step-Up
Transformers - A Step-Up Transformer is one
whose secondary voltage is greater than its primary
voltage. This kind of transformer "steps up" the
voltage applied to it. -
- Step-Down
Transformers - A Step-Down Transformer is
designed to reduce voltage from primary to
secondary. They can range from sizes from .05 KVA
to 500 KVA
- Isolation
Transformers - An Isolation Transformer is a
device that transfers energy from the alternating
current (AC) supply to an electrical or electronic
load. It isolates the windings to prevent
transmitting certain types of harmonics.
- Buck
Boost Transformers - Buck Boost Transformers
make small adjustments to the incoming voltage. They
are often used to change voltage from 208v to 240v
for lighting applications. Major advantages of Buck
boost transformers include; low cost, compact size
and light weight.
- High
Voltage Transformer - There are many
different types of voltage transformers. A High
Voltage Transformer operates with high voltages.
Typically, these voltage transformers are used in
power transmission applications, where voltages are
high enough to present a safety hazard.
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Medium Voltage Transformers - A Medium
Voltage Transformer can be connected directly to a
primary distribution circuit and generally has the
most load diversity. These voltage transformers have
installation practices that are generally in
accordance with application recommendations from the
Institute of Electrical and Electronic Engineers
(IEEE).
- Low
Voltage Transformers - A Low Voltage
Transformer is an electrical device that transforms
120 volts (line voltage) into 12 volts or 24 volts
(low voltage). Some uses for low voltage transformer
are in landscaping lighting.
- Single
Phase Transformers - In electrical
engineering, single-phase electric power refers to
the distribution of electric power using a system in
which all the voltages of the supply vary in unison.
Single-phase distribution is used when loads are
mostly lighting and heating, with few large electric
motors.
- Three
Phase Transformers - Three Phase
Transformers must have 3 coils or windings connected
in the proper sequence in order to match the
incoming power and therefore transform the power
company voltage to the level of voltage needed while
maintaining the proper phasing or polarity.
- Custom
Transformers - Custom Transformers are
designed for a certain performance specifications
and size requirements. The company works with your
engineering specification.
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Industrial Control Transformers - Industrial
Control Transformers are used to convert the
available supply voltage to the required voltage to
supply industrial control circuits and motor control
loads.
- Pad
Mounted Transformers - Pad Mounted
Transformers are usually single phase, or three
phase, and used where safety is a main concern.
Typical applications; restaurant, commercial
building, shopping mall, institutional.
- Pole
Mounted Transformers - Pole Mounted
Transformers are used for distribution in areas with
overhead primary lines. Outside a typical house one
can see one of these devices mounted on the top of
an electrical pole.
- Oil
Filled Transformers - Oil Filled
Transformers are transformers that use insulating
oil as insulating materials. The oil helps cool the
transformer. Because it also provides part of the
electrical insulation between internal live parts,
transformer oil must remain stable at high
temperatures over an extended period.
- Dry Type
Transformers - Dry-Type Transformers are
available for voltages up through 34.5 kV (although
the most common upper limit is 15) and KVA ratings
up through 10,000 (with 5000 as the usual limit).
Dry-type use air as a coolant, lowering health and
environmentally concerns.
- Auto
Transformers - An Autotransformer is an
electrical transformer with only one winding. The
winding has at least three electrical connection
points called taps. Autotransformers are frequently
used in power applications to interconnect systems
operating at different voltage classes, for example
138 kV to 66 kV for transmission. Another
application is in industry to adapt machinery built
for 480 V supplies to operate on the local 600 V
supply.
- More power
transformer types - Read further about
additional transformer types and their uses.
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Electrical Transformers - Electrical
Transformers are devices used to raise or lower the
voltage of alternating current. For instance, power
is transported over long distance in high voltage
power lines and then transformers lower the voltage
so that the power can be used by a business or
household.
- Isolating
Transformers - An Isolating Transformer is a
transformer, often with symmetrical windings, which
is used to decouple two circuits. An Isolation
transformer allows an AC signal or power to be taken
from one device and fed into another without
electrically connecting the two circuits. Isolation
transformers block transmission of DC signals from
one circuit to the other, but allow AC signals to
pass.
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Transmission Power Lines - A Transmission
Line is the material medium or structure that forms
all or part of a path from one place to another for
directing the transmission of energy, such as
electromagnetic
or acoustic waves as well as electric
power transmission. Components of transmission lines
include wires, coaxial
cables, dielectric slabs, option fibers,
electric power lines, and waveguides.
- Transformer
Voltage - The measure of the amount of force
on a unit charge because of the surrounding charge.
- Transformer
Phase - Most transformer are either single
phase or three phase.
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Transformer Frequency - The transformer
cannot change the frequency of the supply. If the
supply is 60 hertz, the output will also be 60
hertz.
- Transformer
K Factor - Some transformers are now being
offered with a k-factor rating. This measure the
transformer's ability to withstand the heating
effects of non-sinusoidal harmonic currents produced
by much of today's electronic equipment and certain
electrical equipment.
- Primary Voltage
- The coil winding that is directly connected to
the input power.
- Secondary
Voltage - The coil winding supplying the
output voltage.
- Harmonic
Cancellation - Harmonic cancellation is
performed with harmonic canceling transformers also
known as phase-shifting transformers. A harmonic
canceling transformer is a relatively new power
quality product for mitigating harmonic problems in
electrical distribution systems. This type of
transformer has patented built-in electromagnetic
technology designed to remove high neutral current
and the most harmful harmonics from the 3rd through
21st.
- Weatherproof -
Enclosed transformers come with a weatherproof
standard set by NEMA.
- Epoxy
Encapsulated - A process in which a
transformer or one of its components is completely
sealed with epoxy or a similar material. This
process is normally preferred when a unit might
encounter harsh environmental conditions.
- More power
transformer terms - Such as inductor, ground
fault, core saturation, current transformer, faraday
shield, etc.
Related Transformer Products
- Voltage
Regulators - A Voltage Regulator is an
electrical regulator designed to automatically
maintain a constant voltage level. It may use an
electromechanical mechanism, or passive or active
electronic components. Depending on the design, it
may be used to regulate one or more AC or DC
voltages.
- AC Line Reactor
- AC Line Reactors is a three phase transformer
used in conjunction with AC variable frequency and
DC motor drive. They are a bi-directional protective
filtering device.
- Line
Power Conditioners - Power or Line
Conditioners regulate, filter, and suppress noise in
AC power for sensitive computer and other solid
state equipment.
- DC Power
Supplies - Conversion of one form of
electrical power to another desired form and
voltage. This typically involves converting 120 or
240 volt AC supplied by a utility company to a
well-regulated lower voltage DC for electronic
devices.
- Rotary
Phase Converters - Rotary Phase Converters
are commonly used in home or small commercial or
industrial settings. Rotary phase converters convert
single-phase power into three-phase power. This is a
very cost-effective way to power three-phase
electric motors and other three phase equipment.
- Frequency
Converters - A Frequency Changer or
Frequency Converter is an electronic device that
converts alternating current (AC) of one frequency
to alternating current of another frequency.
- Voltage
Converters - A Voltage Converter changes the
voltage of an electrical power source and is usually
combined with other components to create a power
supply.
- Magnetic
Motor Starters - Magnetic Motor Starters are
essentially heavy duty relays mounted in boxes,
often equipped with heater/thermal overloads matched
to the motor they start.
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Motor Starting Auto Transformers - An Auto
Transformer starter uses an auto transformer to
reduce the voltage applied to a motor during start.
The auto transformer may have a number of output
taps and be set-up to provide a single stage
starter, or a multistage starter.
For an additional resource the
Best of
Industry Web Directory :
Electrical Power Transformer Directory section is
quite useful. |
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