Specifications

February 2007
16-58
For more information visit: www.eaton.com CA08101001E
Transfer Switches
16
Transfer Switch Equipment
Magnum Closed Transition Soft Load Transfer Switch with ATC 5000 Controller
Magnum Closed Transition
Soft Load Transfer Switches
with ATC 5000 Controller
Magnum Closed Transition Soft Load Transfer
Switch with ATC 5000 Controller
Product Description
General Information
Electrical power generation located at
or near the point of it’s consumption,
commonly referred to as Distributed
Generation, has seen tremendous
growth recently due to factors such
as limited utility grid generation and
transmission capacity combined with
the onset of utility deregulation. Strong
economic incentives now exist for
many users to consider on-site self
generation for both improved power
reliability and energy cost reduction.
Additionally, these opportunities have
spurred the development of new and
unique types of generating and switch-
ing technologies.
Eaton Closed Transition Soft Load
Automatic Transfer Switches are just
such a technology. Closed transition
soft load transfer switches are an ideal
solution for power availability, energy
management, and generator-set exer-
cising applications. Unlike traditional
open transition switches that provide
a break-before-make operation, the
closed transition soft load switch
allows two power sources, usually
the utility and a generator set, to be
paralleled indefinitely. This permits the
load, inductive or resistive, to be grad-
ually and seamlessly transferred from
one source to another. All of this is
accomplished through the make-before-
break operation of the switch with no
power interruption to the load.
Eaton Closes Transition Soft Load
Switch utilizes an integrated micropro-
cessor based power controller to make
active paralleling of two power sources
possible. It manages the speed governor
and voltage regulator of the generator
set to bring the two sources into syn-
chronization. This approach allows the
transfer switch to be applied in soft
load transfer applications. In addition,
it can also be used as a peak shaving
switch helping customers to reduce
their peak demand charges by paralleling
the generator set with the utility source
during times of high electrical demand.
Standard fixed drawout or drawout
bypass isolation configurations are
available with or without an integral
service entrance rating. If a switch with
a service entrance rating is used as
service entrance equipment, the need
for separate service disconnects and
overcurrent protective devices is
eliminated.
Eaton Closed Transition Soft Load
Automatic Transfer Switches are avail-
able for 800 through 3200 ampere, up
to 600 Vac, 50 or 60 Hz applications
worldwide. They are offered in both
indoor (NEMA 1) and outdoor (NEMA
3R) free standing enclosures utilizing
drawout or fixed insulated case Magnum
DS switching devices. The Magnum DS
switching device is a 100% rated device
with a 100 kA interrupting capability at
600 Vac.
Application Description
Power reliability and power costs are
two issues of strategic importance in
almost all industry segments. Busi-
nesses have critical processes that
cannot tolerate a shut down, while an
extended failure in many cases could
cause unrecoverable losses. In addi-
tion, significant changes in the utility
industry have created on-site genera-
tion opportunities for customers to
address their power reliability and
energy cost concerns. This type of
on-site power generation at or near
the point of consumption is known as
distributed generation. Market studies
estimate that over 40% of generation
capacity added in the United States
alone over the next 10 years will be
distributed. A key enabler of these
on-site generation systems and reli-
able power in general is often a closed
transition soft load transfer switch.
Typical applications for Eaton Closed
Transition Soft Load Automatic Transfer
Switches include industrial processes,
data centers and critical care facilities.
Actually, any location with critical loads
where the absence of power could
result in lost revenue, production time,
or personal injury should make this
equipment a prime consideration.
Consider several specific applications:
■ A facility with emergency or critical
power systems wanting to test their
generator sets without a power
interruption.
■ Any industrial, institutional, or com-
mercial business seeking ways to
lower energy costs by reducing
demand charges, which can repre-
sent over 50% of an electrical bill.
■ Energy Service Companies inter-
ested in offering performance based
solutions to their customer base.
■ Electrical power providers inter-
ested in offering power reliability
solutions to their customer base in
return for long term electrical con-
tracts.
The Eaton Closed Transition Soft Load
Automatic Transfer Switch can be
applied in new installations or as a
retrofit to replace an existing open
transition transfer switch. A number of
application issues should be reviewed.
First, since most generator sets run on
diesel fuel, there are exhaust emission
concerns to consider. In some markets,
the Environmental Protection Agency
(EPA) limits the number of hours
annually that a generator set can be
operated. Methods to deal with such
restrictions, should they present a
problem, are the use of natural gas or
dual fuel (natural gas/diesel mixture)
types of generator sets. A second
issue relates to electrical utility inter-
connection standards. Many utility
companies require multiple levels of
protective relaying when a user wishes
to parallel to the utility grid. The cost
of meeting some of these specifica-
tions can be high. These issues should
be discussed when peak shaving is
being considered.
Features, Benefits
and Functions
Sequence of Operations
Automatic Mode Operation — Transfer
Switch Loss of Normal Power
The system will continuously monitor
the condition of the normal power
supply. When the voltage or frequency
of the normal source is sensed outside
the user adjustable set points, and
after an adjustable time delay to over-
ride momentary dips and/or outages, a
contact shall close to initiate a starting
of the emergency or stand-by source.
Transfer to the alternate source shall
take place upon attainment of adjust-
able pick-up voltage and frequency of
the alternate source.