Emerson ASCO 300 Group 1 Brochures and Data Sheets

Power Switching & Controls
for Business-Critical Continuity

ASCO Ser i es 300
Power Transfer Switches
for Power Outage Protection

24-hour protection no matter
when trouble strikes

Where would you be

without a constant flow of
electrical power? We often
take for granted that power
will always be around when
we need it. In reality, power
failures are very common.
And when the power goes
out, your business suffers.
Power failures are unpredict­able. They can occur at any
time and for any number of
reasons—a bolt of lightning,
a power surge, a blackout,
an accident or even equip­ment failure. They come
without warning and often
at the most inconvenient
times.
It’s for this reason that
many businesses and other
entities have invested in
emergency power backup
systems. Typically, the sys­tem consists of an engine

generator and an automatic
transfer switch (ATS) which
transfers the load from the
utility to the generator.
An ATS with built-in
control logic monitors your
normal power supply and
senses any interruptions.
When the utility power fails,
the ATS automatically starts
the engine and transfers the
load after the generator has
reached proper voltage and
frequency. This happens in
a matter of seconds after
the power failure occurs.
When the utility power has
been restored, the ATS will
automatically switch the load
back, and after a time delay,
it will shut down the engine.
With an Automatic Transfer
Switch, you are protected
24 hours a day, seven days a
week.

2

Typical Applications

Telecom

In the telecommunications
industry, providing a high level
of service and dependability is
crucial. Lost power means an
interruption in service for your
customers and lost business
for your company. For instance,
with cell sites scattered across a
wide geographical region and in
many remote areas, the chances
of an interruption in power are
increased, making Automatic
Transfer Switches a valuable
resource at each location. To
maintain dependable service,
each cell site must be monitored
24 hours a day. This can be
very difficult without some
type of remote monitoring and
testing capability. The
Transfer Switch, combined with
ASCO’s monitoring and control
management system, is a cost­effective, packaged solution
which can help meet both of
these challenging objectives
without a major investment
at each cell site. With ASCO’s
connectivity solutions you can
remotely monitor and control
numerous sites from around
the corner or around the world.

SerieS 300

Agriculture

Maintaining electrical power
is vital to an agriculture opera­tion. If the flow of power is
interrupted, your operation
could be at risk unless the
backup generator is quickly
activated. A prolonged power
outage can affect numerous
aspects of the operation, from
housing and feeding livestock
to processing and produc­ing the end product. With
an ASCO
Switch, power will automatical­ly be transferred over to your
backup generator, eliminating
the need to manually switch
from utility to generator. When
power is restored, the ASCO
SerieS 300 Transfer Switch will,
after an adjustable time delay
to allow for utility stabilization,
automatically switch the load
back to the utility service.

SerieS 300 Transfer

Commercial /Retail,
Light Industrial

The retail industry is very com­petitive. An electrical power
failure can have a dramatic
impact on a retailer’s bottom
line. If power is interrupted
during peak shopping times,
the effect could be extremely
damaging to present and
future business. A power inter­ruption will not only suspend
shopping, it can also create
safety problems, result in lost
transaction data, lost account
information and damage to
data collection equipment. In
addition, retailers who rely on
controlled climates to protect
valuable inventory could suffer
even greater losses, especially
if the power failure occurs at
a time when no one is avail­able to rectify the situation. To
avoid any of these power out­age problems, simply install a
backup generator with an ASCO

SerieS 300 Transfer Switch and

power outage concerns will be
a thing of the past.

Municipal

The ASCO SerieS 300 Transfer
Switch can be a critical com­ponent of a municipal gov­ernment’s emergency power
backup system. Residents of
townships, cities and counties
rely on police, fire, ambulance/
first aid and other critical
public sector services. An inter­ruption in power would affect
the ability of emergency ser­vices to effectively respond to
the needs of the community.
When time is a critical factor,
such as when responding to a
fire alarm or an emergency call,
an ASCO
Switch can be a lifesaver,
switching power to the backup
generator. While not all munic­ipal services are a matter of
life and death, they are always
expected to be there.

SerieS 300 Transfer

3

series 300 Power Transfer Switches

Maximum Reliability & Excellent Value

With a SerieS 300 Transfer Switch, you get a product backed by
ASCO Power Technologies, the industry leader responsible for virtually every
major technological advance in the Transfer Switch industry.

The ASCO
transfer critical loads in the event of a power outage. Each and every
standard component was designed
by ASCO engineers for this purpose.

The rugged construction and proven performance of the ASCO
SerieS 300 assure the user of many years of complete reliability.
The
placed on the switch when starting or restarting stalled motors and
switching high inrush loads.

ASCO’s
and maintain. All parts are accessible from the front so switch contacts can
be easily inspected.

SerieS 300 was designed for one purpose–to automatically

SerieS 300 is even designed to handle the extraordinary demands

SerieS 300 modular, compact design makes it easy to install, inspect

Features

The SerieS 300 is listed to UL 1008 standard for Transfer Switch

Equipment and CSA standard C22.2 for automatic transfer switches.
Meets NFPA 110 for Emergency and Standby Power Systems
and the National Electrical Code (NEC) Articles 700, 701 and 702.
30 through 3000 amps in a compact design.

Available to 600 VAC, single or three phase.

True double-throw operation: The single solenoid design is inherently
inter-locked and prevents contacts from stopping between sources
or from being in contact with both sources at the same time.

UL Listed Withstand & Close-On Ratings

Available Symmetrical Amperes RMS

Switch Ratings

Amps

30 100,000 480v/60Hz 10,000

70 - 200 200,000 480v/60Hz 22,000
230 100,000 480v/60Hz 22,000
260, 400 200,000 480v/60Hz 42,000
600 200,000
600 200,000
600 200,000
800,1000,1200
1600, 2000 200,000 600v/60Hz 85,000
2600, 3000 200,000

When Used

With Current

Limiting Fuses

200,000 600v/60Hz 65,000

Maximum

Voltage

600v/60Hz 42,000
480v/60Hz 50,000
240v/60Hz 65,000

600v/60Hz 100,000

When Used

With Specific

Circuit Breakers

Fig. 1: ASCO Power Transfer Switch rated

200 amperes shown in Type 3R enclosure

There’s no danger of the SerieS 300 ATS

transferring loads to a dead source because
the unique ASCO single-solenoid operator
derives power to operate from the source to
which the load is being transferred.

Easy-to-read flush-mounted control and

display

panel provides LED indicators
for switch position and source availability.
It also includes test and time-delay bypass
switches as standard features.
Standard engine exerciser for weekly
automatic testing of engine generator set
with or without load.

Adjustable time-delay feature prevents switch

from being activated due to momentary
utility power outages and generator dips.

Supplied with solid neutral termination.

Optional switched neutral pole available.

Accessory kits available.
Available for immediate delivery.
Now available for service entrance

applications. Contact ASCO for assistance.

Notes: 1. Current – limiting fuse should be Class J type through 400 amps:

2. Refer to publication 1128 for specific manufacturer ’s breakers

use Class L type above 400 - amp fuse rating

4

series 300 Power Transfer Switches

Designed to Fit Anywhere

The ASCO SerieS 300 product line represents the most compact
design of automatic power transfer switches in the industry. With
space in electrical closets being at a premium, the use of wall or
floor-mounted ASCO Power Transfer Switches assures designers
optimum utilization of space.

All transfer switches through 2000 amps are designed to be
completely front accessible. This permits the enclosures to be
installed flush to the wall and still allows installation of all power
cabling and connections from the front of the switch. Cable entrance
plates are also standard on the 1600 and 2000 amp units to install
optional side-mounted pull boxes for additional cable bending space.

Fig. 2: ASCO Power Transfer Switch
rated 200 amperes

Fig. 3: ASCO Power Transfer Switch
rated 400 amperes

Fig. 6: ASCO Power Transfer Switch

rated 2000 amperes shown in Type 3R enclosure

Fig. 4: ASCO Power Transfer Switch
rated 600 Amperes

Fig. 5: ASCO Power Transfer Switch
rated 1000 amperes

Fig. 7: ASCO Power Transfer Switch
rated 3000 amperes

5

series 300 Microprocessor Controller

The ASCO Microprocessor Controller is used with all sizes of Power Transfer Switches. It represents the most reliable
microprocessor controller in the industry and includes, as standard, all of the voltage, frequency, control, timing and
connectivity functions required for most emergency and standby power applications.

Voltage & Frequency Sensing

Adjustable three-phase, close-differential voltage sensing

on normal source.

Normal source pickup voltage is adjustable to 95% of

nominal; drop-out is adjustable from 70% to 90% of nominal.

Frequency sensing on emergency source. Pickup at 95% and

dropout at 85% of nominal.

Time Delays

Adjustable time delay to override momentary normal

source outages to delay all transfer switch and engine-
starting signals.

Fig. 8: ASCO SerieS 300

Microprocessor Controller

Transfer to emergency time delay

minutes for controlled timing of load transfer to emergency.
Re-transfer to normal time delay
Five-minute unloaded running time delay for emergency

engine generator cool down.

Four-second time delay to ignore momentary voltage and

frequency transients during initial genset loading.

––

Adjustable from 0 to 5

––

Adjustable to 30 minutes.

Fig. 9: Door-Mounted Control & Display Panel

Control and Display Panel

Easy-to-read flush-mounted control and display panel

provides LED indicators for switch position and source avail­ability. It also includes test and time-delay bypass switches.

Standard Selectable Features

Inphase monitor to transfer motor loads, without any

intentional off time, to prevent inrush currents from

exceeding normal starting levels.
Engine exerciser to automatically test backup generator

each week—Includes control switch for testing with or

without load.
Selective load disconnect, double-throw contact to operate

at an adjustable 0 to 20 second adjustable time delay prior

to transfer and reset 0 to 20 seconds after transfer.
60 Hz or 50 Hz selectable switch.
Three-phase/single-phase selectable switch.

Remote Control Features

Terminal provisions for connecting:

Remote test switch.
Remote contact for test or for peak shaving applications.

Circuit will be automatically bypassed if emergency

source fails.

Remote time-delay bypass switch.

6