Duplex Heavy Duty Controllers
General
Class 83
Class 84
CONTROL
PRODUCTS
16
Features
▪ Heavy Duty NEMA Starters
▪ Solid State or Thermal Overload
Relays
▪ Fusible or MCP
▪ Heavy Duty Disconnect Handle
▪ Flexibility with Field Modifications
▪ Alternator Transfer on De-energization
▪ UL Listed for Outdoor Use and
Service Equipment
▪ UL Listed file #E14900 (class 83); file
#E185287 (class 84)
▪ CSA certified file #LR 6535 (class 83
& 84)
NEMA & General
Purpose Control
Application
Duplex pump controls are designed to
perform one or both of two distinct
functions: duplexing and alternation. The
duplexing function provides capacity for
system peaking or above normal demand
without having the full motor capacity
spinning at all times. It also provides
standby capacity for use when one of
the motors or pumps is disabled. The
duplexing function is also referred to as
lead/lag or main/standby. When two
pumps or compressors are controlled by
a duplex controller, they are started in
sequence as necessary to attain preset
values of pressure, flow or liquid level.
16-52
Two field devices such as pressure
switches or float switches provide
electrical signals to the duplex controller.
One remote device is set to initiate the
starting of the lead motor. This motor is
rated to handle normal system demand.
The second motor is usually the same
rating and is referred to as the lag motor.
It is only energized when the system
demand is greater than the capacity of
the lead motor. The lag motor is started
when the second remote device is
signalling for more output than the
lead motor can produce.
The alternation function reverses the lead
and lag mode for the two motors in a
duplex system. Upon alternation the first
motor as described above becomes the
lag motor and the second motor
assumes the lead function. The
alternation is usually programmed to
occur at any time both pumps come to
rest. The alternation function equalizes
wear on the two machines and extends
the life of seals and bearings.
Enclosure Types
Duplex controllers are available in
NEMA 1, 12/3/3R, 4 (painted) and
4/4X (stainless) enclosures.
Enclosures protect personnel from
contact with live parts and depending
upon the construction, protect the
control in varying degrees from physical
damage and harmful atmospheres. All
enclosures are supplied with corrosion
resistant finishes.
Heavy Duty Starters
These Duplex controllers use the same
starters described in the heavy duty
starter section of this catalog.
Siemens Type ETI Circuit Breaker
The ETI circuit breaker is a device
designed specifically for application
in motor circuits. The ETI is a magnetic
only protective device designed to
provide protection against short
circuit current.
The instantaneous-only type ETI circuit
breaker employs adjustable magnetic
trip settings to allow broader application
ranges and a higher degree of motor
short circuit protection.
Siemens Power Distribution & Control, SPEEDFAX™ 2007-2008 Product Catalog
Features
Two control transformers may be
provided for low voltage control to
safeguard personnel from high voltage.
One transformer is required for each
starter to provide independent control
circuits.
A Hand-Off-Auto selector switch for each
starter may be mounted in the enclosure
door or furnished separately for remote
control. Test push buttons or pilot lights
may also be installed on the enclosure.
Solid-state or Ambient Compensated
Bimetal Overload Relays are supplied as
standard.
Heavy Duty Disconnect Switches
The disconnect switch that goes the
distance in durability, performance and
reliability has the following advantages:
▪ Visible blades for the highest level
of safety
▪ Double break switching action to
reduce arcing, increase lifetime and
eliminate the “electric hinge”
▪ More rugged positive action switch
▪ Oversized lugs are standard
▪ Line side shield to help guard
personnel from contact with live parts
▪ Higher horsepower rating for
design E high efficiency motors
▪ UL listed for IIsco, Burndy and T&B
crimp type lugs
▪ The 200A switch accepts up to 300
MCM versus 250 MCM wire size
Its rugged construction - with a high
fault withstand rating of 100kA at 600
VAC when fused with class R rated
fuses - meets the most stringent
industry standards set forth by the
automotive, petro-chemical, and pulp
and paper industries. UL recognized and
CSA certified, our disconnect switches
are available either non-fusible or fusible
with class R and class J fuse clips.