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Description
The SX2120-SEQ is a 120V 20 amp three-bank AC power sequencer incorporating SurgeX
®
power conditioning and surge protection. The surge protection is rated A-1-1, the highest
standard of the Federal Commercial Item Description for Endurance. The two rack-space steel
enclosure is designed to be installed in a 19 inch equipment rack. A total of fourteen 120V
receptacles are provided on the rear panel, two of which are always on, with the remaining
twelve configured as three sequenced banks of four receptacles, labeled A, B and C.
SurgeX ICE™ Inrush Current Elimination circuitry is incorporated into the SX2120-SEQ. This
eliminates problems associated with inrush currents from large loads such as amplifiers. With
SurgeX ICE™ it is not necessary to take inrush currents into account when designing the AC
power for a system, and special time-delay circuit breakers are not required: you only need to
ensure that the steady-state currents of all products plugged into the SX2120-SEQ are within the
20 Amp rating of the product and within the rating of the AC wiring.
The front panel houses a three-line back-lit LCD display which provides status information in
normal use and allows interaction with menu items during programming. Also on the front panel
are two screwdriver-accessible rotary encoders which are used to step through and select from a
menu of items which determine the operation of the unit. The red push button, when pressed,
causes the unit to power up or power down. This button can be disabled if not required. The red
LED above the button indicates the status of the unit. When the red LED is off the unit is fully
powered down; when it is on the unit is fully powered up; when it is flashing the unit is in the
process of powering up or down.
A built-in AC voltmeter indicates the line voltage on the third line of the LCD display. The
internal voltmeter is a peak reading type which was chosen because most electronic equipment
incorporates a power supply that charges mostly during the AC peaks. Monitoring the peak of
the AC provides a more useful indication of the actual voltage available to the electronic
equipment plugged into the SX2120-SEQ.
The SEQ is microprocessor controlled and designed to be versatile and expandable. Two or more
SEQs can be connected together to provide control and power conditioning for larger systems.
The SEQ can also control other SurgeX products with its auxiliary relay contacts to provide for
expandability. All options are set via the front panel and all connections are made at the rear
panel. An optional password of up to six letters can be entered preventing unauthorized access to
set-up information. All set-up information is stored in a non-volatile memory.
A plug-in Phoenix terminal block on the rear panel accommodates the remote control
connections and also the low-voltage outputs. There are three inputs which control sequencing;
one programmable 12V dc output; and one programmable auxiliary relay providing a pair of
normally-open contacts. The inputs can be controlled by an applied DC voltage from 5V to 30V,
by a contact closure, or by different types of switch; the input selection being made during
programming. The inputs and 12V output are designed to withstand incorrect connections
including polarity reversal and shorts.
