105

Automatic Timing & Controls

800.727.5646

atcdiversified.com

OPERATION

The Shawnee 355 operates on a digital logic circuit with three main

elements: a clock which uses utility line frequency of 50 or 60 Hz

as its time base; a read-only-memory (ROM) whose output is set

by the timer's digital setting number wheels; and a comparator that

continuously examines the outputs of the clock and ROM.

When power is applied (start signal on), two things happen

simultaneously; the instantaneous DPDT relay is energized

transferring both sets of contact, and the clock circuit begins to

count each cycle of the utility line frequency. Translating this count

into hundredths of a second, the clock accumulates it and feeds it

continuously to the comparator. When clock output exactly equals the

output of the ROM, the comparator causes the 355C to time out.

At this point, (1) the DPDT delay relay is energized, immediately

transferring both sets of contacts and (2) the clock turns itself off

automatically. Since the clock stops counting even if the start signal

remains on, it is not necessary to tie up one of the 355C's delayed

contacts to do this job.

To reset the Shawnee 355, power must be removed from terminal 1

(L1) for 75 milliseconds or more. The 355 operates in the On-Delay

mode only, always resetting whenever there is a power outage and

starting a new cycle when power is restored.

CYCLE PROGRESS INDICATION: When the timer is in the reset

condition, the LED display is blank. During the timing cycle, the

display counts up from zero, thus always indicating the amount of

time that has elapsed since the start of cycle. At time-out, the display

shows total elapsed time and exactly equals the numbers on the

digital setting wheels.

SPECIFICATIONS

RANGES

0.01 - 99.99 SEC

0.01 - 99.99 MIN

0.1 - 999.9 SEC

0.1 - 999.9 MIN

Four field-convertible ranges

TIMING

Single Cycle

interval or delay

MODES

Repeat Cycle

pulse (fixed at approx.

50 mSEC)

CYCLE

4 digit, 0.3 inch, high intensity, blue display

PROGRESS

INDICATOR

REPEAT

±0.01 SEC on all ranges

ACCURACY

RESET TIME

75 milliseconds

MINIMUM

99.99 SEC of MIN ranges: 0.01 SEC or MIN,

SETTING

respectively

999.9 SEC or MIN ranges: 0.1 SEC or MIN,

respectively

LOAD

Number

two, one instantaneous and

RELAYS

one delayed; both plug-in DPDT

Operate Time 20 mSEC, max.

Release Time instantaneous — 20 mSEC,

max. delayed — 75 mSEC, max.

Contact Rating 5A @ 120 VAC Resistive,

5A, 30 VDC Resistive

Life

100 million operations (no load)

TEMPERATURE

32° to 140°F (0 to 60°C)

RATING

POWER

120V

95-132V at 50 or 60 Hz

REQUIREMENTS

inrush — 0.2 A

running — 0.04 A

240V

190-264V AT 50 OR 60 Hz

inrush — 0.1 A

running — 0.02 A

Clock Input

Voltage

95-132V rms (120V Model)

190-264V rms (240V Model)

Current

20 mA max.

Frequency 0 to 1000 Hz (sinusoidal)

TERMINALS

16 screw terminals accessible at rear; integral

wiring diagram on housing

HOUSING

Plug-in design; completely gasketed, dust-tight

when panel-mounted

MOUNTING

Standard Hardware is provided to mount

ACCESSORIES

timer so that it is dust-tight from

See Accessory

front of panel

section of

Optional Surface mounting without and with

catalog

front-facing terminals)

WEIGHT

NET: 1 lb., 7 oz. SHIPPING: 2 lbs

Switching Sequence: Assumes a

sustained closed start signal

(i.e. longer than the setting on

the digital display.)

RELAY

CONTACTS

Before

During

End of

Start

Timing

Cycle

Instantaneous 14-9/6-8

14-10/6-7

Delayed

11-12/4-5

11-13/4-3

BLACK-Circuit Closed

GRAY-Circuit Open

Automatic Timing & Controls

800.727.5646

atcdiversified.com