AZEL SINGLE STAGE AND TWO STAGE DIGITAL SETPOINT TEMPERATURE CONTROL: DST-777 User Manual

AZEL Relay

ZEL

TECHNOLOGIES

DST-777S, DST-777D
SETPOINT TEMPERATURE CONTROLS

INSTALLATION AND OPERATING INSTRUCTIONS

FEATURES

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Reliable Digital Electronic Accuracy

feature allows instant setpoint adjustment without

entering programming mode
Easy-to-Read Dual Digital Display with backlit which provides
constant readout of sensor temperature and setpoint
simultaneously, functional status and control settings. It also
allows precise setpoint and differential settings
Simple and user-friendly programming of setpoint
temperature, differential and cooling/heating modes
EEPROM memory retains control settings in the event of a
power failure
Wide adjustable setpoint with temperature range from -40 to
240°F and differential from 1 to 100°F. This enables the user to
optimize the system performance for any applications. A
tighter differential can be achieved (eg. 1°F or 1°C) than
conventional electromechanical controls
Advanced PWM (Pulse Width Modulation) Control to achieve
high control accuracy on single stage models
Choice of one or two stage models
One or two SPDT relay outputs. Model: DST-7772(two stage)
can handle one or two sensor inputs with two setpoints. When
using two sensor inputs, each setpoint can be corresponding
to one relay output. (Two units in one control)
LED indicates output relay status
Adjustable Anti-Short Cycle Delay to ensure the output relay
remains off for up to 20 minutes. This would avoid
unnecessary hard start and equipment wear
Selectable Fahrenheit or Celsius scales
Selectable Heat or Cool modes
Maximum and minimum memory for sensor temperature
Lockout mode to prevent tempering by unauthorized
personnel
Remote temperature sensor which can be extended to 500 ft.
Sensor failure and out of range indication
Easy installation and setup
Fast sampling rate (1 sec.) Of the sensor temperature for
instant control action
Easy-Connect Screwless Terminals for sensor connection
Backlit option: Auto (30 sec.)/OFF/ON
Power surge protection

QuickSet

APPLICATION

DST-777 series controls are microprocessor-based electronic

one or two stage setpoint temperature controls, designed to provide
one or two on/off controls (Single-Pole Double-Throw(SPDT) relay
outputs) for residential/commercial heating, cooling, air conditioning
and refrigeration applications.

The DST-777 is equipped with a Dual Digital display with backlit

that provides a constant readout of the sensor temperature and
setpoint simultaneously as well as the other programmed settings. The
front buttons allow the user to easily and accurately select the setpoint
temperature, differential and heating/cooling mode of the operation.
Unique

feature allows instant setpoint adjustment without

entering programming mode. This reliable and versatile control has a
very wide setpoint range, an adjustable differential and time delay that
makes it applicable in many different applications. The single stage
models have Pulse Width Modulation (PWM) control logic to prevent
overshoots and undershoots in slow responding systems with large
thermal mass such as pools or slabs. A sensor probe P-01 is supplied
with the control. This solid state temperature sensor probe can be
extended up to 500 feet.

QuickSet

MOUNTING

Mount the DST-777 controller to a suitable surface. Slotted keyholes and
standard holes are provided for mounting purposes.

SPECIFICATIONS

6 3/8”(W) x 6 5/8”(H) x 2 3/4”(D)

Sheath: Copper
Lead: 10” of 20 AWG heat resistence wire
Dimension: 3/8" OD x 13/16" length
Operating range: -60 to 255 F (-50 to 125 C)
Sensor: 10K ohm @ 77 F (25 C ± 1%) thermistor
Can be strapped on a pipe or inserted into a temperature well

DST-777S

Single Stage Setpoint Temperature Control

DST-777D

Single Stage Setpoint Temperature Control with 2 outputs

P-01 Sensor Probe:

Models:

Setpoint Temperature Range: -40 to 240°F(-40 to 116°C)
Temperature Display Resolution: 0.1°F/0.1°C
Differential Adjustment: 1 to 100°F(1 to 38°C)
Anti-Short Cycle Delay: 0 to 20 min. (1-Minute increments)
PWM Cycle Length: 30 to 1500 sec. (10-Second

Increments)

PWM Differential: 3 to 50°F (2 to 25°C)
Accuracy: ±1°C / ±1°F
Input: 10K ohm thermistor probe(included): P-01 (designed

for strap on a pipe or insert into a temperature well)

Temperature sampling rate: 1 second
Operating Voltage: 120 or 240 VAC, 50/60Hz
Relay: 1 or 2 x SPDT, 120VAC, Full Load 16A, 1Hp
Enclosure: Flame Retardant Plastic 94V0
Weight: 3.0 lbs
Dimension:

CAUTION!

1. To prevent electrical shock hazard, disconnect power supply before

installing.

2. All wiring must comply with national and local electrical codes,

ordinances, and regulations.
Never connect the load terminals to a load that takes more current than
the amount listed for the relay in the electrical ratings.

3. Azel Technologies is not responsible for damages resulting from misuse

of its products.

4. 12-18 gauge wire is recommended for 120 VAC conections;

or larger wire is recommended for sensor connections.

5. This literature is provided for informational purposes only.

gauge

MOUNTING THE SENSOR:

The sensor P-01 can be extended up to 500 with conventional 18 gauge

wire(or larger to keep additional resistance to a minimum). It is designed to
strap on a pipe or insert onto a temperature immersion well.

Senors should be strapped to the pipe with cable tie. The flat side of the

sensor should be resting on the pipe. In addition, they should be covered with
a layer of insulation to minimize the effects of ambient temperature for a more
reliable temperature reading.

The sensor P-01 can also be insert onto a 3/8”(10mm) or ½”(12.7mm)

ID temperature well.

Note: Do not run sensor wires parallel to other electrical wiring or telephone

wires. In case there is strong source of electromagnetic interference,
twisted pair 20AWG wire is recommended.