AZEL SINGLE STAGE User Manual

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

INSTALLATION AND OPERATING INSTRUCTIONS

TECHNOLOGIES

ZEL

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

FEATURES

Reliable Digital ElectronicAccuracy

QuickSet

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. (Twounits 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(30sec.)/OFF/ON

Power surge protection

feature allows instant setpoint adjustment without

SPECIFICATIONS

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:

P-01 Sensor Probe:

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

Models:

DST-777S Single Stage Setpoint Temperature Control DST-777D Single Stage Setpoint Temperature Control with 2 outputs

6 3/8”(W) x 6 5/8”(H) x 2 3/4”(D)

°°

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 therelay in the electrical ratings.

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

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

18 or larger wire is recommendedfor sensor connections.

gauge

5. This literatureis providedfor informational purposes only.

MOUNTING

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

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 orinsert 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 20AWGwire is recommended.

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ROUGH-IN WIRING

Loosen the screws on the top and bottom of the enclosure and remove the wiring covers by swinging them away from the base(grey color) with the edges of the covers as pivot(see Figure 1). The base has standard 7/8” (22mm) knockouts which accept common wiring hardware and conduit fittings. Before removing the knockouts, check the wiring diagrams and use the chamberwith common voltages.

Side view

Figure 1

OPERATION

Liquid Crystal Display

In normal operating mode, the upper LCD display the current sensor temperature and thelower LCD display the setpoint temperature. The display is also used with the Up Arrow and Down Arrow buttons to adjust the setpoint temperature, differential and heating/cooling modes ofthe operation.

LCD Blue Backlit Options: set by slide switch on the front panel

ON - backlit is turned on. OFF - backlit is turned off. Auto - backlit is turned on for 30 secs when any button is pressed.

L.E.D. SYSTEM STATUS INDICATION LIGHTS:

RED light indicates that theSPDT relay output is energized.

Heating Mode and Cooling Mode:

set by keypad

Normal Control Mode(ON/OFF Control): SetPWM slide switch to OFF

The control outputs will turn on the equipment when there is a demand for heating or cooling. When the demand is satisfied, the control outputs will turn it off.

Pulse Width Modulation (PWM) Mode(PWM CONTROL): Set PWM slide switch to ON

The single stage models (DST-777S, DST-777D) offer optimum control by means of a Pulse Width Modulation(PWM). In PWM, the ON and OFF cycle vary depending on the difference between the sensor and setpoint temperature. The bigger difference between the sensor and setpoint temperature, the longer the relay is switched ON. When the sensor temperature approaches the setpoint temperature, the ON time become shorter and shorter. Pulse Width Modulation guarantees precise control response. This function prevents overshoots and undershoots in systems with large thermal mass (eg.slabs or pools).

Figure 3 shows the operationof relay on Heating Mode duringPWM cycle:

If the sensor temperature is half of the PWM Differential above the

setpoint temperature (in this exampleis: 79°

If the sensor temperature is half of the PWM Differential below the

setpoint temperature (in this exampleis: 71 F (75 - 8/2),relay is ON.

If the sensor temperature is between 71 F and 79 F , PWM is in action.

F (75 + 8/2), relayis OFF.

°° When the sensor temperature crosses the rising slope of the triangle wave generated by the control, relay is turned ON during the shaded region. When the sensor temperature passes the falling slope of the triangle wave, the relay isturned OFF during the unshaded region.

The pulse width (the relay ON time within one cycle) is modulated in

according to how far the sensor temperature deviates from the setpoint temperature.

If sensor temperatureis the same as the setpoint temperature, the pulse

width is half (50%) ofthe cycle length.

If the sensor temperature is higher than the setpoint temperature, the

pulse width allows shorter periodof ON time

If the sensor temperature is lower than the setpoint temperature, the

pulse width allows longer periodof ON time.

If PWM mode is selected,the minimum time delay is disabled.

The principle of operation on Cooling Mode is the same with the shaded

and white area reversed inFigure 3.

Heating Mode

(factory setting): The control output will turn on when the sensor temperature falls to the setpoint temperature minus the differential amount. The control output will turn off when the sensor temperature reaches the setpoint temperature. For example, if setpoint = 68F, Differential =3F, then output is on at65F and off at 68F.In other words, when the heating mode is chosen, the differential is below the setpoint. The relay will deenergize as the temperature risesto the setpoint. Refer to Figure2.

Cooling Mode

: The control output will turn on when the sensor temperature rises to the setpoint temperature plus the differential amount. The control output will turn off when the sensor temperature reaches the setpoint temperature. For example, if setpoint = 75F, Differential = 2F, then output is on at 77F and off at 75F. In other words, when cooling mode is chosen, the differential is above the setpoint. The relay will deenergize as the temperature fallsto the setpoint.

The control output turned onmeans:

From the isolated SPDT relay output, “NO” are normally open contacts which close and “NC” are normally closedcontacts which open when thecontrol output is on.

Temperature

Cooling

Mode

Setpoint

Figure 2: Operation of relay in according to Setpoint and Differential

Settings for both Heating and Cooling Mode

ON (relay energized)

OFF

(relay de-energized)

OFF

Heating

Mode

Grey Area = ON region White Area = OFF region

Temperature

79 F°

Setpoint =75F°

71 F°

Relay turned On

(Pulse width)

Figure 3: Operation of relay on heat mode during Pulse Width Modulation(PWM) cycle

Relay Turned Off

PWM Cycle Length

Sensor Temperature Curve

PWM Differential =8 F°

Time

Anti-Short Cycle Delay: set by keypad

Anti-Short Cycle Delay can be set to ensure the output relay remains off for up to 20 minutes (default is 0 mins) after relay is de-energized. This is adjustable from 0 to 20 min with 1 minute increments. In other words, this function establishes the minimum time that the output relay remains de-energized before the next on-cycle. It does not allow the output relay to re-energize until the programmed time delay has elapsed. The delay is activated when the control is first turned on, but can be skipped within the first 3 seconds by pressing the “SET” key onceand go to normal operating mode (Note:SET key at this stage will not perform any other function except terminating the time delay).

Anti-Short Cycle Delay is available only whenPWM is off .

When the delay is activated, the Upper LCD shows the current temperature and the lower LCD shows blinking “AC” which stands forAnti-Cycle. Also, in case there is a demand forheating/cooling, the red LED for relay outputwill be blinking indicating that anti-cycle featureprevent relay from energizing.

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WIRING THE CONTROL

Fuse

Refer to Figure 4 for typical wiring connections for DST-777S and Figure 5 for DST-777D . Do not

Sensor

Temperature

use wire larger than 12 AWG as jumper between terminal blocks (eg. “120V” and “C”)

Checkout

Setpoint

Temperature

Relay Output

Status

Indicator LED

! Before power is applied to the

control, make sure that the installation and wiring connections are done correctly. Also, ensure that the wires connecting to COM and 120V are not touching each other.

! Ensure that wires of the senor

probe are not touching each other

POWER ON

PWM

OFF

S1 S1

SENSOR INPUTS

SENSOR

PROBE

(P-01)

PWM Switch

(HOT)

NCCNO

RELAY 1

LOAD

240V COM 120V

AC INPUT

(COM)

120 VAC

Figure 4: Typical Wiring Diagram for DST-777S

with 120Vac Load

Terminal Representations:

240V is the hot of the 240Vac line voltage

SET Button

Up (Arrow)

Button

Down (Arrow)

Button

Reset Button

Backlit Switch

COM is the neutral or ground of the line voltage 120V is the hot of the 120Vac line voltage

RELAY 1/RELAY 2 NC is Normally Close of SPDT switch and opens when the relay is energized C is Common of the SPDT switch NO is Normally Open of the SPDT switch and closes when the relay is energized

SENSOR INPUT S1 S1 are the input terminals for sensor probe P-01

LOAD

NC C NO

RELAY 2

LOAD

240V COM 120V

AC INPUT

(COM)

120 VAC

(HOT)

NCCNO

RELAY 1

Figure 5: Typical Wiring Diagram for DST-777D

with 120Vac Loads

OFF

S1 S1

SENSOR INPUTS

SENSOR

PROBE

(P-01)

PWM

All the slide switches (Backlit and PWM) should be set before the control is powered up (so the desired switch settings are scanned by the microprocessor). However if the settings onthe slide switches are changed afterpower is supplied, press the key sothat the switch settings can beupdated.

RESET

When the control is powered up, the model ID is displayed. Then the control will run Anti-short cycle delay(if any) and goes into normal operating mode in which the Upper LCD will displaythe current sensor temperature and theLower LCD will display the setpointtemperature.

SETTING THE CONTROLS

QuickSet Feature:

Quickset allows the user to change the setpoint temperature instantly without entering the program mode. Simply press (increase) or (decrease) key during the normal operating mode. Whenthe key is pressed, the setpoint isflashing toindicate that the setpoint value can be changed.Press the button again to adjust the setpoint (press and hold for auto repeat function). Press key when finish or just walk away and it will return to normal mode after 30

Up/Down UP/Down

SET

seconds.

Program Mode:

General Note:

Press and hold the Key or Key to change the value continuously(auto repeat function).

To return to normal operating mode from the program mode, press and hold the key for 3 seconds. However, the system also return to normal operating

mode if no key ispressed for 30 seconds.

During the program mode, each time key is pressed, the data will be saved into the EEPROM and advance to the next setting(parameter). If no change of

value is required, just press key once to go tothe next step (parameter).

Up Down

SET

Programming Steps for NormalControl Mode (ON/OFF Control)

Note: Set PWM slide switchto OFF

Steps

Step1

Step 2

Procedures

To start programming, press the key for 3 seconds to access the

SET

Fahrenheit/Celsius mode. The lower LCD display will show the current status, either for degreesFahrenheit or for degreesCelsius. This annunciator will be

flashing. Then presseither or keyto toggle between the or scales.

Press key again to accessthe setpoint mode. Thelower LCD will display the

SET

current setpoint (flashing) and the upper LCD will display annunciator. Then press either the key to increase or the key to decrease the setpoint to

Up Down

Up Down F C

the desired setting. ** Please note that this value as well as all the temperature related value are

in degree Fahrenheit as setin step 1.

Description

Fahrenheit or Celsius Scale

The default value is

Setpoint Temperature

Default setting is:

UP Down

LCD Display

75F

Si 75f

Step 3

Step 4

Step 5

Press key again to access the differential mode. The lower LCD will display

SET

the current differential (blinking) and the upper LCD will display annunciator. Then press either the key to increase or the key to decrease the

Up Down

dF1

differential to thedesired setting.

Press key again to access the heating or cooling mode. The upper LCD will

SET

display the current mode, with flashing annunciator, either for heating or for cooling.Then press either the key or the key to toggle between the

or operation.

C1 H1

Press key again to access the Anti-Short Cycle time delay. The lower LCD

SET

Up Down

H1 C1

will display the current time delay(blinking), in minute and the upper LCD will display . Then press either the key to increase or the key to

AC1 Up Down

decrease the delay to the desired setting. The increment is in 1 minute. Press

key again to go backto normal operating mode.

SET

Differential Temperature

Default setting is:

Cooling or Heating

Default setting is:

Anti-Short Cycle time delay

Default is: minutes

8f i

Ac i

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Programming Steps for PWMControl Mode

Note: Set PWM slide switchto ON

Steps

Step1

Step 2

Step 3

Step 4

Step 5

Review Mode:Setting

Press both and keys at the same time to review the current control settings. Then Press (or ) key to scroll through the settings in the same order as Program Mode (F/C scale, Setpoint, Differential, Heating/Cooling, Anti Cycle Time Delay etc.). To exit to normal mode,,press

Down

key

Down

and at the same time. In this mode, the settings cannot be changed.

Max/Min Memory Mode:

Maximum and Minimum sensor temperature are recorded in the memory. To view the max./min. Temperature:

1. From normal operating mode, press

2. Press once more to exit to

Reset:

Press key if the following changes are made after the control is

RESET

powered up:

Slide switch settings

ime related parameters such as anti-cycle time delay or PWM cycle

length After reset, the control will start from the beginning and run on these new settings

Procedures

To start programming, press the key for 3 seconds to access the Fahrenheit/Celsius mode. The lower LCD display will show the current status, either for degreesFahrenheit or for degreesCelsius. This annunciator will be

flashing. Then presseither or keyto toggle between the or scales.

Press key again to accessthe setpoint mode. Thelower LCD will display the

SET

current setpoint (flashing) and the upper LCD will display annunciator. Then press either the key to increase or the key to decrease the set point to the desired setting. ** Please note that this value as well as all the temperature related value are

in degree Fahrenheit as setin step 1.

Press key again to access the heating or cooling mode. The upper LCD will

SET

display the current mode, with flashing annunciator, either for heating or for cooling. Then press either the key or the to toggle between the or operation.

Press key again to access the PWM differential mode. The lower LCD will

SET

display the current PWM differential (blinking) and the upper LCD will display

annunciator. Then press either the key to increase or the key to

PdF Up Down

decrease the differential to thedesired setting.

Press key again to access the PWM Cycle Length. The lower LCD will

SET

display the current PWM Cycle Length(blinking), in seconds and the upper LCD will display . Then press either the key to increase or the key to decrease thedelay to the desired setting. The increment isin 10 seconds. Press

key again to go backto normal operating mode.

SET

Up Down

one more time (eg. AC1) or press both

keys

SET

second).The upper LCD will display the maximum recorded sensor temperature and the lower LCD will display the minimum recorded sensor temperature.

normal operating mode.

Down

key once (eg. Just for 1

SET key

Up Down

CyC Up Down

Up Down F C

SET

Up Down C1

Upfrom the last setting

T1 max

Min

95f 52f

Description

Fahrenheit or Celsius Scale

The default value is

Setpoint Temperature

Default setting is:

75F

LCD Display

Si 75f

H1 C1

Cooling or Heating

Default setting is:

PWM Differential Temperature

Default setting is:

PWM Cycle Length

Default is:

300 seconds.

P8f

C8c

300

Keypad Lock:

Keypad can be locked to prevent tempering by unauthorized personnel. This is done by pressing , and keys at the same time for three

seconds. The word “ ” appears on the LCD screen for 3 seconds which indicates that the keypad is locked. Then input from the keypad is disabled.

SET Up Down

Press , and keys at the same time again for another three seconds to unlock the keypad. The word “ ” appears on the screen for 3 seconds which indicates that thekeypad is enabled.

Factory setting: unlock

Troubleshooting Error Messages

If the upper LCD display shows flashing “Err” and the lower LCD display shows S1, the sensor probe is short circuited.

If the upper LCD display shows flashing “LLL” and the lower LCD display shows S1, the sensor probe is open circuited or the sensor temperature is out of the lower range. The relay 1 will be deenergized.

Action: Verify if the sensor temperature is open circuited or out of the lower

range. If not, check for proper sensor operation by comparing it to a known ambient temperature. The easiest way is to get an Azel Technologies DS-60P digital temperature gauge which displays two P-01 sensor temperature. Connect this sensor to DS-60P and compare the reading with the good sensor. The second way is to obtain the P-01 resistance table from the manufacturer. Then use a ohmmeter to measure the resistance across the two sensor leads and compare to the temperature reading at the sensor location.

If the upper LCD display shows flashing “HHH” and the lower LCD display shows S1, the sensor temperature is out of the upper range. The relay 1 will be deenergized.

Use the same procedures as above with flashing “LLL”

SET Up Down

E88

Lll

Hhh