Smarttemp SMT‐770 Programmable Thermostat Installer Manual

Smarttemp SMT‐770 Programmable Thermostat

Introduction

This document it not typically left with the user as it contains information on setting values which, if not correctly set may damage the heating, cooling or air conditioning system or seriously affect its performance or energy consumption.

Great effort has been taken to making the  SMT‐770  thermostat system intuitive,  reliable and easy to install. Using a common sense approach to the installation will ensure this  product is installed easily and to the customer’s satisfaction.  Please read and understand this instruction manual so that installation, testing and commissioning process is undertaken in an efficient and effective manner.
This manual is to be used in conjunction with the supplied user manual.
Great care has been taken in the preparation of this manual. Smart Temp Australia P/L takes no responsibility for errors or omissions contained in this document. It is the responsibility of the user to ensure this thermostat, or the equipment connected to it is operating to their respective specifications and in a safe manner.
Due to ongoing product improvement, Smart Temp Australia P/L reserves the right to change the specifications of the SMT‐770 thermostat (or its components) without notice.
All rights reserved. © Smart Temp Australia P/L 2011
Intellectual rights apply.

Installation

As with any  air conditioning project undertaken,  careful installation is the key to a  successful outcome. Time taken during this installation process will be rewarded with a happy customer and fewer callbacks.
The steps required to install the SMT‐770 thermostat are ‐

1. Read and understand this manual and the User manual.
2. Mount the SMT‐770 back plate in a suitable location.
3. Set the 8 DIP switches to match the need of the project/user.
4. Wire the optional remote temperature sensor(s) or switches if required.
5. Power up the air conditioning system.
6. Set the installer software options (if required).
7. Program and set up the SMT‐770 thermostat. (The User Manual will assist with this).
8. Test the heating, cooling and other functions – Commissioning.

For convenience, the layout of this manual is in the same order as the steps listed above.

Mounting the SMT‐770 thermostat.
The  SMT‐770  can  only be as accurate as the onboard temperature sensor,  or its optional remote temperature sensor(s) permit. It is therefore essential that the SMT‐770 be installed in a location that is typical of the ambient room temperature. Do not install the thermostat in a  draft,  near a  floor,  behind doors  or on a  non‐insulated external wall. Also avoid placing the thermostat in areas where the air movement is limited, affected by direct sunlight, or other areas not  “typical” of the temperature of the room.

Further,  when mounting the  SMT‐770  be aware that drafts may travel down the inside of cavity walls, (especially if mounted on external walls)  and enter the back of  the thermostat or sensor enclosure through the  cable entry holes in the wall. It is important to fully seal  these  holes  to  prevent  any  drafts  affecting  the  internally mounted temperature sensor. It is recommended  to  mount  the  SMT‐770  or  remote  sensors  between 1.5 & 1.7 metres from the floor where possible.

Move  the control  wires  through  the  large  opening  in  the  thermostat  base  plate  then  place the thermostat base on the wall and using appropriate screws, firmly attach the thermostat  base  to  the wall.  Block  any  holes  where  cables  enter  the  back  of  the  thermostat to prevent drafts entering through these holes affecting the sensor.

Setting the hardware switches

Switch	Off	On
Sw1 – Fan Speeds	1 Speed Fan	3 Speed Fan
Sw2 – Equipment Type	Heat Cool	Heat Pump (O/B terminals)
Sw3 – Stages	1 Stage	2 Stages
Sw4 – Reversing Valve If Sw 2= ON – Heat Pump Sw4 – Fan Mode If Sw 2= OFF – Heat/cool	Energise in cool (O)	Energise in heat (B)
	Fan Control by Heater (HG)	Fan Control by T’stat (HE)
Sw5 – Anti cycle timer	Off	4 Minutes
Sw6 – Operation	Manual Thermostat	Programmable Thermostat
Sw7 – Minimum Run	2 minutes	6 Minutes
Sw8 – Program Type If Sw 6= ON – Programmable Sw8 – Set points If Sw 6= OFF – Manual	Commercial Program	Residential Program
	Single Set point	Two Set points

Typical  drawings  have  been  provided  on  page  12  of  this  manual  that  will  assist with the selection of the correct positions for these function switches.

Switch 1 – Relay Assignment
The SMT‐770 is fitted with 5 relays capable of switching up to 24VAC @ 1Amp. Switch 1 sets the function of these relays as either 3 fan speeds with 1 heat and 1 cool operation or single fan speed with 2 heat and 2 cool, in either HP (heat pump / reverse cycle) or HC (heat with add on cool) mode.

Switch 2 – Equipment Type.
Both  heat  with  add  on  cool  or  heat  pump  types  of  systems  can  be  controlled  by  the  SMT‐770.

• Heat Cool System uses the “W” terminal(s) only for heating and the “Y” terminal(s) only for cooling.
• Heat  Pump systems  use  the  “Y”  terminal(s)  for  BOTH  heating  and  cooling  (the  compressor). The “W1” terminal to control the reversing valve which determines heating or cooling mode.

Switch 3 – Equipment Stages.
When it is necessary to control a single stage A/C system fitted with auxiliary heating elements,  turn  Sw3  OFF  thereby  selecting  single  stage  mode.  Heating  elements  controlled by the W2 output are now assigned as stage 2 heat.

Switch 4 – Reversing Valve or Fan Mode
When  the  SMT‐770  is  set  for  Heat  Pump  mode  (Sw2  is  on)  then  this  switch  sets  the  reversing valve logic (O/B). When the SMT‐770 is set for Heat Cool mode (Sw2 is off) then this switch sets the mode for the Heater fan logic (HG or HE mode).

Switch 5 – Anti Cycle Timer
To  protect  some  A/C  systems  it  is  preferred  that  under  no  circumstances  should  the  compressor start within 4 minutes of it switching off.
Note: when power is first applied to the SMT‐770 it “assumes” that the compressor has just stopped and applies this anti cycle delay time before starting.

Switch 6 – Thermostat Operation
To  suit  the  varying  requirements  of  the  user,  the  SMT‐770  can  be  set  as  a  programmable thermostat using the time clock to automatically control the building temperature  to  a  programmed  temperature  profile  or  to  the  very  simple  to  operate  manual mode where the user turns the thermostat on or off and adjusts the temperature set point manually.

Switch 7 – Minimum Run Time.
To conserve energy and protect the A/C system it is recommended to limit the number of  times  the  heating  and  /  or  cooling  system  can  run  in  1  hour.  This  switch  sets  the  minimum heating and cooling equipment to a minimum run time of 2 or 6 minutes. Once the heating or cooling has started it must run for this minimum set time. The LCD will flash the word “Heating” or “Cooling” whenever this timer is in effect.

Switch 8 – Thermostat Control Logic.
This  switch  also  has  two  functions  based  on  the  position  of  switch  6.  When  the   SMT‐770 is set as a programmable thermostat, switch 8 determines whether a commercial  program  or  residential  program  is  selected.  When  switch  6  has  the   SMT‐770 used as a non programmable thermostat, this switch sets single set point mode  (imitating  a  simple  mechanical  thermostat)  or  whether  a  separate  heating  and  cooling set point can be selected by the user. Two set point mode also permits the user to select a separate day and night set point if required.

Terminal Functions

The SMT‐770 is fitted with a set of terminals marked “TT”. Details on the functions that the “TT” terminals perform is provided below. See the advanced installer setting menu on page 19 of this manual for setting the function of this set of terminals. The wiring used in the following examples are not polarity dependent and do not normally require screened cable.
Note:  The  SMT‐770  can  use  multiple  sensors  if  required  for  averaging.  Drawings showing these various configurations are shown on page 37 of this manual.

Outside Air Sensor Wiring
Set “TT= OA” in the advanced installer menu.
The SMT‐770 can display the outside air temperature if desired. Some advanced control functions such as high and low balance points rely on this sensor to be fitted Figure 1
for  correct  operation.  Using  a  single  pair  of  wires
connect  the  “TT”  terminals  in  the  SMT‐770  to  the  two  terminals  in  the  outside  air  temperature sensor. (See figure 1). If the outside air sensor fails two dashes will be shown on the LCD where the outside air temperature would normally be displayed to alert you of the problem.

Remote Air Temperature Sensor Wiring.
Set “TT= RS” in the advanced installer menu. (Default) When  you  wish  to  measure  the  temperature  from  a  location distant from the SMT‐770, simply connect a  remote  temperature  sensor  to  the  “TT”  terminals  in  the SMT‐770. This will automatically disable the sensor fitted to the SMT‐770 and use the  remote  temperature  sensor(s)  to  control  the  room  temperature  (See  figure  1  above). Should you wish, you can easily switch the remote temperature sensor on and off thereby switching temperature sensing locations between the remote temperature sensor and the SMT‐770 temperature sensor when required. Simply fit an inline switch in the sensor wiring or order Smart Temp part number RS‐01S sensor. (See Figure 2.)

Averaging Temperature Sensors
Set “TT= AV” in the advanced installer menu.
The  SMT‐770  can  average  the  sensed  temperature  equally  between  the  remote  temperature sensor(s) and the one fitted to the SMT‐770 if required. See figure 1 on the previous page for details on wiring the sensor. The SMT‐770 will auto‐detect this sensor  and  automatically  average  the  two  sensors  values  to  control  the  room  temperature.

Remote ON / OFF Function

Set “TT= OF” in the advanced installer menu.  
The SMT‐770 can be connected to an external dry contact. When this contact is closed the SMT‐770 will turn OFF. See figure 3. When the SMT‐770 has been switched OFF via the “TT” terminals the word “OFF” will flash in the LCD to indicate that this has been the shutdown method. The SMT‐770 will return to the user settings when this switch is open.Using the “Occupancy Mode”
Set “TT= OC” in the advanced installer menu.
The SMT‐770 can alternate between the user preferred set points and an installer pre programmed  set  point  when  required.  Simply  wire  a  remote  switch  to  the  SMT‐770  “TT” terminals (see figure 3). When the switch is open the user settings will control the room  temperature.  When  the  switch  is  closed  the  Installer  “Oc”  (Occupied  Cooling  value) & “Oh” (Occupied Heating value) settings will be used to control the room temperature.

Supply Air Temperature Monitoring
Set “TT= DA” in the advanced installer menu.
In  this  mode,  the  SMT‐770  will  broadcast  this  sensor  temperature  value  to  ModBus  ONLY, this value is not used by the SMT‐770 nor is it displayed on the LCD. It is expected that this information is used for supervisory functions or equipment control feedback. Also,  as  this  is  an  analogue  input,  by  monitoring  a  switched  resistor  network  your  supervisory software can decode a number of digital states.

Typical Drawings

The  SMT‐770  has  the  capacity  to  control  a  wide  selection  of  heating,  cooling  and  air  conditioning systems. Using the 8 DIP switches and many installer software options, the SMT‐770 is capable of providing many different control methods from its 5 fitted relays. Examples of only the most common types of control wiring have been provided below.
You  may  need  to  modify  these  drawings  slightly  to  specifically  suit  your  individual  needs, alternatively contact Smart Temp at [email protected] or an authorised distributor for installation information specific to your application.

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =Off (HC System)
• Sw3=Off (Single Stage)
• Sw4= Off (HG)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements Tip
  Set Installer menu Fn=H

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =Off (HC System)
• Sw3=Off (Single Stage)
• Sw4= N/A
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements Tip
  Set Installer menu Fn=C

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =Off (HC System)
• Sw3=Off (Single Stage)
• Sw4= Off (HG)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements

Switch Settings
Sw1 = Off (1 speed fan) Sw2 =Off (HC System) Sw3=On (Two Stage) Sw4= Off (HG)
Sw5= Installer preference Sw6= User requirements Sw7= Installer preference Sw8= User requirements

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =On (HP System)
• Sw3=Off (One Stage)
• Sw4= On Heat (B)/ Off Cool (O)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements
  Note – Set SW4 to suit the system

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =On (HP System)
• Sw3=Off (One Stage)
• Sw4= On Heat (B)/ Off Cool (O)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements
  Note – Set SW4 to suit the system

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =On (HP System)
• Sw3=Off (One Stage)
• Sw4= On Heat (B)/ Off Cool (O)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements
  Note – Set SW4 to suit suit the system

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =On (HP System)
• Sw3=On (Two Stage)
• Sw4= On Heat (B)/ Off Cool (O)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements
  Note: Set W3=EH in the installer menu.

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =Off (HC System)
• Sw3=Off (Single Stage)
• Sw4= Off (HG)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements Tip
  Set Installer menu Fn=H

Switch Settings

• Sw1 = Off (1 speed fan)
• Sw2 =Off (HC System)
• Sw3=On (Two Stage)
• Sw4= Off (HG)
• Sw5= Installer preference
• Sw6= User requirements
• Sw7= Installer preference
• Sw8= User requirements

Attaching the thermostat

Check  that  the  position  of  the  8  DIP  switches  matches  the  requirements  of  the  equipment being controlled and the specific requirements of the user. Detailed information on the 8 DIP switches can be found on page 6 of this manual.
Check the wiring matches that of the equipment the SMT‐770 is to control and that all wiring  is  tight  and  not  likely  to  short  between  adjacent  wires.  Equipment  wiring  information can be found on page 12 of this manual. If  using  the  ModBus  communication  capability  of  the  SMT‐770,  ensure the “A”, “B” & “T” data wires are in the correct position as an  error  here  may  affect  the  communication  of  the  entire  network. See page 38 for detailed wiring of the communications
port of the SMT‐770.
Using  masking  tape  or  similar,  block  the  hole  in  the  wall  where  the  wiring  enters  the  back  of  the  thermostat  to  prevent  drafts  that  may  travel  down  the  inside  of  the  wall  cavity affecting the accuracy of the internally fitted temperature sensor.

Remove and discard the plastic tab on the internally fitted backup battery so that the battery is now in circuit and operating. Take care not to damage the battery holder when doing this.
When attaching the thermostat to the base, avoid twisting the case as this may stress the LCD and cause it to crack. Avoid running wiring near the internally fitted sensor.
Take care not to damage or crush the temperature sensor between the two half’s of the case when you close the Chameleon case. Check this sensor location.

Advanced Installer Settings

The  SMT‐770  is  fitted  with  many  advanced  functions  that  can  be  finetuned  by  the  installer to specifically match the needs of the project of the user.
Normally these functions will not need to be altered from the factory default position however, there may be times when you wish to alter a setting or control capability so that the SMT‐770 performance will perfectly match a particular application. On the next few pages there is detailed explanation of these functions and their range of control.
While in the advanced installer menu, all SMT‐770 equipment control functions will be suspended. Normal equipment operation will continue when you have exited this menu (after any anti cycle delays or safety delays have terminated).

Entering the Installer Menu
To enter the Installer menu, press and hold the O/RIDE button for 15 seconds. After 15 seconds the LCD will show “88:15” (eight eight one five).
Adjust  this  value  to  “88:21”  –  (eight  eight  two  one)  the  factory  default  PIN  (or  your  previously selected value) by using the up () or down () button. Tap the O/RIDE button to enter the menu.
If you have entered the correct PIN you will be given the first menu option, if you have entered an incorrect PIN you will be exited from this menu.

Using the Installer Menu
To move forward through the Installer menu items tap the “O/RIDE” button.
To move backwards through the Installer menu items tap the “PROG” button.
To adjust a value in the Installer menu tap the () or down () buttons.
To exit the installer menu tap the “Mode” button, the “Fan” button or wait 60 seconds.
Default Installer Values are shown in the examples below.

PN = 21      Keyboard Lock PIN This is the required PIN for future entry into the Installer menu. Range 00 to 99 in 01 steps. To prevent accidental PIN changes, you must press and hold the or buttons for longer than 1 second to change the PIN value. (Caution, if you change this value and forget your new PIN, you may need to return the SMT‐770 to place of purchase for unlocking, there may be a fee for this service)

LC = 0          Keyboard Lock level Programmable Mode (SW6=ON) LC = 00 ‐ Key board Lock OFF. LC = 01 ‐ All buttons are locked except the Temperature +/‐ buttons*. LC = 02 ‐ All buttons are locked except the O/Ride button & Temp +/‐ buttons*. LC = 03 ‐ Fan and Program buttons are locked*. LC = 04 ‐ Fan, Program and Override buttons are locked *. LC = 05 ‐ All buttons locked except O/Ride. LC = 06 ‐ All Buttons locked. Manual Mode (SW6=Off) LC = 00 ‐ Key board Lock OFF. LC = 01 ‐ All buttons are locked except the Mode button. LC = 02 ‐ All buttons are locked except the Mode and temperature +/‐ button*. LC = 03 ‐ Fan & O/ride buttons are locked*. Mode button can only select Auto (Heat & Cool) and off. LC = 04 ‐ O/Ride Button is locked*. Mode button can only select Auto (Heat & Cool) and off. (*Note the temp +/‐ buttons range can be limited in the HL & CL menu )

HL = 49 (120F)              Heating Limit (or High Limit) The highest heating value permitted to be set by the user. Adjustable between 0~35c (32~95F).

CL = 5 (41F)                   Cooling Limit (or Low Limit) The lowest cooling value permitted to be set by the user. Adjustable between 5 ~37c. (41~98F).

CF = C          Temperature display Format Deg C or deg F display type. (effects all user and installer menu items)

C1 = 0.0      Fitted Sensor Calibration Calibration offset for the internal sensor. Adjustable range +/‐ 4.5 deg C (+/‐9 F). in 0.1 steps

tC = 12        Time Clock tC = 12 ‐ 12 Hour Time Clock. tC = 24 ‐ 24 Hour Time Clock. tC = 0 ‐ No time clock shown (Manual mode only –SW6=off)

td = 0          Temperature Display TD = 00 ‐ The SMT‐770 will display both the room & set temperature. TD = 01 ‐ The SMT‐770 will display set temperature only.

AH = 2   After Hours Override Timer Start / Stop Mode ‐ Commercial Thermostat Mode (Sw6=on, Sw8=off) After hour run time period ‐ Adjustable range 0 (off) to 12 hours in 0.5 hour steps. Setback (1, 2, 3, 4) mode – Residential programmable mode (Sw6=on, Sw8=on) Temporarily program override period. Off= Override till next program change or 1‐12 hours (fixed time override)

St = Off       Start Program temperature (Commercial Mode) Start/stop mode Only. (Sw6=on, Sw8=off). This sets the default temperature that will be used each time the “Start” program begins regardless of any adjustments the user may have made previously. Adjustable between OFF, 15~35c. (59~95F). If set to off, the user set point will not be automatically reset to a default value each day.

SC = OFf  Stop Cooling temperature (Commercial Mode) Start/stop mode Only. (Sw6=on, Sw8=off). Cooling temperature that will be maintained when running the “STOP” program. (Night Setback) Adjustable between 5 ~37c. (41~98F) + OFF.

SH = OFf  Stop Heating temperature (Commercial Mode) Start/stop mode Only. (Sw6=on, Sw8=off). Heating temperature that will be maintained when running the “STOP” program. (Night Setback) Adjustable between 5 ~35c. (41~95F) + OFF.

db = 0.5/1 Single Set Point Dead band (See page 33 for more information) Dead band between heat and cool set point when in single set point mode (sw8 off). Adjustable between 0 and 5 deg in 0.5 c steps

Fo = 0/2     Fan Options ‐ Advanced Fan Functions This function is only enabled when the selected fan mode is Fan On. “FAN ON” will be displayed in the LCD to confirm this mode.   FO = 0 ‐ (Default Residential mode).The fan will run continuously ‐, 24 hours a day 7 days a week.   FO = 1 ‐ The fan will continue to run after the cooling stops to ensure the maximum fresh air ventilation and to aid in cooling. The fan will stop after the heating stops. (This is done to prevent cold drafts that may occur on cold days when A/C system is heating).   FO = 2 ‐ (Default in Start Stop Mode).Available only if in Programmable Mode (Sw6=on). The Fan will Run continuously from program # 1 (or Start) Program to program #4 (or Stop) program and then run in AUTO mode overnight to maintain the night time set points.   FO = 3 ‐ Available only if in Programmable Mode (Sw6=on). This mode is the combination of option 1 and option 2 given above.

FP = 0          Fan Purge Time Period (Fan run on) If fan mode is Auto Fan, the indoor fan will run for FP=XX minutes after heating or cooling has stopped to extract any stored energy in the coils etc – (Necessary for electric element heating). Adjustable between off to 5 minutes in 1 minute intervals.

Fn = A   Function ‐ Available Equipment Modes FN = A ‐ Select if controlling a Heating & Cooling system. FN = C ‐ Select if controlling a Cooling only system. (disables heating menus) FN = H ‐ Select if controlling a Heating only system. (disables cooling menus) FN=‐‐ ‐ (Dash) This mode will set SMT‐770 to Heat only, Cool only or OFF . (Emergency heat will also be selectable if fitted)

H3 = Of       W2 relay Function Only operates in single fan speed HP mode. (Sw1=off & Sw2=on). H3 = Of ‐ W2 relay is used as 2nd (or 3rd) stage Auxiliary heat. H3 = EH ‐ W2 relay is used to control an Emergency Heating system. H3 = AH ‐ W2 relay is used to control a Add On Heat system. H3 = FF ‐ SMT‐770 set up in “Fossil Fuel” Mode (Comp stops with Aux heat) H3 = AL ‐ SMT will permit both Aux heat & E. Heating mode (both use W2 relay)

tt=RS           TT terminal Function (see page 9 for more detail on this function) tt = OA ‐ Connect the outside air temperature sensor to the TT terminals to display the outside Air Temperature. (Required for all outside air control functions to operate.) tt = RS ‐ Connect the remote room temperature sensor to the TT terminals to measure the temperature at a remote location away from the SMT‐770. (Note: This completely disables the temperature sensor fitted to the SMT‐770) tt = AV ‐ The TT terminals will average the temperature measured by the SMT‐770 internal sensor and remote room temperature sensor(s). tt = OF ‐ A closed contact on the TT terminals will switch the SMT‐770 On or OFF. (More detail on this function provided on page 11 of this manual.) tt = OC ‐ A closed contact on the TT terminals will switch the SMT‐770 to Occupied Mode, where the oC & oH temperatures will replace the user set temperatures. (See page 11 of this manual for more detail on this function.) tt = DA ‐ The SMT‐770 will broadcast the measured temperature from the remote temperature sensor via ModBus. It will not display this value on the LCD, nor is it used for any control option. This mode is intended to provide system feedback to the ModBus master only. tt = 2p – The function is intended for controlling a 2 pipe fan coil. The mode of the thermostat (heating or cooling) will be determined based solely on the temperature as measured by the remote sensor. The remote sensor (RS‐1D) is typically strapped to the fan coil water supply line. The mode button only permits the user to select OFF or ON, where on is either heat or cool mode based on the remote sensor temperature.

AF = 0         Anti‐Freeze Function AF = 0 ‐ Antifreeze function off. AF = 1 ‐ Room temperature will not be permitted to fall below 5c (41F).

oH = Off Occupied Mode Heat Set (see page 11 for more information). Only operates if TT=OC. This is the heating temperature that will be used in “Occupied mode” and will temporarily replace the user heat set point while the TT terminals are shorted together. Adjustable range 0‐35c (32 – 95f)

oC = OFf Occupied Mode Cool Set (see page 11 for more information). Only operates if TT=OC. This is the cooling temperature that will be used in “Occupied mode” and will temporarily replace the user cool set point while the TT terminals are shorted together. Adjustable range 5‐37c (41 – 98f)

SP = 2          Stage 1 Span (See page 33 for an overview of this control function) Hysteresis for Stage 1. (difference between heating and cooling turning on and off) Sp = 1          0.5c SP = 2          1.0c Sp = 3          1.5c

Sd = 2          Stage 2 Span (See page 33 for an overview of this control function) Hysteresis for Stage 2. (difference between heating and cooling turning on and off) Sd = 1          0.5c Sd = 2          1.0c Sd = 3          1.5c

S3 = 2          Stage 3 Heat Span When set to 2 stage heat pump, this value sets the span for the 3rd stage heating.

SU = 10  Smart Upstage When the room temperature is far enough from the set temperature to call extra heating and cooling stages, the SMT‐770 will wait the minimum Su= value before bringing on extra stages. This delay provides time for the thermostat to determine whether additional stages are needed or if the current stages will bring the room to set point in a “reasonable” period of time.

dt= 30         Upstage delay time Time in minutes before next stage of heating or cooling is to be called. Delay only operates if stage trip temperature has not yet been reached. Adjustable between 10 ~ 90 Minutes in 5 minute steps.

oS = 0          Optimised Start/stop. (Adaptive Recovery) OS = 0 ‐ Optimised start/stop function Off. OS = 1 ‐ Optimised start/stop function running. (See page 42 for more information on this function)

C2 = 0.0      Calibration Remote Sensor

Calibration Offset for the TT terminal temperature sensor. Adjustable range +/‐ 4.5 deg C (+/‐9 F).

Co = 5 (41F) Cooling OFF temperature. ‐ See page 41 for more detail. Only operates if tt=OA and outside temperature sensor is fitted. Outside air temperature below this value will force the cooling function OFF. Adjustable between 0 ~37c. (32~98F).

Ho = 35 (95F) Heating OFF temperature. ‐ See page 41 for more detail. Only operates if tt=OA and outside temperature sensor is fitted. Outside air temperature above this value will force the heating function OFF. Adjustable between 0 ~37c. (32~98F).

HB = 37 (98F) High Balance Point. ‐ See page 40 for more information. tt=OA, the outside temperature sensor must be fitted and Sw 1=off. 2nd (or 3rd) stage heating is locked out when the outside air is above this temperature. Adjustable between 0 ~37c. (32~98F).

LB=‐9.5 (15f) Low Balance point. ‐ See page 40 for more information. tt = OA, the outside temperature sensor fitted, H3=EH, Sw 1=off and Sw2=on. Outside temperatures below this value will automatically select Emergency Heat mode. Adjustable between ‐9.5 ~25c. (15~77F).

Ft = off        Filter warning time Return air filter cleaning warning time. Adjustable between off and 900 hours.

Ad = 07       ModBus Address. See page 38 for more information. ModBus communications address

Bd = 9.6      ModBus Baud Rate Bd = 4.8 ‐ ModBus baud rate is 4,800 Baud. Bd = 9.6 ‐ ModBus baud rate is 9,600 Baud. Bd = 19.2 ‐ ModBus baud rate is 19,200 Baud.

Cd = 01       Commissioning Mode. See page 38 for more information. Cd = 0 ‐ Commissioning mode is OFF. Cd = 1 ‐ All time delays are off or reduced to a very small value.

SS = 0          Start Stop Mode Override (Typically used by ModBus Master) SS = 0 ‐ User Start Stop program in use SS = 1 ‐ Thermostat held in “Start” program typically via call from ModBus master. SS = 2 ‐ Thermostat held in “Stop” program typically via call from ModBus master.

OF                Override Function (Typically used by ModBus Master) OF=0 – The SMT‐770 will control its own relays (Default) OF=1 – The 5 SMT‐770 relays are being controlled via a ModBus master only. No buttons will function and all programming and control information is suppressed. The word “Override” will flash on the LCD during this mode. The SMT‐770 will automatically exit this mode if no valid ModBus signals have been received for 5 mins.

RS = 40       Thermostat sensor response time to room temperature changes. Adjustable from RS=10 (very fast) to RS=90 (very slow) Default is RS=40

tS = 0          Factory test mode ‐ See page 40 for more information. TS = 0 ‐ Factory test Mode OFF. TS = 1 ‐ Display configuration code.* TS = 2 ‐ Step cycle all relays in sequence, 1 2 3 4 5 etc. TS = 3 ‐ Reset software to factory default. Press Fan button to initiate. (* this table is available from the download section at www.thermostat.com.au)

Control logic

This  simple  diagram  (right)  provides a general insight into  the  control  logic  of  the  SMT‐770 thermostat. It attempts  to  describe  the  action of the DB=XX, the SP=XX  and  SD=XX  advanced  installer control capabilities in both two set point and single set point mode. By adjusting these three values to suit the  needs  of  the  user  or  equipment  extremely  tight  temperature  control  can  be  achieved, or a more energy efficient temperature control profile can be set.
In  single  set  point  mode  (sw8=off)  the  individual  heating  and  cooling  set  points  are  replaced by a “Dead Band” where the heating and cooling differential is controlled by a installer set value. This is the simplest method of temperature control.
Further,  you  are  able  to  adjust  how  quickly  the  SMT‐770  “Chameleon”  thermostat  responds to room temperature changes by adjusting the RS=XX value in the installer menu.  The  lower  this  setting  the  faster  the  thermostat  will  respond  to  room  temperature fluctuations, the larger this number the slower the thermostat will respond to changes in room temperature.

Commissioning

As with any thermostat, commissioning ensures that the thermostat and the equipment connected  to  it  are  operating  correctly  and  as  expected.  Although  the  SMT‐770  is  a  multifunctional thermostat, commissioning is quite a simple process. Follow the steps detailed  below  and  use  the  troubleshooting  guide  on  page  44  if  you  encounter  a  problem.
When the thermostat is fitted to the base plate and when 24VAC power is first applied, the LCD should briefly show all available segments (a LCD function test) then display the software version number before showing the time and operating mode etc. The SMT‐770 is fitted with a number of safety and energy saving time delays. If desired,
these  can  be  disabled  for  commissioning  purposes  by  entering  the  installer mode and setting the CD=00 value to read CD=01. After exiting the  installer  menu  you  will  note  a  “Spanner”  icon  flashing  on  the  LCD  to  remind  you  that commissioning mode is Active. After commissioning has been completed it is important  to  disable  commissioning  mode  by  entering  the  installer  menu  once  again  and setting the CD=01 value back to CD=00.
Note‐  when  in  commissioning  mode  ALL  time  delays  are  either  OFF  or  reduced to a extremely low value, it is therefore normal to potentially call for 3rd stage heating almost instantly 0.5deg below the heating set point.
If  you  choose  not  to  use  commissioning  mode  you  may  see  various  words  and  Icons  flashing in the LCD whenever a time period is in use. For example, the word “HEAT” may flash to indicate heating is required but being held off by the 4 minute anti‐cycle timer. Or the word “HEATING” may be flashing to indicate set point has been achieved however heating is being held ON by the minimum run timer.
The golden rule with the SMT‐770 is anything that flashes is a timer overriding what would normally be expected to occur; either a function is being held on or off momentarily. Please be patient.

Test fan operation.

With the thermostat OFF (tap the mode button to show OFF in the LCD). Simply tap the fan button to cycle through the available fan speeds. As the LCD changes to show the fan  speed  or  fan  mode  you  should  here  faint  “clicks”  as  the  SMT‐770  internal  relays  change, the equipment fan speed should change accordingly.

Test heating and cooling (if both fitted).
Turn the SMT‐770 to Auto season change mode by tapping the mode button until the words “Heat” and “Cool” are shown on the LCD.
Using the temp or Temp button set the desired temperature a few degrees below the  ambient  temperature.  After  a  few  moments  you  will  hear  a  click  and  the  word  “Heat” will change to “Heating”. Verify that the heating system is on and operating correctly. If stage 2 heat is being called the full stop “.” on the end of the word “MODE” will  be  seen  to  indicate  2nd  stage  heat.  Stage  3  of  heat  is  indicated  by  the  full  stop  flashing.
Using the temp + or Temp – button set the desired temperature a few degrees above the  ambient  temperature.  After  a  few  moments  you  will  hear  a  click  and  the  word  “Cool” will change to “Cooling”. Verify that the cooling system is on and operating correctly.  When  stage  2  cool  is  being  called,  the  full  stop  “.”  on  the  end  of  word  “MODE” mode will be seen to indicate 2nd stage cool.
Tap the mode button turn the SMT‐770 OFF. After any necessary timers have expired all heating, cooling and fan functions should stop. Verify that the system has shut down.
Note, in HP mode (SW2=ON) it is normal for the reversing valve to remain energised after the compressor has stopped. This is done to prevent “de‐compression HISS” and to limit the wear on the reversing valve. 30 minutes after the last reversing valve use it will de‐energise to conserve power.
If commissioning mode has been used it is important that the function be turned OFF before handover to the user.
Using  the  User  Manual  as  a  guide  set  the  real  time  clock  and  the  preferred  user  programme (if applicable). Explain equipment & thermostat operation to the user. Commissioning is complete.

Using Remote Temperature Sensors

Single  or  multiple  room  air  temperature  sensors can be connected to the SMT‐770 “TT”  terminals  if  temperature  averaging  over a larger area is desired. 4 examples of  commonly  used  sensor  configurations  are shown. Note ‐ Either TT=RS (remote sensor)  or  TT=Av  (Averaging  sensors)  value must be set in the advanced installer menu for these sensors to be used.
Please  note  the  configuration  of  RS‐01  &  RS‐02  sensors  in  the  examples  provided  above. Other sensor configurations are also available. A typical maximum of 40 meters is permitted for sensor runs with unshielded cable. If longer distances are required a larger diameter (0.3mm) shielded cable should be used.
When used in Start / Stop commercial programmable mode (SW6=on SW8=off), the afterhours run timer can be toggled on or off as required with a momentary press button on the remote sensor. See figure 17. As  the  SMT‐770  “Auto  detects”  sensors  connected  to  the  “TT” terminals, temperature sensors can also be switched on and off as required by placing a switch in the sensor wiring to open circuit the sensor loop. See figure 16.

Advanced Functions

ModBus Communications 
The  SMT‐770  has integrated  ModBus communications capabilities where,  using a  remote PC or building Direct Digital Control (DDC) system may view or adjust many of the SMT‐770 functions remotely.
It is not the scope of this manual to provide detail on the communication capability of the SMT‐770. Detailed ModBus communications detail is available for download from the download page at www.thermostat.com.au 
The communications port of he  SMT‐770  has  3  terminals used for communication.   “A”, “B” & “T”. Terminals “A+” & “B‐” are used for data communication, the terminal “T” ( a shared terminal from the thermostat T T input) is used as a Vss (screen ground to protect the integrity of the communication signal).

A  maximum of  32  SMT‐770s  can be connected to Any single hub.
Each SMT‐770 on the hub must have a unique network address (factory default is 7). These settings are adjustable from the advanced installer menu. See page 19 for more detail on setting the communications address.
A typical ModBus wiring example is given below. If using a common power supply to power all thermostats on a network, it is highly recommended that all thermostats power is wired in phase, i.e. “R” to “R” and “C” to “C” and NOT crossed.

In many cases where multiple thermostats are used in a single network or on a long network run the two DIP switched located between the “R” & “R/Com” terminals on the thermostat PCB should be switched on to improve network reliability. It is essential that the network be wired as a daisy chain as shown in fig 20. Fig  21  &  22  show examples of  how  NOT to wire a ModBus network.

Short communication runs, 1mm (18 gauge) twisted pair unshielded wire can be used,  however for longer runs or where electrical noise may be present twisted pair with shield should be used.

Factory Test Mode

The  SMT‐770  is fitted with a  simple factory  Test  Mode where you can confirm that all relays outputs functions and the current configuration of the thermostat.

• Ts = 0: Factory Test Function is OFF.
• Ts = 1: Display DIP switch configuration code.
• Ts = 2: Relay test mode. All relays cycle on then off in an endless loop.
• Ts = 3: Factory Software reset – Press Fan button to confirm.

High and Low balance points
The SMT‐770 is fitted with both High and Low Balance Point control capabilities.
For these functions to operate the Installer setting must be  TT=OA  (outside air temperature sensor fitted), the outside air sensor must be installed and SW1 must be OFF (Single fan speed mode).

High Balance point.
Set the installer menu value “HB=XX”.
When the outside air temperature is above this value, second or third stages of heating are held off regardless of the room and set temperature.
Set  this  function  is  designed  to  prevent  the  excessive  consumption of  energy  for  heating when the outside air temperature is warm.

Low Balance point
SW2=on, H3 =EH (Emergency Heat Mode) Set the installer menu value “LB=XX”. When the outside air temperature is below this value the SMT‐770  will automatically  switch to emergency heat mode when heating is required. If the outside temperature is above this LB=XX value the emergency heat mode can be selected manually at anytime with the “MODE” button.

Setting up the Heat & Cool Off functions
To conserve energy, the SMT‐770 can suspend the heating or cooling functions if the outside air temperature is within a prescribed installer set range. If the outside air temperature is above the HO=XX (heating OFF) value, heating will not be called regardless of the room and set temperature. If the outside air temperature is below the  CO=XX  value,  cooling will not be called regardless of the room and set temperature. “Heat” or “Cool” and the word “Locked” will flash on the LCD to show that these modes have been restricted.
Adaptive recovery
Only available in programmable mode (sw6=on).
The adaptive recovery function of the SMT‐770 permits the user to program a time that a desired set temperature is required, letting the thermostat calculate the most energy efficient time to turn on to achieve the desired temperature at the selected time.
If the user typically returns home at  5:00pm at the end of the work day,  setting program #3 (if used in residential programmable mode) to 5:00pm the SMT‐770 will calculate the most energy  efficient time based on the set and room temperatures as well as a history of temperature change to bring on the equipment prior to 5:00pm to meet the desired set temperature by 5:00pm. For example, when heating is required  the heating may start at 4.32pm so that the set temperature is reached at 5:00pm
Adaptive recovery may also prevent the SMT‐770 from running for a few moments just prior to a program change occurs.
“RECO” is shown in the LCD when ever Adaptive recovery is being used.

Specifications

• Input Voltage 24VAC 50/60 Hz +/‐ 15%.
• Relay rating 24VAC @ 1Amp maximum per relay.
• Operating Temperature 0‐50C (32 to 122F).
• Operating RH 0‐95% (non condensing).
• Storage Temperature 0‐65C (32 to 150F).
• Size 113 x 103 x 23mm.
• Display Size 74 x 55mm.
• Temperature Sensor(s) 10K NTC type 3.
• Accuracy +/‐ 0.3deg C @ 25 C. (77F)
• Stage Delays Minimum temperature change over time method.
• Timed upstage Delay 5~90 minutes.
• Anti‐cycle Delay Off to 4 minutes.
• Maximum hourly cycles Unlimited, 30, 10 or 6. (Installer set)
• Display resolution 0.5 deg C (1F).
• Control Range Off to 38c (100F).
• Outside Air temp display range 8 ~ +60c (1‐7 ~ 140F).
• Back light Blue EL.
• Backlight life 3,000 hours to half brightness.
• Adaptive recovery method Time to start vs temp differential method ‐ updating.
• Communications Protocol ModBus – contact Smart Temp for objects list.
• Fan speeds Based on difference between room and set temp.
• Approvals FCC (Part 15) (pending), C‐tick.
• Warranty 3 years RTB.

Sensor Reference Table

KΩ	24.3	22.0	20.0	18.1	16.2	14.3	13.7	12.5	11.4	10.4	10.0	9.57	8.75	8.05
C	6	8	10	12	14	16	18	20	22	24	25	26	28	30
F	42.8	46.4	50	53.6	57.2	60.8	64.4	68	71.6	75.2	77	78.8	82.4	86

Troubleshooting

Symptom	Suspected Fault	Suggested remedy
Temperature display seems inaccurate	Air from the wall cavity may be leaking into the rear of the thermostat / sensor enclosure.	Plug holes in wall with tape to prevent leaks
	The internally fitted temperature sensor is folded back inside the Chameleon and not being exposed to the room air temperature.	Carefully move the room temperature sensor bead so that it is just behind the sensor opening in the case.
	External heat or cool source such as lamps, televisions or drafts from open doors affecting the accuracy of sensor.	Move lamps, vents or other sources of abnormal temperature away from sensors
	Sensor calibration may setting are incorrect	Adjust C1=XX value in installer mode to correct perceived sensor inaccuracy. Page19
“Locked” appears on LCD and heating or cooling will not operate.	This is not a fault. Outside air temp to high to require heating Outside air temp to low to require cooling.	The Ho=XX &/or Co=XX value is inhibiting heating or cooling calls. Change these values in the installer menu, details on page 19.
Heating or cooling runs in dead band.	SMT‐770 incorrectly set to HP mode. (SMT‐770 keeps reversing valve energised after heating / cooling has stopped to limit decompression noise from AC system.)	Set SW2=OFF and retest heating & cooling operation.
	Minimum run period has not yet expired. Words “Heating” or “Cooling flash in the LCD	Sw7 sets minimum run period from 2 or 6 minutes.
	Compressor and reversing valve wiring crossed in HP mode (sw2=on)	Check W1 & Y1, Y2 for correct connections.
SMT‐770 has no display	Power failure or faulty SMT‐770	Check for 24VAC on the 24 & 24C terminals
Reversing valve remains energised after heating or cooling has stopped.	This is not a fault	The reversing valve remains energised after the heating/cooling has stopped to limit de‐ compression hiss. Reversing valve will de‐ energise within 2 hours of the last call.
Spanner Symbol flashes on LCD	This is not a fault Commissioning mode enabled.	Exit commissioning mode before handover to user. See page 21
E.Heat or E.Heating is shown on LCD without manually selecting it.	This is not a fault.	LBP reached, outside air too cold for reliable HP operation. Set LBP with the LB=XX value in the installer menu, details on page 19

Symptom	Suspected Fault	Suggested remedy
The word OFF is flashing in the LCD. Mode button has no effect.	This is not a fault	TT=Of in advanced installer menu.
Some buttons do not appear to operate. Padlock is show on LCD.	Key board lock is on.	LC=XX value in advanced installer mode set the lock values, see page 19.
Cannot enter heat or cool modes	SMT‐770 thermostat set for Heating or cooling only modes	Heating or cooling mode not available on your air conditioning system
Cannot set heating and cooling to desired value. Padlock symbol flashes	This is not a fault.	HL=XX (heating set point limit) and CL=XX (cooling set point limit) restrict control range. See page 19 for more detail.
Outside Air Temp display is showing dashes	Outside air temperature air sensor has failed.	Check wiring and outside air sensor. Replace outside air sensor
	No outside air sensor fitted.	Change TT=AO to TT=RS in advanced installer menu.
“Heat” or “Cool” is flashing in the LCD. Heating or cooling has not started.	This is not a fault. Heating or cooling will start shortly.	Anti cycle delay in progress. This can be disabled if required for commissioning. See page 21.
The Fan runs on for some time after the heating or cooling stops, even when I turn the SMT‐770 OFF.	This is not a fault.	The fan purge mode is set. FP=XX value
SMT‐770 displays wrong mode (C or F).	The SMT‐770 can operate in both Deg C and Deg F mode as set in installer menu.	See page 19 for changing the CF=XX value
Cannot select multiple fan speeds	SMT‐700 set for single fan speed Sw=OFF	Turn SW1 to ON. NOTE, 3 fan speed mode can only be used on single stage systems.

Email ‐ [email protected]
Web ‐ www.smarttemp.com.au
Phone +61 3 9763 0094
Fax + 61 3 9763 0098

Email ‐ [email protected]
Web ‐ www.smarttemp.com.au
Phone +61 3 9763 0094
Fax + 61 3 9763 0098

This product has been manufactured by Smart Temp Australia. Intellectual rights apply ‐ all rights reserved.
This product is Patent Pending.

REFERENCE:

DOWNLOAD MANUALS:

Smarttemp SMT‐770 Programmable Thermostat Installer Manual

OTHER MANUALS:

Smarttemp SMT‐770 Programmable Thermostat Owner Manual

Smarttemp SMT‐770 Residential Thermostat PRODUCT SPECIFICATION GUIDE

Smarttemp SMT‐770 Programmable Thermostat Installer Manual