Lightstat Installation and Operation Manual
TG Series Thermostats for Heat/Cool Applications
24 Volt A.C. Power Robbing, Temperature Limiting Thermostat with
Optional Automatic Temperature Setback
No Common Wire Needed.
Read instructions carefully before attempting to install, operate or service the Lightstat
electronic setback thermostat. Failure to comply with instructions could result in personal
injury and/or property damage. Retain instructions for future reference.
Description
The Lightstat thermostat saves energy and
operating costs by using Owner specied factory
limited temperature ranges which prevent excessive
use of heating or cooling equipment. These limits
cannot be changed by the user. The unit requires no
batteries and no programming or reset in the event of
a power failure. Optionally, the Lightstat thermostat
can set back the temperature based on light level in
the space. A dark space is considered unoccupied
and will turn the heating and cooling setpoints back
for better savings.
Thermostats described are available in Heat/Cool
(TGHC) and Heat Pump (TGHP) models.
Specications
Construction.............................Electronic (solid state)
Electrical Requirements............24-30 VAC
Anti-Cycle Time Delay...............45 seconds ON and OFF
Switching Current.......................0.2 to 1.0 AMP (max) per output
Heating Temperature control range (typical)............55°F to 78°F (on models with heating)
Cooling Temperature control range (typical)...........85°F to 70°F (on models with cooling)
Operating temperature differential minimum 0.5°F
Dimensions 3.6”W x 5.0”H x 1.3”D
Weight 8.0 oz
Function switches: Cool/Off/Heat & Fan On/Auto
Warning:
Read these instructions carefully! Failure to follow them could cause damage to the product or
cause a hazardous condition.
General Safety Information:
Do not use this product on circuits exceeding 30 VAC. Higher voltage will damage this control
and could cause electrical shock or personal injury.
1. Installer must be a trained, experienced service technician familiar with the system this
product will control.
2. Disconnect all power before beginning installation to prevent electrical shock or
equipment damage.
3. Control voltage and current ratings must fall within the range outlined in
“specications.”
4. Verify that the relay load does not exceed 1 amp. Excessive load will damage the solid
state switch.
Thermostat Placement:
Mount your thermostat vertically about 5 feet above the oor in an area that has good air
circulation at average room temperature. Be sure to locate the thermostat where it will be
exposed to lights that are normally on when the room is occupied.
Locate the thermostat away from:
• Outside walls and drafts
• Doors, windows, and direct sunlight
• Supply air ducts, radiators and convectors
• Applicances that produce heat or cool air
2
Warning: Do not use this thermostat on circuits exceeding 30 volts AC.
Installation:
1. Check the equipment ratings on the system this thermostat will control, to make sure
the thermostat is appropriate for the application.
2. Check the system voltage and verify it is between 24 and 30 VAC.
3. Turn the sytem power OFF before you begin the installation procedure.
4. Note the color of the wires and the terminals they are connected to. Some thermostats
may have to be removed from the wall to determine wiring connections.
5. Remove the old thermostat from the wall, making sure the wires do not fall back into the
wall.
6. Make sure the thermostat switch is in the OFF position.
NOTE: TGHP thermostats may have power even while switch is in the OFF
position. (if the display can be read with the switch in the off position, the
thermostat has power)
7. Set DIP switches (see page 7).
8. Attach the wires as shown in the model specic wiring diagrams (see page 6).
9. Attach the thermostat to the wall using the hardware supplied. Note: The thermostat
does not have to be level in order to operate properly, but it should be level for good
appearance.
10. Turn the system power ON and the thermostat switch to the ON position as desired.
Note: Your Lightstat may come from the factory with xed light sensitivity. This means that under normal lighting,
the thermostat will heat/cool your space to the comfort slide setting. Under low light conditions, the thermostat will
set the temperature back. A green setback light turns ON, indicating the thermostat is in the Setback mode.
Adjusting (optional) light sensor:
1. Open the thermostat cover and locate
the green setback light at the upper right
of the thermostat and the light sensor
below it.
2. Cover the light sensor with your
nger. The green setback light should
turn ON after 3 seconds, indicating the
thermostat is in Setback mode. Remove
your nger and the green light should
turn OFF indicating the thermostat is in
Day mode.
3. The Light Sensitivity knob located at
the lower right of the thermostat
controls the amount of light necessary
to keep the thermostat in the Day mode.
4. Turn the knob full clockwise (towards
bright) to put the thermostat in the
Setback mode. The green light should be on after 3 seconds.
5. Now slowly turn the knob counterclockwise (towards dim) until the green setback light
just goes out.
6. Close the thermostat cover. Cover the light sensor and verify the green light turns on.
Remove the covering over the sensor and verify the green setback light turns off. If it
does not turn off, slightly adjust the light sensitivity knob clockwise and re-verify
operation. Your thermostat is now adjusted to your current light level.
3
Adjusting (optional) night setback setting:
Your Lightstat may come from the factory with a xed night setback. That means when your
Lightstat thermostat is in the Setback mode, it will automatically set the heating/cooling back
a predetermined number of degrees from the comfort slide setting. If your model has setback
options, there will be a night setback switch on the back or in the lower right hand corner of
the thermostat. Choosing less setback may be more comfortable, but will offer less energy
conservation and savings. See page 11 for more detail on DIP switch settings and setback
features.
Note: When the green setback light goes on, the display will briey ash showing the night
setback temperature. When the green setback light turns off, the display will ash showing the
comfort slide setting temperature.
Some thermostats may be equipped with a “slide sensitive” setback. (refer to model specic features to know if your thermostat has this functionality). If the temperature slide is not
moved for an amount of time specied by the customer (and preprogrammed at the factory),
then the thermostat is in setback. To bring the thermostat out of setback, simpley move the
temperature slide.
Note: Typically, moving the temperature slide will show the current thermostat setpoint. For
slide sensitive setback models, the setback setpoint cannot be viewed on the dsiplay because
touching the slide will bring the thermostat out of setback.
Adjusting the temperature setting:
Flashing dot indicates time delay
Note: There is a minimum run time of 45 seconds once
the heating/cooling turns on to prevent short cycling. Once
the heating/cooling turns off, it will remain off for at least
45 seconds.
Indicates a call for Heat or Cool
Note: Any time the comfort slide is moved, the display will illuminate and the ashing
number indicates the current setpoint temperature.
1. Make sure the system power is ON.
2. Move the thermostat power switch to the ON position.
3. Adjust the comfort slide either up or down until the ashing number reaches the desired
setting.
4. Once you have stopped moving the comfort slide the display will change from a ashing
display to a steady display. A steady display indicates actual room temperature.
5. A steady dot in the upper right corner of the display will indicate if heating/cooling
system is ON.
4
Basic Operation:
• Steady temperature display indicates actual room temperature.
• Set temperature with comfort slide.
• Display will illuminate briey when temperature slide is moved.
• Flashing display indicates comfort slide setting.
• Solid dot in upper right corner of display indicates a call for heat or cool.
• Flashing dot in middle of display indicates that a time delay is in effect.
• Temperature range and setbacks are programmed at the factory.
• Night setback is automatic when there is a drop in the room light level.
• Setback mode is indicated by a green light.
Check the inside cover for your model’s temperature range and setback.
Application Notes:
When connecting the TG series (power robbing) thermostats to a furnace control board or
electronic ignition model, one of (3) potential issues may occur.
1. When not calling for heat, the furnace falsely starts its heating cycle.
2. When calling for heat, the furnace is “chattering” or does not complete its heat cycle.
3. The display goes blank at times.
If the installation exhibits any of these issues, we recommend that you add a 200 ohm
(minimimum 20 watt) resistor from any output terminal to the C (common) terminal at the front
of the furnace control board, ignition module, or zone control valve.
Below is a wiring diagram showing a resistor placed from the W (heating) terminal to C
(Common). Other terminals may be used.
It is recommended that the resistor be mounted so that it is not touching anything and that
there is adequate ventilation around it as it will normally get warm. A 200 Ohm, 20 Watt
resistor is included with a metal lead from one end and a white wire whip from the other to
allow exibility during installation. The resistor has no polarity.
5
Thermostat Layout
TGHC Heating/
Cooling Thermostat Specications:
The TGHC is a single stage heat/cool thermostat.
This thermostat cannot be used on:
1. Millivolt systems (self generating systems
that do not have a transformer or relay).
2. Two transformer systems using RC and
RH wires.
3. Heat pump systems.
4. Line voltage (120 VAC) systems directly.
TGHC Wiring Diagram
TGHP Heat Pump Thermostat
Specications:
The TGHP is a single stage heat/cool
thermostat for heat pump applications.
This thermostat cannot be used on:
1. Millivolt systems (self generating systems
that do not have a transformer or relay).
2. Two transformer systems using RC and
RH wires.
3. DC voltage systems.
4. Line voltage (120 VAC) systems directly.
Note: TGHP models do not have
lock on/lock off timers for backup heating.
Operation is strictly temperature dependent.
Note: This model may be powered at all
times even when the switch is in the “OFF”
postion. (model dependent feature)
TGHP Wiring Diagram
Warning:
Never connect a common or
neutral wire to the Lightstat.
This will cause damage to the
Lightstat.
6
Setting the DIP switches:
Your thermostat may have up to (7) congurable DIP switches depending on the
features specied for your application. DIP switches may be congured in accordance with
the following table.
For TGHC Models, switch positions 1 through 5 should be set. Positions 6 and 7 have no
function.
For TGHP Models, all switch positions (1 through 7) should be set accordingly.
Position Off (left position) On (right position)
1 Fahrenheit Celsius
2 45 Second Lockon/lockoff
Timers Active
3 Lesser setback number Greater setback number
4 Fan controlled by thermostat
in heat mode.
5 Fan locked in auto when in
setback.
6 Backup Heat
Operating Differential
1.5 ° F
(0.8 ° C)
7 O output with cool O output with heat
Note: If any DIP switch is changed during operation, the thermostat will reset and the new
dipswitch setting(s) will be read.
45 Second Lockon/lockoff
Timers Inactive
Fan controlled by external
device in heat mode.
Fan on allowed when in set-
back.
Backup Heat
Operating Differential
3.0 ° F
(1.7 ° C)
7
Troubleshooting your Lightstat thermostat:
PROBLEM POSSIBLE CAUSE SOLUTION
The digital display does not
light up.
The display works but the
heat does not come on.
The display works but the
cooling does not come on.
(some stats are heating only
and this would not apply).
Setback indicator stays ON or
OFF.
Fan runs continuously with
thermostat system switch set
to OFF.
Control relay on heating unit
chatters.
1. No power to the stat or system equipment.
2. Lightstat switch in OFF
position.
The room temperature
is above the factory programmed limit of the thermostat.
The room temperature is
below the factory programmed
limit of the thermostat.
1. Improper light sensor
adjustment.
2. Thermostat location is not
optimal.
Fan switch set to the ON
position.
Low voltage
1. Check the system low
voltage power.
2. Check the system ON/OFF
switch.
3. Check the circuit breaker.
Check again when the room
temperature falls below the
factory programmed limit.
Check again when the room
temperture goes above the
factory programmed limit.
1. Adjust light sensor
(optional)
2. Move thermostat if
necessary.
Review locations to avoid
(page 2).
Move fan switch to the AUTO/
OFF position.
8
Warranty
Lightstat Inc. warrants each product manufactured by it to be free from defects in
workmanship under normal use and service; its obligation under this warranty, at its option,
being limited to repair or replace the product if found defective, provided that it is removed by
the installer and returned within (12) twelve months of purchase to the factory with transportation charges, if any, prepaid after rst obtaining return authorization and shipping instructions
from Lightstat Inc.
This warranty is expressly in lieu of other warranties expressed or implied including a warranty
of merchantability and of all other obligations or liabilities on its part.
The company neither assumes nor authorizes any other person or organization, other than the
seller, to assume for us any other liability in connection with this product. This warranty shall
not apply to any product which has been subject to misuse, negligence, or accident, nor to any
product which has not been operated in accordance with the printed instructions. The
company shall not in any event be liable for any consequential damages, secondary charges,
expenses of installing or disconnecting, injury or damage resulting from an alleged defect in the
unit.
Some states do not allow the exclusion or limitation of implied warranties or consequential
damages, so that above limitations or exclusions may not apply to you. This warranty gives
you specic legal rights, and you may also have other rights that vary from state to state.
Manufactured by:
Lightstat Inc.
22 W. West Hill Road
Pleasant Valley, CT 06063
860-738-4111 or fax 860-738-4123
Made in the USA.
I-17
Rev 6/4/2011
9
Loading...