Lightstat TME series User manual

INSTALLATION & OPERATION
MANUAL
Model TME-____________________*
* Balance of model number is determined by
customer specied limits and Setbacks.
AUTOMATIC SETBACK THERMOSTAT
LIGHT SENSING OR CONTACT CLOSURE
FOR LOW VOLTAGE (24VAC) SYSTEMS ONLY
REQUIRES A COMMON WIRE
Manufactured by:
LIGHTSTAT INC.
BARKHAMSTED, CT
[phone]
www.lightstat.com

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CONGRATULATIONS on your purchase of a Lightstat TME. It represents
reliable, modern, electronic tempe rature control in addition to unique energy
saving features.
Features
• 1 Amp relay switching of up to 6 HVAC loads.
• Automatic Changeover from Heating to Cooling with a 5º F deadband
between heating and cooling to prevent short cycling of equipment.
• Automatic Setback of temperatures based on light sensitivity or contact
closure (model dependent).
• System ON/OFF switch, and Fan switch for AUTO or ON fan operation.
• PRE-CONDITION feature to pre-heat or pre-cool the building prior to
occupancy at the start of the day.
• Fan control settings for Heating to allow either thermostat controlled fan
(typical of electric heat) or a limit switch controlled fan (typical of gas heat).
• Auxiliary output options to permit the O/B output to be active with a call for
Heat or Cool; for heat pump reversing valve.
• A1-A2 isolated dry contact outputs for night shutdown of dampers or
equipment.
• Connections for using a Remote Room Sensor.
• Connections for using a Supply Air Sensor.
• Light Sensitivity adjustment to permit operation in bright or dim areas (model
dependent).
• Stages of Heat and Cool stagger ON.
• Proportional plus Integral control for accurate, even temperature control.
• Factory set temperature limits to prevent overheating and overcooling.
• Minimum ON and OFF time delays for compressor protection.
• Field Check button to cancel time delays for checkout in the eld.
• Fan harvests energy from coils.
• Occupancy of less than two hours will not affect pre-conditioning timing.
• Random restart after Setback or power failure.
• RTU visible alarm.

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Do not attempt to use directly with Line Voltage (120 VAC or higher),
DC (Direct Current), millivolt (thermopile), or proportional control
systems. A transformer and relays must be used to interface with
these types of systems. The Lightstat TME is designed for 24 VAC
systems only.
Pick a mounting location AWAY from drafts, windows, doors,
outside walls, and heat vents. Relocate if necessary.
The Lightstat TME senses a change in LIGHT LEVEL to determine
Setback. Mount it under lights that GO OFF when people GO
HOME. Locate the Lightstat TME at least 10 feet from a night light.

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Description
A - Current temperature.
B - Indicates if SUPPLY, REMOTE, or ROOM temperature is being displayed.
C - Setback indicator light. Glows green during Setback.
D - Visual Alarm light. Flashes red during a Roof Top Alarm signal.
E - Toggles temperature display between ROOM and SUPPLY air.
F - Temperature adjustment buttons.
G - System power button.
H - Fan ON/AUTO button.
I - Fan ON/AUTO Indicator.
J - Light Sensitivity Adjustment.
K - Illuminated ON and arrow (◄) indicate which outputs are currently ON.
Flashing arrow indicates time delay.
L - Flashing DELAY indicates the stages are held ON or OFF by a time delay.
M - Press Check button to cancel any active time delay(s).
N - Indicates temperature setpoints. Standard 5º dead-band between heat and
cool setpoints.
O - Flashes to indicate cool setpoint is at the minimum temperature limit.
P - Flashes to indicate heat setpoint is at the maximum temperature limit.

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CAUTION: Disconnect power supply before beginning installation.
Remove the old thermostat from the wall taking note of the wire colors on the
back of the mounting kit provided. Thread the thermostat cable through the hole
on the back of the Lightstat TME. Mount the Lightstat TME securely to the wall
using the hardware provided. The Lightstat TME should be leveled for cosmetic
reasons.
Connecting the Outputs
R - Hot Wire; one side of control (24-30VAC) transformer. If two hot wires are
present (as with RC and RH) determine if they come from separate transformers.
The Lightstat TME must be installed on a single transformer system.
C - Common or Neutral side of transformer. This must be connected.
O/B - This output may be active with either a call for Heat (B) or a call for Cool
(O) but not both. It is typically used for a heat pump reversing valve.
Y1 - First Stage of Cooling. There is a 1º(F) differential between any two stages
of Heating or Cooling.
Y2 - Second stage of Cooling.
W1 - First stage of Heating.
W2 - Second stage of Heat or Auxiliary heat with heat pumps.
G - Air Circulating fan. The Lightstat TME will control the fan during the cooling
cycle. Fan operation during the Heating cycle depends on the setting of switch
#4 on page 15. The Lightstat TME allows for either constant ON operation of the
fan or AUTO operation. The fan reverts to AUTO in Setback.

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System Layout
The Lightstat TME is used as a stand-alone thermostat to control a single HVAC
system. Do not attempt to control more than one HVAC unit with a Lightstat
TME.
You can add a Remote Room Sensor to sense temperature remotely.
Two Averaging Remote Room Sensors may be used to provide an average
Room Temperature (Order as Averaging Sensors).
And you can add a Supply Air Sensor to check temperature of the air coming
from your HVAC system.
Note: All wiring should be minimum #18 AWG. Shielding is not required.

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This is a eld option. You might not use this option with your Lightstat TME. You
may add this in the eld to an existing Lightstat TME.
Mount the Remote Room Sensor on the wall 5’ to 7’ off the oor, in the area to be
controlled.
Use #18 gauge 2-conductor twisted pair cable between the Lightstat TME and the
Remote Room Sensor. Remote Room Sensors are unaffected by wire runs of up
to 500 feet.
Remote Room Sensor cables do not have polarity, either wire may be connected
to either terminal. Cables do not need to be shielded.
At the Lightstat TME end connect the 2-conductor cable to the two terminals
marked Remote Room Sensor.
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
When using a Remote Room Sensor make sure the Remote Room Sensor
switch (#5) on the inside of the Lightstat TME is set to ON. The word REMOTE
will appear in the display.

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This is a eld option. You might not use this with your Lightstat TME. You may
add this in the eld to an existing Lightstat TME.
Mount the Supply Air Sensor on the supply air duct securely with the probe
horizontal or downward.
Use #18 gauge 2-conductor twisted pair cable between the Lightstat TME and
the Supply Air Sensor. Supply Air Sensor is unaffected by wire runs of up to 500
feet.
Supply Air Sensor cables do not have polarity, either wire may be connected to
either terminal. Cables do not have to be shielded.
At the Lightstat TME end connect the 2-conductor cable to the two terminals
marked Remote Supply Sensor on the thermostat. At the Supply Air Sensor
end connect the two conductor cables to the wires on the Supply Air Sensor.

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Use #18 gauge 2-conductor twisted pair cable between the Lightstat TME and
the damper or equipment to be shut down.
A1-A2 cable does not have polarity, either wire may be connected to either
terminal. Cables do not have to be shielded.
At the Lightstat TME end connect the cable to the two terminals marked A1 and
A2. At the other end, connect it to the damper or equipment.
The A1 and A2 terminals are an isolated set of dry contacts rated at 2 amps (24-
30VAC).
They are typically OPEN during the occupied period and CLOSED during
Setback. They will OPEN during the pre-condition period.
Setting the Heat Pump / Conventional Switch (#1)

Non Lightstat Automatic Lighting Control Connections
Use #18 gauge 2-conductor twisted pair cable between the Lightstat TME and
the customer supplied switch or alternate closed contact.
C1- C2 cable does not have polarity, either wire may be connected to either
terminal. Cables do not have to be shielded.
At the Lightstat TME end connect the cable to the two terminals marked C1
and C2. At the other end connect it to the customer supplied switch or alternate
closed contact.
The C1 and C2 terminals are contact closure terminals and should not be
connected to any power.
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The Lightstat TME has a visual alarm to indicate that there is a problem with the
Roof Top Unit (RTU). This is a eld option. You might not have this option with
your specic RTU.
Use #18 gauge 2-conductor cable between the Lightstat TME and the RTU. The
alarm is unaffected by wire runs of up to 1000 feet.
If the alert does not function correctly, verify proper installation of wiring
and jumper.

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Setting the Heat Pump / Conventional Switch (#1)
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings. Moving this switch to the ON position will increase the
heating Setback by 5° (F). This will allow a heat pump to stay in a compressor
mode longer and avoid expensive electric resistance heat.
Note: When connecting a Lightstat TME to a heat pump with Thermostat
Reversing Valve Control you will need to install a jumper wire between W1 and
Y1 at the Lightstat TME as shown in the diagram above.
Note: When connecting a Lightstat TME to a heat pump with Unit Reversing
Valve Control no jumper wire is required as the reversing valve is positioned by
the unit internal controls based on whether cooling or heating is being called by
Y1, Y2 or W1, W2.

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Setting the Compressor Time Delay Switch (#2)
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
When this switch is set to OFF, the minimum On and Off time for any stage of
Heating or Cooling will be 3 minutes.
When set to ON, there will be no minimum On and Off time for any stage of
Heating or Cooling.
In either position, the Fan will continue to run for 45 seconds after the Heating
or Cooling stops; unless the Fan switch is set to ON, in which case the fan runs
continuously.
During Setback the Fan will revert to the Auto Mode.

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Setting the O/B (Aux) Switch (#3)
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
The position of the O/B switch will determine whether the O/B output comes on
with a call for Heating or for Cooling.
In the OFF position it will remain latched On during the Cooling Cycles (O) until
there is a call for Heating.
In the ON position it will remain latched On during the Heating Cycles (B) until
there is a call for Cooling.

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Setting the Heat Fan Switch “Gas/Electric” (#4)
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
This is often called the “Gas/Electric” switch. Consult the HVAC equipment
manufacturer instructions for details on how to set this switch.
When controlling fossil fueled equipment with a fan limit control you may want to
set this switch to the On position.
Note: The Lightstat TME will not bring on the fan in this setting during the heat
cycle.
Leave this switch set to Off for all other equipment.

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Setting the Remote Room Sensor Switch (#5)
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
This will tell the Lightstat TME to ignore the on-board temperature sensor.
You will see the word REMOTE appear in the display indicating the Remote
Room Sensor switch has been moved to ON.
A “00” in the display indicates no remote sensor is connected.
A “99” in the display indicates there is a short (the two wires are touching) in the
Remote Room Sensor wiring.

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Setting the Pre-Condition Countdown
Your Lightstat TME has the ability to come on before the lights do.
Note: The Lightstat TME must be powered Off and On in order to “read” a
change of switch settings.
Set the dial for the number of hours that the lights in the facility will be off when it
is closed, and the Lightstat TME will automatically come on early enough to bring
up the heat or cool down before occupancy.
Choose the number of hours the facility is unoccupied from the top list. Set the
dial to the corresponding character from the lower list.
The Lightstat TME looks at how long the time is before occupancy and how far
away from the heating and cooling setpoints the temperature is. It calculates how
long it will take to heat up or cool down, and operates the equipment accordingly.
Remember to count the total average time of darkness expected during
unoccupied times. If all the days do not have the same length of darkness,
choose the period used for most days of the week. The Lightstat TME can only
remember one schedule.
For example, if your facility is occupied from 8:30 AM to 9:30 PM from Monday to
Saturday but only open a few hours on Sunday; choose 11 hours and set the dial
to “B”.
The Lightstat TME will go back into Setback if the lights remain off after the Pre-
Condition period. Thus, if a facility is closed on Sunday, the Lightstat TME will go
back into Setback and pre-condition for Monday.

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Powering Up the Lightstat TME
First you must turn on the breaker or switch that feeds power to your
Lightstat TME.
Next press the System On/Off button, if necessary, to turn on the Lightstat TME.
The power-up sequence will give you information on your Lightstat TME.
Sequence Display Symbol Meaning
First All Characters On Veries all display characters
Second Cool Set Factory Min Cool Setting
Heat Set Factory Max Heat Setting
Temperature --
Third Cool Set Factory Cooling Setback
Heat Set Factory Heating Setback
Temperature Pre-Condition Period
Fourth Cool Set --
Heat Set --
Temperature Max Pre-Condition Period
Fifth Cool Set Software Revision #
Heat Set Software Revision #
Temperature --

Determining Your Lightstat TME Setback Control
If your Lightstat TME has a clear window then go to Adjusting the Light
Sensitivity below.
If your Lightstat TME does not have a clear window, then it will not respond to
light changes. It is most likely controlled by the Lightstat TME Automatic Lighting
Control (ALC), customer supplied switch or alternate contact closure. No action
is required.
Adjusting the Light Sensitivity
You will want to make sure the Lightstat TME sets back temperatures when the
lights are turned down in the room where the Lightstat TME is located.
The clear plastic window on the top of your Lightstat TME is where it senses the
light. If you shadow the window at the top of the Lightstat TME, it will cause it to
shift to the Setback mode. It will signal this by turning on the GREEN SETBACK
LIGHT. When the Setback light is on, the Cool Set and Heat Set temperatures
will show the Setback temperatures, which are model specic and not adjustable.
You will make the Lightstat TME go into Setback mode more easily by moving
the LIGHT SENSITIVITY ADJUSTMENT slide to the right, toward BRIGHT.
If the Lightstat TME goes into Setback mode when the room is occupied, you
can make it less sensitive by moving the LIGHT SENSITIVITY ADJUSTMENT
slide to the left, toward DIM.
Turn off the lights in the room around the Lightstat TME and make sure that the
GREEN SETBACK LIGHT comes on.
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Using the Lightstat TME
Use the SYSTEM ON/OFF button to turn your HVAC equipment On and Off.
Use the DISPLAY button to shift the temperature display from ROOM
temperature to SUPPLY temperature. The SUPPLY temperature is the air
temperature coming from your HVAC system. You will have to install a Supply Air
Sensor in order to read this temperature. If you do not have this sensor installed,
then the display will read “00”.