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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