Quest Controls 100 T-Stat LLC User manual

Rev 3.2, 04/10/18
Model 100 T-Stat LLC
User’s Manual
COPYRIGHT NOTICE
Copyright © 2018 by Quest Controls Inc. (QUEST).
The material discussed in this publication is the proprietary property of QUEST.
QUEST retains all rights to reproduction and distribution of this publication.
Specifications are subject to change without notice.

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Table of Contents
AT&T “Ask Yourself” Principles and Philosophy ...........................................................................................3
1.0 Overview .................................................................................................................................................4
1.2 Features and Benefits .........................................................................................................................4
2.0 Installation / Wiring ................................................................................................................................4
2.1 Installing the mounting plate..............................................................................................................5
2.2 Wiring..................................................................................................................................................5
3.0 Front Panel Display/Keypad Operation ..................................................................................................7
3.1 Run Mode............................................................................................................................................7
3.2 Occupied Override ..............................................................................................................................7
3.3 Lead Switch .........................................................................................................................................7
3.4 T-Stat Settings .....................................................................................................................................8
4.0 Care and Cleaning ...............................................................................................................................8
5.0 Troubleshooting......................................................................................................................................9
Table of figures
Figure 1 –Back Plate Mounting .................................................................................................................... 4
Figure 2 - Connection Descriptions...............................................................................................................5
Figure 3 –Typical Wiring Diagram ................................................................................................................6

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AT&T “Ask Yourself” Principles and Philosophy
“Ask Yourself” principles are presented in the form of questions. Listed in the table
below are the ten “Ask Yourself” questions that you should be able to confidently
answer “yes” to before you undertake any task related to the network. If you are unable
to answer “yes” to any of the ten questions, please stop and resolve the issues before
resuming your work. Protecting the network is everyone’s responsibility.
THE TEN “ASK YOURSELF” PRINCIPLES:
1. Do I have the proper access and appropriate login credentials for the work I
am about to do?
2. Do I know why I'm doing this work?
3. Have I identified and notified all key stakeholders who will be directly and
possibly indirectly affected by this work?
4. Can I prevent or control service interruption or defect introduction?
5. Is this the right time to do this work?
6. Am I trained and qualified to do this work?
7. Is all relevant documentation for this work complete, current and error-free?
8. Do I have everything I need to quickly and safely restore service if something
goes wrong?
9. Have I walked through the entire process or procedure I am about to follow?
10.Have I verified/validated that I have completed all the steps in the process or
procedure, obtained proper closure and notified appropriate technology
centers, as applicable?

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1.0 Overview
The Quest Controls Lead/Lag control thermostat is designed for controlling two single stage HVAC
systems. It is an easy to use thermostat for remote shelters that require a simple to use lead/lag
controller with a wide profile operating range for cooling.
1.2 Features and Benefits
•Controls two single-stage HVAC systems for Fan, Cool and Heat.
•Powered from the HVAC 24VAC transformers.
•Automatic lead change every 24 hours.
•LCD display for current operating mode and shelter temperature readings.
•Comfort mode to allow “Occupied” settings for a one hour timed duration.
•Five button keypad for navigation to other status screens.
•Built in zone temperature.
•All configurations and setpoints are stored in non-volatile flash memory and are not field
changeable.
2.0 Installation / Wiring
The T-Stat LLC is a simple application specific controller designed to control two Single -Stage
Conventional HVAC systems.
1-1/16"
1-1/2" 2-1/4"
3-1/4"
Back mounting plate 5-3/8", 5-1/2" with cover
Back mounting plate 3-5/8", 3-7/8" with cover
1-9/16"
1/2"
UP
Figure 1 –Back Plate Mounting

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2.1 Installing the mounting plate
1. Plan the Location –The T-Stat should be mounted away from external sources of heat or cold
(doors, HVAC supply grill, exhaust from equipment, radio heads, etc.) and provide a good
representation of the shelter’s temperature.
2. Prepare the Area - The mounting screw holes will line up on a standard duplex outlet box or can
be flush mounted to the wall. When flush mounting, ensure clearance for the wires to exit
through the center window on the back plate. Install outlet box or screw anchors and run
thermostat wires.
3. Remove the cover - The cover of the T-Stat is held on by four clips, two on the top and two on
the bottom. Remove the cover carefully, the cover may be snug and depressing the clips
through the slot openings may help in getting the cover off.
4. Mount the Plate - Dress the wires through the center window on the back plate and install
mounting screws. Tighten screws to ensure the plate is mounted securely, but do not over
tighten and warp the back plate.
2.2 Wiring
1. Terminate the Wire Connections –Cut off excess wire, dress wire flush to the back panel and
strip 1/4” of insulation to expose conductor. Insert and tighten using the Wire Terminations
diagram. Label all point to point connections at both ends of the cable.
2. Connection Descriptions:
Terminal
Description –wire color
HVAC 1 - R
24VAC power - red
HVAC 1 - C
24VAC common - black
HVAC 1 - G
Fan Control –green
HVAC 1 - Y
Call for Cool - yellow
HVAC 1 - W
Call for Heat - white
HVAC 2 - R
24VAC power - red
HVAC 2 - C
24VAC common - black
HVAC 2 - G
Fan Control –green
HVAC 2 - Y
Call for Cool - yellow
HVAC 2 - W
Call for Heat - white
Figure 2 - Connection Descriptions

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3. Typical Wiring Diagram
R C G Y W G Y W
HVAC 1
WIRE CHANNEL
24VAC
R
C
G
Y1
W
Supply Fan
Cooling
Heating
Control Interface
Located in HVAC system
HVAC 2
HVAC 2
C
R
T-Stat Lead/Lag Controller
Back plate mounts to
standard electrical box
HVAC Unit #2
24VAC
R
C
G
Y1
W
Supply Fan
Cooling
Heating
Control Interface
Located in HVAC system
HVAC Unit #1
UP
Figure 3 –Typical Wiring Diagram

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3.0 Front Panel Display/Keypad Operation
The Quest T-Stat LLC has a 2X16 character backlit LCD display and five buttons for status review and
programming. The backlit is normally off but will turn on with a press of any key. The backlight will turn
off after a few seconds of no keys being pressed. The first press of the keypad will turn on the backlight
and tell the T-Stat to be ready for additional key presses. All keypad operation described below is after
you press and release any key to enable the backlight.
3.1 Run Mode
The display will show the current lead system along with the zone
sensor reading on the top line. The second line will show the system
status i.e. calling for cooling or heating along with the Lead fan status
of ON or Auto. Additional status information can be reviewed by pressing the up or down arrow keys.
This will cycle the display on the second line to show: Occupied status and control mode of each HVAC
unit.
3.2 Occupied Override
Press the center button until the T-Stat asks if you want to enter
occupied override mode. The default value is No. Use the up or down
arrow to change the value to Yes. Then press the center button again to
accept your choice. If you choose Yes then the T-Stat will be in occupied override mode for the
programmed delay time or unless the user presses the center button again to disable the occupied
override mode.
3.3 Lead Switch
The lead system will switch based upon an internal timer. The default setting
is every 24hours. The Lead can be switched manually by pressing the up
and down arrow simultaneously. The display will ask if you want to
switch the lead with the default answer value of No. Press the up or down arrow to change the answer
to Yes and then press the center button to do the change.
Enter Occupied?
No
Make HVAC2 Lead?
No
Lead Sys 1 80°F
Cool 1 Fan Auto

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3.4 T-Stat Settings
The T-stat LLC comes preprogrammed from Quest and cannot be changed in the field. The settings are
as follows:
Setpoint Name
Value
Normal mode - Lead unit cooling on
80
Normal mode - Lag unit cooling on
84
Normal mode - All cooling off
75
Normal mode - Lead unit heating on
45
Normal mode - Lag unit heating on
43
Normal mode - All heating off
50
Comfort mode - Lead unit cooling on
76
Comfort mode - Lag unit cooling on
80
Comfort mode - All cooling off
71
Comfort mode - Lead unit heating on
55
Comfort mode - Lag heating on
53
Comfort mode - All heating off
60
Lead Switch time
24 hours
Comfort mode time
1 hour
Lead unit fan operation
Automatic
4.0 Care and Cleaning
The T-Stat LLC should provide years of uninterrupted service. Minimal preventive maintenance is
required. However; it is important to make sure that the T-Stat is kept free of dust. A dusty T-Stat will
not allow air to circulate properly around the built-in temperature sensor effecting proper operation of
the unit.
Ensure temperature
probe in this air tunnel
is free of dirt and dust.

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5.0 Troubleshooting
LCD Screen is dark and no characters are
displayed
Remove cover and verify presence of power on the “R”
terminal, check connection of the common on the “C”
terminal. Check for presence of 24VAC between R and C.
T-Stat mode say Cool1, but compressor
does not engage
Verify connection to HVAC unit. Ensure short-cycle timer is
not inhibiting unit.
Buttons do not respond
Press buttons slowly, some functions may take pressing the
button twice.
Display is corrupted
First, cycle power to the unit. If this does not correct the
problem, reset system by removing the T-Stat body from the
mounting plate. Then return the body to the mounting plate
while depressing the up arrow, center button and down
arrow all at the same time. The display will respond with
“Cold Sense”, these buttons must be held for a minimum 5
second. This will begin a
system restart and the
display will respond with
“Cold Start”. Release the buttons at this time. This action
will reset the T-Stat and return all settings to their factory
defaults.
Contact Information:
Web Site
www.questcontrols.com
Quest Controls, Inc.
Tel: [phone], Fax: [phone]
208 9th Street Dr. West, Palmetto FL 34221
Technical & Applications Support:
[email protected]
[phone] Option 5
RMA Support:
[phone]
Cold Start