SPECIFICATIONS
Rated Voltage . . . . . . . .
20-30 VAC, 24 nominal
Rated A.C. . . . . . . . . . . .
0.050 Amps to 0.75 Amps continuous
Current
per output with surges to 3 Amps Max.
Rated D.C. . . . . . . . . . . .
0 Amps to 0.75 Amps continuous
Current
per output with surges to 3 Amps Max.
Control . . . . . . . . . . . . . .
Heating: 38° to 88°F in 1° Steps
Range
5° to 30°C in 1° Steps
Cooling: 60° to 108°F in 1° Steps
16° to 40°C in 1° Steps
Thermostat
Measurement Range . .
28° to 124°F or 0° to 48°C
O.D.T. Displayed
Range . . . . . . . . . . . . . . .
-50° to 119°F or -48° to 47°C
Minimum . . . . . . . . . . . .
(between heating and cooling)
Deadband
2°F or 1°C
NOTE:
This thermostat contains electronic circuitry replacing the
conventional mechanical anticipator.
MST-1
354-00019-001 Rev A
DIP SWITCH OPTIONS AND FUNCTIONS
Positioning the DIP switches in either the ON or OFF position enables you to
choose between two different options. The DIP switches are located on the
interior of your thermostat and may be accessed by following the procedure for
removing the thermostat from the subbase. The following list describes your
DIP switch options.
DIP Switch
DIP Switch OFF
DIP Switch ON
1
2
3
4
5
6
7
8
Not used (OFF position)
1 hour override
4 minute minimum ON
Keypad Unlock
Fan on with heat call
Single Stage
LED #1+No Icon
LED #2+No Icon
Not used (keep OFF)
3 hour override
2 minute minimum ON
Keypad Lock
Fan on with plenum switch
Multi-stage
LED #1+
B
Filter icon
LED #2+
A
Fault icon
1. Not Used
This switch must remain in the OFF position.
2. Temperature Override
Sets a temperature override to either 1 hour or 3
hours when the keypad is locked.
3. 2 Minute or 4 Minute On Times
This option allows you to run the equip-
ment for either a 2 or 4 minute minimum off and on time.
4. Keypad Lock
z
In the ON position locks out all buttons except the
OUTDOOR temperature button.
5. Plenum Fan Switch
In the OFF position, the fan comes on immediately
with a call for heat. In the ON position, the fan is controlled by the equipment
(plenum switch control).
6. Single or Multi-stage
This option allows you to select up to two (2) stages
of heating and cooling.
7. LED #1 + Indication
In the OFF position LED #1 will light when the
terminal is energized. In the ON position LED #1 will light and a Filter
B
icon
will be displayed on the LCD when the terminal is energized.
8. LED #2 + Indication
In the OFF position LED #2 will light when the
terminal is energized. In the ON position LED #2 will light and a Fault
A
icon
will be displayed on the LCD when the terminal is energized.
TERMINAL DESIGNATIONS
W2
.............Energizes on a call for second stage heating
Y2
..............Energizes on a call for second stage cooling
W1
.............Energizes on a call for first stage heating
Y1
..............Energizes on a call for first stage cooling
G
...............Fan operates with a call for heating or cooling or by
pressing the FAN button.
R
................Power from equipment
24V
............24 VAC hot and common to power the thermostat
24V(c)
RS2
............Use to connect up to 6 (XC-IDS) indoor and/or 1
RS1
(XC-ODT) outdoor remote sensor/s.
RS+V
When connected the thermostat will automatically use the
XC-IDS temperature sensor and not its own.
Refer to the instructions included with the sensor.
LED1..........
Free lights for status or function indication
LED2
CLK1..........
Use with dry contact relay for alternate setpoints
CLK2
X1
..........Remote communications. Refer to the instructions included
with the remote communications adapter and software.
X2
..........X1 return, connected to 24V(c)
Replacing the Thermostat on Subbase
1. Position the thermostat on the hinged
tabs at the top of the subbase.
2. Gently swing the thermostat down
and press on the bottom center until it
snaps into place.
Thermostat Cover Lock
Insert the plastic lock piece into the
bottom of the mounted base. The ends
of the lock piece fit snugly under the
lock pins extending from the bottom of
the mounted base. The tab in the mid-
dle of the lock piece extends down from
the base.
To release the locking mechanism, press
the lock piece up and into the base while
gently prying open.
Thermistor Mounting Instructions
When placing the front cover on the ther-
mostat ensure the thermistor is not bent
or misaligned.
Ensure that the thermistor does not
touch the thermostat case. The thermis-
tor should be placed horizontal to the
wall. Ensure the thermistor is not pushed
upward into the case.
The thermistor should be aligned so it is
visible between the ribs on the bottom of
the subbase.
Removing the Thermostat from the Subbase
1. Insert a flat blade screwdriver or coin 1/8" into the slot located in the bot-
tom center of the thermostat case and twist 1/4 turn. When you feel or
hear a click, grasp the case from the bottom two corners and
separate from the subbase.
2. Swing the thermostat out from the bottom.
3. Lift the thermostat up and off the subbase.
4. Place the rectangular opening in the subbase over the equipment
control wires protruding from the wall and, using the subbase as a
template, mark the location of the two mounting holes (exact vertical
mounting is necessary only for appearance).
5. Use the supplied anchors and screws for mounting on drywall or
plaster. Drill two 3/16" (5mm) diameter holes at the marked locations; use
a hammer to tap the nylon anchors in flush to the wall surface and fasten
subbase using the supplied screws. (Do not overtighten!)
6. Connect the wires from your system to the thermostat terminals. Carefully
dress the wires so that any excess is pushed back into the wall cavity or
junction box. Ensure that the wires are flush to the plastic subbase. The
access hole should be sealed or stuffed to prevent drafts from affecting
the thermostat.
INSTALLATION INSTRUCTIONS
It is recommended that installation be performed by a qualified installer.
Location
To ensure proper operation, the thermostat should be mounted on an
inside wall in a frequently occupied area of the building. In addition, its
position must be at least 18" (46cm) from any outside wall, and approxi-
mately 5' (1.5m) above the floor in a location with freely circulating air of
an average temperature. You should avoid the following locations:
- behind doors or in corners where freely circulating air is unavailable;
- where direct sunlight or radiant heat from appliances might affect con-
trol operation;
- on an outside wall;
- adjacent to, or in line with, conditioned air discharge grilles, stairwells,
or outside doors;
- where its operation may be affected by steam or water pipes or warm
air stacks in an adjacent partition space, or by an area behind the ther-
mostat which is not climate controlled;
- where its operation will be affected by the supply air of an adjacent cli-
mate control HVAC device;
- near sources of electrical interference such as arcing relay contacts.
9
11
12
16
15
14
13
10
DESCRIPTION OF ICONS
Display icons vary according to the model. Your thermostat may not
display all of the icons shown.
WIRING DIAGRAM
Note:
If the 24V(c) is not available from the equipment the shunt may be removed and
a seperate 24V transformer must be used to power the thermostat.
This thermostat may be used with 24 Volt DC. The negative side of the DC
supply must be wired to the 24V (c) terminal.
GE22-NX
