8. Secure the thermostat to the adaptor plate with the
two machine nuts referred to in Step 3.
9. Refer to the Wiring section to connect the
terminals on the Pennswitches.
10. If a high temperature stop is desired, proceed to
the Setup and Adjustments section.
Wall Surface Mounting
To mount the thermostat directly to an interior wall
surface (no electrical box) proceed as follows:
1. At the desired thermostat location, make an
opening in the wall approximately 1/2 in. in
diameter, and pull the wires through it.
2. Plug the rest of the wall opening to prevent drafts
from affecting the operation of the thermostat
(when applicable).
3. Remove the adjusting knob, thermostat cover, and
adaptor plate. See Steps 1, 2, and 3 under
Wall Box Mounting.
4. Pull the electrical thermostat wires through the
opening in the thermostat adaptor plate.
5. Secure the adaptor plate to the mounting surface.
Note: When mounting on uneven surfaces, always
use the adaptor plate in order to prevent twisting the
unit and consequently affecting thermostat calibration
and operation.
6. Proceed as outlined in Step 6 through Step 10 in
the Wall Box Mounting section.
Wiring
Make all wiring connections using copper conductors
only in accordance with the National Electrical Code
and local regulations. Use a relay or motor starter to
handle loads that exceed the rating of the thermostat.
WARNING: Ri sk of Electric Shock.
Disconnect or isolate all power supplies before
making electrical connections. More than one
disconnection or isolation may be required to
completely de-energize equipment. Contact with
components carrying hazardous voltage can cause
electric shock and may result in severe personal
injury or death.
AVERTISSEMENT : Risque de décharge
électrique. Débrancher ou isoler toute alimentation
avant de réaliser un branchement électrique.
Plusieurs isolations et débranchements sont
peut-être nécessaires pour -couper entièrement
l'alimentation de l'équipement. Tout contact avec
des composants conducteurs de tensions
dangereuses risque d'entraîner une décharge
électrique et de provoquer des blessures graves,
voire mortelles.
For low-voltage applications, use 18 AWG wire or
larger for all connections to the thermostat. Use
14 AWG wire on runs over 500 ft. Make all splices in
junction boxes using approved solderless connectors,
or by soldering and then taping the connection.
Make all wiring connections to the screw terminals on
the Pennswitches.
• Use the terminal screws supplied with the
Pennswitches. Screws longer than 1/4 in. can
cause problems in making proper connections.
• Connect the thermostat grounding provision to the
grounding conductor of the branch circuit.
Refer to Figure 4, Figure 5, Figure 6, Figure 7, and
Figure 8 for typical wiring diagrams.
Note: Use the furnished terminal screws
(8-32 by 1/4 in. binder head). Substitution of other
screws may cause problems in making proper
connections.
T25 Two-Stage Room Thermostat Installation Instructions 3