User Manual

Page 9
The pipe sensor needed for 2 pipe mode is the RS-1d sensor - available as an optional part from
Smart Temp or an authorised distributor.
Klixon Mode / 2 pipe
The SMT-131 Heat and Cool mode can be changed by a remote manual mechanical switch or an
automatic Klixon switch if required. ( A klixon switch is a mechanical temperature switch typically
placed on a water pipe and use to detect water temperature, therefore selecting the correct
thermostat mode based on the temperature of water in a fan coil).
To activate Klixon mode
1 Place a Klixon switch (or mechanical switch) between the DI and Com input.
2 Turn On DIP switch 4 (Two pipe Mode = ON).
3 Turn On DIP switch 6 ( Klixon mode = ON).
4 Enter the installer menu and select option 2 (Klixon Mode) in menu item 29.
The SMT-131 will automatically change Installer Option 1 to function 2 (manual change over
mode). The user will therefore only be permitted to turn the thermostat On or Off, adjust set
temperature and fan modes (if applicable)
By default, heating mode will be selected if the switch is closed, and cooling mode will be selected
if the switch is open. Should you wish to reverse this input logic adjust Installer Option number
40.
Ancillary Functions
The SMT-131 has several additional capabilities such as communications with Building
Automation systems via its Modbus communications port. The SMT-131 will automatically control
temperature set points based on occupancy of the room when a suitable door switch and
movement sensor is fitted. The SMT-131 can even automatically shut down the air conditioning
system if balcony doors or windows are left open when the optional door / window switch are
fitted.
When you wish indication of the room status and an integrated doorbell from the hall way
outside the room, the SMT-131 can be fitted with the optional “HOT-243” hall panel.
Complete System Overview
The SMT-131 is the hub of a
compressive room comfort and
energy control system. As shown in
the picture the SMT-131 accepts
door, window and PIR contact
inputs to automatically control
temperature set points. The HOT
243 wall controller mounted in the
hallway outside of the room
provides feedback of the guests
needs to housekeeping plus
provides a convenient button to