Dip Switch Settings; Wiring - Hvac Control - Smart temp SMT-131 User Manual

DIP Switch Settings

Switch Function
Sw1 Indoor Fan Mode
Sw2 Equipment Type
Sw3 HP Mode (Sw2= ON)
HC Mode (Sw2=OFF)
Sw4 2 / 4 pipe mode
Sw5 Comp Protection Delay
Sw6 Not Used
Sw7 Ventilation Mode
Sw8 Door Station (Optional)
Note: The SMT-131 reads the switch settings on power up only. If you change any DIP switch
settings you must cycle power or press the reset button before these changes will take effect.
It is expected that only qualified people will make adjustment to these dip switch settings.
Knowledge of the HVAC system under the control of the SMT-131 is essential prior to making
adjustment to these DIP switch settings.
Caution
equipment damage. This would NOT be covered by warranty.
Wiring – HVAC Control
Terminal Designations
Terminal Function
C 24V Neutral
R 24V Active - This voltage is switched back through the relays
Hi Indoor Fan High Speed (NOT Used in Single fan speed mode - Sw 1 = OFF)
Med Indoor Fan Medium Speed (NOT Used in Single fan speed mode - Sw 1 = OFF)
Low Indoor Fan Low Speed (Used in single & three fan speed mode)
Y Compressor or Cool - (Based on Sw 2 setting)
W - O/B Reversing Valve or Heat - (Based on Sw 2 setting)
A1 – Cool 0-10V Output for Cooling (Typically used to control modulating valves)
A2 – Heat 0-10V Output for Heating (Typically used to control modulating valves)
A3 – Fan 0-10V Modulating Output for Indoor DC Fan
Com – 0V 0V terminal - Used for 0-10V, sensor or digital inputs ground reference
A Modbus Data A
B Modbus Data B
SI Remote temperature sensor input (Remote / average / Modbus data use)
DI Digital (Switched input) for forced un-occupied or initiate doorbell function
WC Window Contact - Forces SMT-131 OFF if window open > 5 min (Adjustable)
DS Door Switch – Monitors room door status for occupancy detection (see page 11)
PIR PIR ( Movement sensor) input for occupancy detection (see page 11)
The SMT-131 is powered by 24VAC and requires the 24VAC
active and neutral to be connected to the "R" (active) and "C"
(Neutral) terminals for the SMT-131 to function. The 24VAC
applied to the SMT-131 "R" terminal is switch back through
Page 5
Incorrect adjustment of these DIP switch settings could cause HVAC
On
3 Fan Speed
Heat Pump
Rev Valve Heat (B)
HE – Fan With Heat
2 pipe mode
5 Min Anti Cycle
Permitted
Fitted
Off
1 Fan Speed
Heat Cool
Rev Valve Cool (O)
HG – No Fan In Heat
4 pipe Mode
Immediate Compressor start
Not Permitted
Door Station Not Used