NTI Ti100-200 Installation And Operation Instructions Manual page 45

Ti Series
Outdoor Sensor (10K)
To fully take advantage of the energy saving features of the Trinity boiler, it is necessary to install the outdoor sensor provided.
Install the sensor preferably on the north, or coldest side of the building, not within 10 feet of the discharge of the gas vent outlet,
or other sources of heat. The outdoor sensor connects to the top of the boiler on terminals O and D.
Calculating Outdoor Reset Curve (RES)
Formula:
Operating Temperature (HI
Example:

There is a call for heat and no call for domestic hot water (T-C closed & A-C open), the control
uses the programmed HI and RES settings and the current outdoor temperature.

The HI is programmed to be 160°F.

The RES is programmed to be 85°F.

The outdoor temperature is 40°F.
Operating Temperature = {(85 – 40) x (160 – 85) / 85} + 85 = 125°F
The following chart illustrates the effect of changing outdoor temperature on the boiler operating temperature for
the above example.
170
150
130
110
90
70
-10
Table 12-4 Low Voltage Field Connections
Boiler Set Point – HI
80 – 110
110 – 140
140 – 170
170 – 200
) = {(RES – Outdoor Temp) x (HI – RES) / RES} + RES
CALC.
Reset Curve for Res=85 & Setpoint=160
0 10 20 30
Outdoor Temperature (deg.F)
Outdoor Reset – RES
70 – 80
80 – 90
90 – 100
100 – 110
Installation and Operation Instructions │Trinity
40 50 60 70 80 90 100
45