Lennox International Inc. SLP9801 Thermostat User Manual


 
icomfort Wi-Fit 7−Day Programmable Communicating Thermostat
Page 31
Smooth Setback Recovery (SSR)
SSR is an algorithm designed to smoothly" reach a occupied program
schedule setpoint. The algorithm looks 2 hours ahead for the occupied pro-
gram schedule period’s setpoint. If the occupied setpoint requires the sys-
tem to turn on (present temperature below the heat setpoint or above the
cool setpoint), then SSR will calculate a new setpoint. Once initiated, SSR
monitors the change in room temperature and calculates a new setpoint ev-
ery 30 seconds. Then SSR provides this new setpoint for the heating and
cooling algorithms; the new setpoint will be displayed on the User Interface.
Rules for SSR:
1. SSR is enabled when Smooth Setback Recovery" is set to enabled
and the program schedule is turned on.
2. When SSR is enabled, then it will check for a new setpoint every 30
seconds.
3. The SSR Target Program Schedule setpoint is always 2 hours ahead.
4. When SSR starts, then the Current SSR setpoint will equal the current
program schedule setpoint.
5. When a new program schedule period starts, then the New SSR set-
point will equal the new program schedule period’s setpoint, unless
there are two or more program periods within the 2 hour window. In this
case, SSR will track the highest heat setpoint or the lowest cool set-
point found in the 2 hour window.
6. SSR will NOT run during a program schedule HOLD.
7. SSR does NOT look at the current temperature.
8. If the target program heat setpoint is lower than the Current SSR heat
setpoint, then the New SSR Heat Setpoint will equal the Current SSR
Setpoint.
9. If the target program cool setpoint is higher than the Current SSR cool
setpoint, then the New SSR Cool Setpoint will equal the Current SSR
Setpoint.
10. The New SSR Setpoint will be displayed on the User Interface.
11. SSR does NOT control the equipment.
12. SSR does NOT turn off Stage Delay Timers.
13. SSR does NOT round the newly rounded setpoint, but the setpoint
shown on the user interface is rounded.
14. SSR will NOT change the Temperature Dead band.
15. SSR will not adjust a setpoint to violate the Temperature Dead band.
16. SSR will not overshoot the Target Setpoint.