Venstar T0051FS - Manual (Page 19)

About Advanced Features & Operation
Page 18
CLOCK BACKUP - In the event of a power
thermostat’s internal clock will continue to keep
proper time for a minimum of 48 hours without
external power or batteries. The T0051FS stores
the time at which power is removed and resumes
timekeeping from that point, upon power restoration.
loss, the
2 STAGE OPERATION - The 2nd Stage of Heat or Cool is
turned on when (1) the 1st Stage has been on for a
minimum of two minutes, and (2) the temperature spread
from the setpoint is equal to or greater than: the setpoint
plus the deadband, plus 2 degrees.
Heat
Setpoint
Cool
Setpoint
Dead
Band Dead
Band
2 degrees 2 degrees
1st Stage
turn on
Fan-Low
2nd Stage
turn on
Fan-Medium
1st Stage
turn on
Fan-Low
2nd Stage
turn on
Fan-High
Heating Cooling
MINIMUM HEAT/COOL SETPOINT DIFFERENCE - The Heat
and Cool setpoints will not be allowed to come any closer
to each other than the value set in Advanced Setup step
# 16, on page 16. This minimum difference is enforced
during Auto-changeover and Program On operation.
DRY CONTACT SENSE - N.O.=Normally Open. N.O. setting
with dry contact closure enforces unoccupied settings
from normal operation. N.C.=Normally Closed. N.C.
setting with dry contact closure enforces normal operation
from unoccupied settings. This dry contact works in all
modes but OFF.