Venstar T1800 Owner's Manual page 77

Explanation of Jumper Settings
W3 JUMPER SETTING
If the jumper for MISC1, MISC2, or MISC3 is set to W3, the corresponding MISC screw terminal
on the backplate will control a third stage of heat.
W3 MULTI-STAGE OPERATION EXPLAINED - PAGE 13.4
The 3rd Stage of Heat is turned on when:
(A) The 1st and 2nd stages have been on for the time required (steps #23
and #24 page 13.6). It is adjustable from 0-60 minutes and the default
And
is two minutes.
(B) The temperature from the setpoint is equal to or greater than: the set-
point plus the 1st stage deadband (step #20, 13.5), plus the 2nd stage
deadband (step #21, 13.5) plus the 3rd stage deadband (step #22,
13.5). This 3rd stage deadband is adjustable from 0-10 degrees and
the default is two degrees.
Heating
Deadband Deadband
db 3 db 2
(adj. 0-10 ) (adj. 0-10 )
3rd Stage 2nd Stage 1st Stage
turn on turn on turn on
DECREASE
HUM JUMPER SETTING
If the jumper for MISC1, MISC2, or MISC3 is set to HUM,
terminal on the backplate will control a humidification system.
18
HUMIDIFICATION OPERATION - SECTION 9
If your HVAC unit is equipped with a humidification system and the
Humidity Module (sold separately) has been installed, the thermostat will
provide power to the MISC1, MISC2, or MISC3 terminal of the thermostat
when the humidity in the home falls below the humidity setpoint you have
chosen. The value for this setpoint ranges from 0% to 60%. If no
humidity is desired or if a humidification system has not been installed, set
the value to 0%.
Cooling
Deadband Deadband Deadband
db 1 db 1 db 2
(adj. 1-6 ) (adj. 1-6 ) (adj. 0-10 )
Heat Cool 1st Stage
Setpoint Setpoint turn on
TEMPERATURE INCREASE
the corresponding MISC screw
Page 18.3
2nd Stage
turn on