Natural Ventilation Control
Phason
12
2013-08-26
How the heater settings work
When the temperature is below the
Heat set point
, the NVC-2 switches the heater on. When the
temperature is above the
Heat set point
plus the
Hysteresis
, the NVC-2 switches the heater off.
For more information about hysteresis and how it affects operation, read
How hysteresis works
below.
To program the Heat set point
Default: 75.0°F, range: -13 to 124°F (-25 to 51.1°C)
1.
Press
Up
or
Down
until the display shows
Heat
.
2.
Press
Select
.
The current setting (in degrees) displays and the
Heat set point
LED flashes.
3.
Press
Up
or
Down
to adjust the setting and then press
Select
.
The change is saved and the display shows
Heat
.
4.
Press
Down
to move to the
High alarm
, or
Back
to cancel and return to the main display.
How hysteresis works
Hysteresis is the number of degrees above the set point
that a heating stage or relay switches off.
For example, a household thermostat might switch on a
furnace at 67°F when the house is cooling down, but
switch it off at 70°F when the house is warming up. The
difference between these two values is the hysteresis.
To program the Hysteresis
Default: 2.0°F, range: 0.5 to 5°F (0.3 to 2.8°C)
1.
Press
Up
or
Down
until the display shows
Hyst
.
2.
Press
Select
.
The current setting (in degrees) displays and the
Hysteresis
LED flashes.
3.
Press
Up
or
Down
to adjust the setting and then press
Select
.
The change is saved and the display shows
Hyst
.
4.
Press
Down
to move to
Units
, or
Back
to cancel and return to the main display.
Set point: 67°F
Hysteresis: 3°F
Set point+
hysteresis: 70°F
Heater OFF
Example for heaters
