FHC-1D user manual
Phason
8
2009-06-15
Displaying and adjusting parameters
Switch position
Function
Displays the ambient temperature
Allows you to view and adjust the temperature set point
Clears alarms
Allows you to view and adjust the differential (
di
), off set-back (
oS
),
and idle speed (
id
). Each time the switch is clicked and held in this
position, the next parameter is displayed. The display flashes between
the parameter code (two letters) and it's setting (two digits). You can
adjust the parameter at this point. The cycle starts over after the last
parameter. To restart at the beginning of the cycle, click the switch to
the right.
Parameter
Code
Range
Factory setting Location
Temperature set point
N/A
32 to 99°F (0 to 38°C)
N/A
External knob
Idle speed
id
0 - 99%
N/A
External knob
Temperature differential
di
1 to 20°F (0.6 to 12°C)
6°F
Internal trimmer
Off set-back
oS
0 to 16°F (0 to 9°C)
5°F
Internal trimmer
°F or °C (ambient temp.)
°
F
/ °
C
-22 to 99°F (-30 to 38°C)
°F
Internal jumper
Changing the temperature display units
The °F/°C jumper lets you select whether the FHC-1D displays temperatures in degrees Fahrenheit
or Celsius. To change the setting, position the jumper as shown in section D on page 4.
About the hysteresis
The FHC-1D has a 1°F (0.5°C) hysteresis. This means the fan will turn off 1°F below the point it
turned on.
For example, if TEMP SET is 75°F, the fan will turn on at 75°F, off at 74°F. This prevents the fan
from flickering on and off at the TEMP SET.
