Lochinvar KNIGHT 399 - Manual (Page 19)

1
Service
Service Manual
19
1
Service
(continued)
WATER
TEMPERATURE
SET POINT
MAXIMUM
RESET
Default = 180°F
USER
SET POINT
Default = 125°F
MINIMUM
RESET
Default = 70°F
Default = 25°F Default = 70°F
OUTDOOR AIR
AT MAXIMUM RESET
OUTDOOR AIR
AT MINIMUM RESET
OUTDOOR
TEMPERATURE
Figure 1-1 Outdoor Air Reset Curve
Maximum air temperature
When the outdoor air temperature rises to or above this
point, the water temperature will be at its minimum setting
(FIG. 1-1). This parameter can be changed by the installer by
accessing parameter F2. The temperature range of this
parameter is -30°F (-34°C) to 90°F (32°C). The default value
is 70°F (21°C).
Maximum SH set point
When the outdoor temperature drops below its minimum
setting (F1) the water temperature will be at this point, if the
SH set point is set higher (FIG. 1-1). This parameter can be
changed by the installer by accessing parameter F3. The
temperature range of this parameter is 0°F (-18°C) to 190°F
(88°C). The default value is 180°F (82°C).
Minimum SH set point
When the outdoor temperature rises to or above its
maximum setting (F2) the water temperature will be at this
point (FIG. 1-1). This parameter can be changed by the
installer by accessing parameter F4. The temperature range of
this parameter is 0°F (-18°C) to 190°F (88°C). The default
value is 70°F (21°C).
Outdoor air shutdown
When the outdoor temperature rises above this point, the
control will block all SH demands (DHW demands will still
be active). This parameter can be changed by the user or the
installer by accessing parameter F5. The temperature range of
this parameter is 0°F (-18°C) to 120°F (49°C). The default
value is 70°F (21°C).
Outdoor air shutdown differential
The outdoor air shutdown differential parameter is the
number of degrees below parameter F5 the outdoor air
temperature must go before the boiler will respond to a SH
demand. This parameter can be changed by the user or the
installer by accessing parameter F6. The temperature range of
this parameter is 0°F (0°) to 90°F (50°C). The default value is
10°F (5°C).
Shift reset curve
The shift reset curve parameter shifts the actual set point
above the calculated set point the number of degrees in this
parameter. This parameter can be changed by the installer by
accessing parameter F7. The temperature range of this
parameter is -27°F (-15°C) to 27°F (15°C). The default value
is 0°F (0°C). This feature will be active if this parameter is set
to anything other than 0°F (0°C).