Outdoor Reset - Lochinvar KNIGHT 400 Service Manual

1
Service

Outdoor Reset

The option of controlling up to three (3) different outdoor
resets for low outdoor temperatures is available.
Outdoor (1 - 3) Low
When the outdoor air temperature drops to this point, the
water temperature will be at the Set point 1 at Low Outdoor
Temp 1, Set point 2 at Low Outdoor Temp 2 and Set point
3 at Low Outdoor Temp 3 parameters (FIG. 1-1). If the
outdoor air temperature drops further, the set point will
continue to increase above this setting. This parameter can
be changed by the installer by accessing the Outdoor (1-3)
Low parameter. The temperature range of this parameter is
-39°F (-39°C) to high outdoor temperature set point. The
default value is 25°F (-4°C).
Outdoor (1 - 3) High
When the outdoor air temperature rises to or above this
point, the water temperature will be at the Set point 1 at High
Outdoor Temp 1, Set point 2 at High Outdoor Temp 2 and
Set point 3 at High Outdoor Temp 3 parameters (FIG. 1-1).
This parameter can be changed by the installer by accessing
the Outdoor (1-3) High parameter. The temperature range
of this parameter is low outdoor temperature set point to
104°F (40°C). The default value is 70°F (21°C).
Figure 1-1 Outdoor Air Reset Curve
SET POINT AT
LOW OUTDOOR
TEMPERATURE
(SH1, SH2, SH3)
SET POINT
SET POINT AT
HIGH OUTDOOR
TEMPERATURE
22
Set Point (1 - 3) at Low Outdoor Temperature
When the outdoor air temperature drops to the Outdoor
(1 - 3) Low parameters, the calculated set point will be at
this setting (FIG. 1-1). If the outdoor air temperature drops
further, the set point will continue to increase above this
setting. However, if SH1, SH2, and SH3 are set lower, the
water temperature will be limited by these set points instead.
These parameters can be changed by the installer by accessing
the Set point 1 at Low Outdoor Temp 1, Set point 2 at Low
Outdoor Temp 2 and Set point 3 at Low Outdoor Temp 3
parameters. The temperature range of this parameter is 68°F
(20°C) to 180°F (82°C). The default value is 180°C (82°C).
Set Point (1 - 3) at High Outdoor Temperature
When the outdoor air temperature rises to or above Outdoor
(1 - 3) High parameters, the calculated set point will be at this
setting (FIG. 1-1). These parameters can be changed by the
installer by accessing the Set point 1 at High Outdoor Temp 1,
Set point 2 at High Outdoor Temp 2 and Set point 3 at High
Outdoor Temp 3 parameters. The temperature range of this
parameter is 68°F (20°C) to 190°F (88°C). The default value
is 70°F (21°C).
Outdoor Air Shutdown (SH1 - SH3)
When the outdoor temperature rises above this point, the
control will block all SH demands (DHW demands will still
be active). These parameters can be changed by the installer
by accessing the Outdoor Air Shutdown SH1, SH2, and SH3
parameters. The temperature range of this parameter is 32°F
(0°C) to 104°F (40°C). The default value is 70°F (21°C).
HIGH OUTDOOR
TEMPERATURE
LOW OUTDOOR
TEMPERATURE
Service Manual