Lochinvar SMART SYSTEM 502 - 2072 - Manual (Page 18)

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Service
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F3: Maximum SH set point
When the outdoor temperature drops to its minimum
setting (F1) the water temperature set point will be at this
value, 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 32°F (0°C) to 248°F (120°C). The default value is 180°F
(82°C).
F4: Minimum SH set point
When the outdoor temperature rises to or above its
maximum setting (F2) the water temperature will be at
this value (FIG. 1-1). This parameter can be changed by
the installer by accessing parameter F4. The temperature
range of this parameter is 32°F (0°C) to 248°F (120°C).
The default value is 70°F (21°C).
F5: 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 32°F (0°C) to 122°F
(50°C). The default value is 80°F (27°C).
Figure 1-1_Outdoor Air Reset Curve
F: Outdoor air reset (boiler only)
Outdoor air reset operation
When the outdoor air sensor is installed, the control will
calculate the water temperature set point based on the outdoor
air temperature. As the outdoor air temperature drops, the
water temperature set point increases. This feature allows
the unit to be more efficient in periods of mild weather, see
FIG. 1-1 on page 17.
F1: Minimum air temperature
When the outdoor air temperature drops to this point, the
water temperature will be at its maximum setting (FIG. 1-1). The
set point will continue to increase as the outdoor temperature
drops below this setting. The water temperature will be limited
by the user set point. This parameter can be changed by the
installer by accessing parameter F1. The temperature range
of this parameter is -22°F (-30°C) to 86°F (30°C). The default
value is 25°F (-4°C).
F2: 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 -22°F (-30°C) to 86°F (30°C). The default value
is 70°F (21°C).
Copper-fin II/IIE Boiler, Water Heater and Pool Service Manual