34
12. Outdoor Reset Control
Section XII: Outdoor Reset Control
An outdoor reset function is included in the CHALLENGER control.
The use of the outdoor reset function is required to optimize boiler
efficiency, see notice below. If the outdoor sensor is not installed,
ODS will be displayed. This display will not prevent the appliance from
operating. The ODS display will automatically reset once the outdoor
sensor is installed.
12.1 Mounting the Outdoor Sensor
Remove the front cover and mounting screws / anchors from
1.
the sensor enclosure.
When mounting the enclosure, the exterior wall selected should
2.
represent the coldest outdoor temperature. Typically a northern
or northeastern wall will suit most buildings. A southern facing
wall may suit buildings that have large glass walls or windows on
the southern face.
Ensure the sensor enclosure is shielded from direct sunlight or
3.
the effects of heat or cold from other sources (exhaust fans,
appliance vents...) to prevent false temperature sensing.
Mount the sensor enclosure at an elevation on the exterior wall
4.
to prevent accidental damage or tampering.
Avoid mounting the enclosure in areas subjected to excessive
5.
moisture.
Once an area on the exterior wall has been determined use the
6.
enclosure as a template to mark the location of the mounting
screws.
Using a 3/16” [5 mm] drill bit, drill 2 pilot holes on the marked
7.
locations.
Tap the enclosed plastic anchors into the pilot holes. Use care
8.
not to damage the anchors.
Mount the sensor enclosure using the screws provided.
9.
12.2 Wiring the Outdoor Sensor
Route two 18 gauge wires through the seal gasket. Connect the
1.
wires to sensor terminals 1 and 2.
Route the sensor wire back to the CHALLENGER, ensuring the
2.
wires are not run parallel to telephone or power cables.
Connect the sensor wires to the outdoor sensor terminals 9 and
3.
10 of the low voltage X4 connector located on the control (see
appliance wiring diagram, Fig. 12 on page 19).
12.3 Adjusting Outdoor Reset Curve
The appliance CH set point along with Parameters 5, 6, and 7 define
the settings of the outdoor reset curve. See Graph 1 and Table 7, on
page 35, for an example of modifying the outdoor reset curve.
12.3.1
CH Maximum Boiler Temperature
If an outdoor temperature sensor is not connected to the appliance,
the appliance setpoint for a heating call will be set to the CH
Maximum Boiler Temperature. If an outdoor temperature sensor is
connected, the CH Maximum Boiler Temperature becomes the
appliance setpoint on the CH Reset Curve Coldest Day.
In accordance with Section 325 (f) (3) of the Energy
Policy and Conservation Act, this boiler is equipped
with a feature that saves energy by reducing the boiler
water temperature as the heating load decreases. This
feature is equipped with an override which is provided
primarily to permit the use of an external energy man-
agement system that serves the same function.
THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST
ONE OF THE FOLLOWING CONDITIONS IS TRUE:
An external energy management system is installed
1.
that reduces the boiler water temperature as the
heating load decreases.
This boiler is not used for any space heating
2.
This boiler is part of a modular or multiple boiler
3.
system having a total input of 300,000 BTU/hr or
greater.
This boiler is equipped with a tankless coil.
4.
NOTICE
Sensor Enclosure
Plastic Anchors (2)
Seal Gasket
Front Cover
Mounting
Screws
(2)
Fig. 18: Outdoor Sensor Enclosure and Components
If the sensor wires are located in an area with sources
of potential electromagnetic interference (close to 120
V wiring) the sensor wires should be shielded or the
wires should be routed in a grounded metal conduit. If
using shielded cable, the shielding should be connected
to the common ground of the appliance.
NOTICE
Factory Setting
Minimum
Setting
Maximum
Setting
186°F
[86°C]
86°F
[30°C]
194°F
[90°C]
Содержание CC105s
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