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• The Offset setting does not change the ratio selection. For instance, with 1.00 (OD):1.00
(SYS) Reset Ratio, the System water temperature (SYS) will always increase one degree
for each degree change in the Outdoor temperature (OD). What the Offset does is add or
subtract a constant temperature value. See "Outdoor Reset Concept" on page 7.
• If required: Adjust the Water Offset in mild weather. If the ambient building
temperatures are too warm in mild weather, decrease the offset. If the ambient building
temperatures are too cold in mild weather, increase the Water Offset. The rule of thumb
for baseboard radiation is to change the offset 4°F for every 1°F you wish to change the
building temperature. In radiant heat applications, change the offset 1°F or 2°F for every
1°F you wish to change the building temperature.
outdoor cutoff teMperature
Adjustable: Off, from 20ºF / 70ºC - 100ºF / 38ºC, On
Button: MENU/Set Point/Offset/Outdoor Cutoff
• The Outdoor Cutoff screen will automatically appear after the offset has been selected.
• When the outdoor temperature falls to the adjustable Outdoor Cutoff temperature, the
Mini-MOD-CNC will control and modulate boilers to hold the calculated temperature.
• When the outdoor temperature rises to the Outdoor Cutoff plus a 2°F differential, the Mini-MOD-CNC will turn all boilers off.
The System relay will remain energized for the Run-On delay then de-energize.
• The Outdoor Cutoff can be set from 20°F to 100°F. In addition, it can be set to ON or OFF. In the ON position, the System Relay
will run regardless of the Outdoor temperature (OD) and the burner stages will be active to hold the calculated water temperature.
(Note: The lowest water temperature the Mini-MOD-CNC will circulate is 70°F. If the Outdoor Cutoff is turned ON and the
Season is set to Winter, the Mini-MOD-CNC will circulate at least 70°F water even in the hottest of weather.) In the OFF position,
the system pump will always be off and all burner stages will be off.
MInIMuM Water teMp
Adjustable from 70ºF/21ºC to 180ºF/82ºC
Button: MENU/Set Point/Offset/Outdoor Cutoff/Minimum Water Temp
• The Minimum Water Temperature must be set to the boiler manufacturer's specification.
The Mini-MOD-CNC will calculate the Set Point based on the Outdoor temperature (OD),
the Reset Ratio, and the Offset value. The Mini-MOD-CNC will control all boilers to hold
either the Set Point temperature, or the Minimum Water Temperature, whichever is higher.
• The Minimum Water Temperature must be at least 20°F lower than the Maximum
Temperature (See next setting).
MaxIMuM Water teMp
Adjustable 90ºF/21ºC - 240ºF/116ºC
Button: MENU/Set Point/Offset/..../Maximum Water Temperature
• This is the highest temperature heating water the Mini-MOD-CNC will circulate through the
heating system.
• When using a radiation system, it should be set according to the tubing or floor
manufacturer's specification.
• The Maximum Temperature must be at least 20°F higher than the Minimum Temperature
(See previous setting).
• The Maximum Temperature must be set lower than the boilers high limit for correct system
temperature control.
Mini-MOD-CNC & Mini-Extension Installation Manual
Default: 65ºF/ 18ºC
Default: 70ºF/ 21ºC
Default: 240ºF/116ºC
Offset=10°F
Min Target=120°F
Reset Ratio=1.5 : 1.0
Max Target=170°F
180
170
Max Target
160
150
140
130
120
Min Target
110
100
70
60
50
40
30
20
10
Outdoor Temperature (in °F)
Target Offset
- OUTDOOR CUTOFF -
65
o
F
[
▲
▼
BACK
SAVE
Point1: System=120°F
Point2: System=170°F
Oudoor=60°F
Oudoor=0°F
Max Target
180
170
160
150
140
130
Point1
120
Min Target
MINIMUM WATER TEMP
110
70
o
F
100
70
60
50
40
30
20
10
[
Outdoor Temperature (in °F)
Custom Reset Ratio
▲
▼
BACK
SAVE
MAXIMUM WATER TEMP
240
o
F
[
▲
▼
BACK
SAVE
23
0
-10
-20
]
Point2
0
-10
-20
]
]
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