heat-timer DiGi-SPAN Elite Series Assembly, Installation And Operation Instructions page 7

numbered Reset Ratio curve should be selected.
• If required: Adjust the RESET RATiO in cold weather. If the ambient building temperatures are too cold in cold weather, move
the ratio to a higher selection. That is, if 1.00 (OD):1.00 (SYS) was initially selected, change the selection to 1.00 (OD):1.25 (SYS).
If the building temperatures are too warm in cold weather, move the ratio to a lower selection. That is, if 1.00 (OD):1.00 (SYS) was
initially selected, change the selection to 1.25 (OD):1.00 (SYS).
• The Custom option gives the user the capability of creating a specialized Reset Ratio curve. Setting two points on the Reset Ratio
chart generates the customized curve. Each point requires a System Water Temperature and an Outdoor Temperature. The line
connecting the two points will be the customized reset ratio.
• Reset Ratios are adjustable based on the building and application. See suggested ratios on page 2.
Custom Outdoor Reset Curve
(Available when Startup Control Mode = Outdoor Reset)
Options: Sys Temp 1, 2 (-10ºF/21ºC) to (210ºF/99ºC)
Options: Outdoor Temp 1, 2 (-10ºF/-23ºC) to (100ºF/38ºC) Default: 1(70ºF/21ºC), 2(0ºF/-18ºC)
/<Out. Reset>/Reset Ratio/Custom
SET
• For situations where the provided reset ratios do not provide the perfect building heat-loss
equilibrium, the customized option can be used.
• The Custom Reset Ratio is only available when Custom is selected from the Reset Ratio menu
option. It provides the user with the capability of assigning two points on the reset ratio diagram
and use the line that connects those two points as the customized reset ratio curve. Each of the two
points will need a specific System and Outdoor Temperature to identify it on the diagram.
• To Set the first point, specify Sys Temp 1, and OD Temp 1. Then, specify Sys Temp 2, and OD
Temp 2, to set the second point on the curve. The two points can be any where on the line, not
necessarily at the ends.
• The chart shows an example of a customized curve 6(OD):5(SYS) that do not exist in the standard
curve options. If the outdoor temperature reaches 30ºF, the system target will be 145ºF.
• Remember that the Min Target and Max Target apply to all reset ratios including the customized
reset ratio ones.
Offset
(Available when Startup Control Mode = Outdoor Reset)
Options: From -40ºF/-22ºC to +40ºF/+22ºC
/<Out. Reset>/Offset
SET
• The Offset setting lets you adjust the starting points of the Reset Ratio curves. This means that, regardless of the Outdoor
temperature (OD), or the Reset Ratio that has been selected, when the Offset setting is changed, that change is directly added to or
subtracted from the calculated temperature/Target. For example, if the Set Point temperature was 130°F and the Offset was changed
from 0° to +10°, then the Set Point temperature would increase to 140°F
• If required: Adjust the Water Offset in mild weather. If the ambient building temperatures are too warm in the mild weather,
decrease the Offset. If the ambient building temperatures are too cold in the mild weather, increase the 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 temperatures. 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
Options: Off, 20ºF/0ºC to 100ºF/25ºC, On Default: 65ºF
/Set Point/Cutoff in Set Point
SET
/Set Point/<Out. Reset>/Cutoff in Reset
SET
• In Set Point, if the outdoor sensor is installed, the Outdoor Cutoff setting screen will automatically
appear after the temperature Set Point has been selected.
• The Outdoor and its Cutoff temperatures can be viewed from the default screen by clicking the Up or Down buttons.
• When the outdoor temperature falls to the adjustable Outdoor Cutoff temperature, the HWE-MOV will control the System Pump
and Motorized valve relays to provide heat.
• When the outdoor temperature rises to the Outdoor Cutoff plus a 2°F differential, the HWE-MOV will energize the Motorized Valve
Close relay for 6 minutes to guarantee valve closure. The System relay will remain energized for the Run-On delay.
• The Outdoor Cutoff can be set from 20°F to 100°F. In addition, the Setting can be set to ON or OFF. If ON is selected, the System
Relay will energize regardless of the Outdoor temperature and the HWE-MOV will the control the motorized valve to hold the
target temperature. If OFF is selected, the System and Open relays will always be off.
7
Default: 1(100ºF/38ºC), 2(171ºF/77ºC)
Default: 0ºF/0ºC
HWE-MOV Digi-Elite Operation Manual
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 0 -10
Outdoor Temperature (in °F)
Target Offset
Set SYS Temp 1:
100 F
At OD Temp 1:
70 F
Point1: System=120°F Point2: System=170°F
Oudoor=60°F Oudoor=0°F
Max Target
180
170 Point2
160
150
140
130
Point1 Min Target
120
110
100
70 60 50 40 30 20 10 0 -10
Outdoor Temperature (in °F)
Custom Reset Ratio
Offset:
+0 F
Cutoff:
60 F
-20
-20