D
–EOMWC00A07-16_02EN
Operation Manual
22/77
7.10.2
Pressure condensation control
Refer to Circuit Functions.
7.11 Leaving Water Temperature (LWT) Reset
7.11.1
LWT Target
The LWT Target varies based on settings and inputs and is selected as follows:
Control Source
Set Point
Mode
Input
HP
Switch
BAS
Request
Available Modes
Set Point
Base LWT Target
Local
OFF
OFF
X
COOL
Cool Set Point 1
Local
ON
OFF
X
COOL
Cool Set Point 2
Network
X
OFF
COOL
COOL
BAS Cool Set Point
Local
OFF
OFF
X
COOL w/Glycol
Cool Set Point 1
Local
ON
OFF
X
COOL w/Glycol
Cool Set Point 2
Network
X
OFF
X
COOL w/Glycol
BAS Cool Set Point
Local
OFF
OFF
x
COOL/ICE w/Glycol
Cool Set Point 1
Local
ON
OFF
x
COOL/ICE w/Glycol
Ice Set Point
Network
x
OFF
COOL
COOL/ICE w/Glycol
BAS Cool Set Point
Network
x
OFF
ICE
COOL/ICE w/Glycol
BAS Ice Set Point
Local
x
OFF
x
ICE w/Glycol
Ice Set Point
Network
x
OFF
x
ICE w/Glycol
BAS Ice Set Point
Local
OFF
ON
X
HEAT
Heat Set Point 1
Local
ON
ON
X
HEAT
Heat Set Point 2
Network
X
x
HEAT
HEAT
BAS Heat Set Point
7.11.2
Leaving Water Temperature (LWT) Reset
The base LWT target may be reset if the unit is in Cool or Heat mode and it is configured for a reset. The type of reset to
be used is determined by the LWT Reset Type set point.
When the active reset increases, the Active LWT Target is changed at a rate of
0.05 °C
every 10 seconds. When the active
reset decreases, the Active LWT Target is changed all at once.
After resets are applied, the LWT target can never exceed a value of
15°C
.
Reset Type
– None
The Active Leaving Water variable is set equal to the current LWT set point.
Reset Type
– Return
The Active Leaving Water variable is adjusted by the return water temperature.
Start Reset Delta T
LWT set Point+Max Reset
(54)
LWT Set Point
(44)
Return Reset
0
Max Reset
(10)
Evap Delta T (
o
F)
Active
LWT
(
o
F)
The active set point is reset using the following parameters:
1. Cool LWT set point
2. Max Reset set point
3. Start Reset Delta T set point
4. Evap Delta T
