Daikin EWAT_B User Manual

Operating Manual
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EWAT_B
4.10.2.1 Setpoint Reset by OAT (A/C units only)
When the OAT is selected as Setpoint Reset option, the LWT active setpoint(AS) is calculated applying a correction to
the basic setpoint that depends on the ambient temperature (OAT) and on the current Unit Mode (Heating mode or Cooling
mode). Several parameters can be configured, and they are accessible from the Setpoint Reset menu, as shown below:
Provided the unit is set in Cooling mode (Heating mode), the more the ambient temperature drops below (goes beyond)
the SROAT, the more the LWT active setpoint (AS) is increased(decreased), until the OAT reaches the MROAT limit.
When the OAT overpasses the MROAT, the active setpoint does not increase(decrease) anymore, and it remains stable
to its maximum(minimum) value, i.e. AS = LWT + MR(-MR).
Graph 2 Outside Ambient Temperature vs Active Setpoint - Cooling mode(left)/ Heating mode(right)
4.10.2.2 Setpoint Reset by External 4-20Ma signal
When the 4-20mA is selected as Setpoint Reset option, the LWT active setpoint(AS) is calculated applying a correction
based on an external 4-20mA signal: 4 mA corresponds to 0°C correction, i.e. AS = LWT setpoint, whereas 20 mA
corresponds to a correction of the Max Reset (MR) quantity, i.e. AS = LWT setpoint + MR(-MR) as shown in the following
table:
Parameter
Default
Range
Description
Actual Reset
Actual Reset shows which is the correction that will applied to the base
setpoint
Max Reset (MR)
5.0°C
0.0°C10.0°C
Max Reset setpoint. It represents the maximum temperature variation
that the selection of the OAT option can cause on the LWT.
Max Reset OAT (MROAT)
15.5°C
10.0°C29.4°C
It represents the “threshold temperature” that correspond to the
maximum setpoint variation.
Start Reset OAT(SROAT)
23.8°C
10.0°C29.4°C
It represents the “threshold temperature” of the OAT to activate the
LWT setpoint reset, i.e. the LWT setpoint is overwritten only if the OAT
reaches/overpasses the SROAT.
Delta T
Is the actual evaporator delta temperature. Entering – Leaving water
temperature
OAT
Actual outside ambient temperature
Signal
Actual input current read on the terminals Setpoint Reset
SROAT
OAT
Active
Setpoint
LWT SP
MR
LWT SP + MR
MROAT
Outside Temperature trend
Outside Temperature trend
SROAT
OAT
Active
Setpoint
LWT SP - MR
MR
LWT SP
MROAT

Daikin EWAT_B Specifications

General

Brand	Daikin
Model	EWAT_B
Category	Chiller
Language	English