Air and Water cooled inverter chillers and heat pump
EWAD TZ - EWAD TZ B - EWWD VZ
Air and Water cooled inverter chillers
and heat pump
D-EOMZC00105-17EN
Operation Manual
41/84
5.1.5.2 Current Limit (Optional)
Current limit function allows to control unit power consumption taking current drawn below a specific limit.
Starting from the Current Limit Setpoint defined through the HMI or BAS communication, user can decrease
the real limit using an external 4-20mA signal as indicate in the graph below. With 20 mA real current limit is
set to Current Limit Setpoint, whereas with 4 mA signal the unit is unloaded until minimum capacity.
5.1.5.3 Setpoint Reset
The setpoint reset function overrides the chilled water temperature selected through the interface, when certain
circumstances occur. This feature helps in reducing energy consumption optimizing comfort as well. Three
different control strategies can be selected:
Setpoint Reset by Outside Air Temperature (OAT)
Setpoint Reset by an external signal (4-20mA)
Setpoint Reset by Evaporator ΔT (Return)
The following setpoints are available through this menu:
Parameter
Description
Setpoint Reset
Set the Setpoint Reset mode (None, 4-20 mA, Return, OAT)
Max Reset
Max Setpoint Reset (valid for all active modes)
Start Reset DT
Used on Setpoint Reset by Evaporator DT
Max Reset OAT
See Setpoint Reset by OAT Reset
Strt Reset OAT
See Setpoint Reset by OAT Reset
5.1.5.4 Setpoint Reset by OAT Reset (A/C units only)
The active setpoint is calculated applying a correction which is a function of ambient temperature (OAT). As
temperature drops below the Start Reset OAT (SROAT), LWT setpoint is gradually increased until OAT
reaches the Max Reset OAT value (MROAT). Beyond this value, the LWT setpoint is increased by the Max
Reset (MR) value.
Parameter
Default
Range
Max Reset (MR)
5.0°C
0.0°C
10.0°C
Max Reset OAT (MROAT)
15.5°C
10.0°C
29.4°C
Start Reset OAT(SROAT)
23.8°C
10.0°C
29.4°C
Active Setpoint (AS)
LWT Setpoint (LWT SP)
Cool/Ice LWT
SROAT
OAT
A
LWT SP
MR
LWT SP + MR
MROAT
Current
Limit [A]
Flexible
Current
Limit [mA]
4
20
Current Limit
Setpoint