EWWQ090G ÷ EWWQ720L - R410A - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410A - Condenser less
EWHQ100G ÷ EWHQ400G - R410A - Heat pump scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWYQ-
- R410A - Air-cooled scroll heat pumps
Air and Water cooled scroll chillers & heat pump
Operation
Manual
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
Operation Manual
13
2 GENERAL DESCRIPTION
2.1 Overview
The UC is a system for controlling single or dual-circuit W/C and A/C liquid chillers / heat-pump.
The UC controls compressor start-up necessary to maintain the desired heat exchanger leaving
water temperature.
On W/C units the UC can optionally controls a three way valve or a cooling tower to perform a
condensing control. One of the following three variables can be selected as condensing target:
-
Condenser leaving water temperature (W/C only)
-
Condenser entering water temperature (W/C only)
-
Condensing saturated refrigerant temperature
Safety devices are constantly monitored by the UC to ensure their safe operation. UC also gives
access to a Test routine covering all inputs and outputs. The controller can work in accordance
with three independent modes:
Local mode: the machine is controlled by commands from the user interface.
Remote mode: the machine is controlled by remote contacts (volt-free contacts).
Network mode: the machine is controlled by commands from a BAS system. In this case, a
data communication cable is used to connect the unit to the BAS.
When the UC operates autonomously (Local or Remote mode) it retains all of its own control
capabilities but does not offer any of the command features of the Network mode (monitoring only).
2.2 Controller Operating Limits
Operation (IEC 721-3-3):
Temperature -40...+70 °C
Restriction LCD -20… +60 °C
Restriction Process-Bus -25….+70 °C
Humidity < 90 % r.h (no condensation)
Air pressure min. 700 hPa, corresponding to max. 3,000 m above sea level
Transport (IEC 721-3-2):
Temperature -40...+70 °C
Humidity < 95 % r.h (no condensation)
Air pressure min. 260 hPa, corresponding to max. 10,000 m above sea level.
2.3 Controller Architecture
The overall controller architecture is the following:
A unit controller (UC)
I/O extensions as needed depending on the configuration of the unit
Communications interface(s) as selected