CVHH-SVX001G-EN
93
Hot Water Control
Occasionally, CenTraVac
™
chillers are selected to
provide heating as a primary mission. With hot water
temperature control, the chiller can be used as a
heating source or cooling source. This feature provides
greater application flexibility. In this case, the operator
selects a hot water temperature and the chiller capacity
is modulated to maintain the hot water setpoint.
Heating is the primary mission and cooling is a waste
product or is a secondary mission. This type of
operation requires an endless source of evaporator
load (heat), such as well or lake water. The chiller has
only one condenser.
N
No
otte
e:: Hot Water Temperature Control mode does NOT
convert the chiller to a heat pump. Heat pump
refers to the capability to change from a cooling-
driven application to a heating-driven application
by changing the refrigerant path on the chiller.
This is impractical for centrifugal chillers as it
would be much easier to switch over the water
side.
This is NOT heat recovery. Although this feature could
be used to recover heat in some form, a heat recovery
unit has a second heat exchanger on the condenser
side.
The Tracer
®
AdaptiView
™
provides the Hot Water
Temperature Control mode as standard. The leaving
condenser water temperature is controlled to a hot
water setpoint between 80°F and 140°F (26.7°C and
60.0°C). The leaving evaporator water temperature is
left to drift to satisfy the heating load of the condenser.
In this application, the evaporator is normally piped
into a lake, well, or other source of constant
temperature water for the purpose of extracting heat.
In Hot Water Temperature Control mode, all the limit
modes and diagnostics operate as in normal cooling
with one exception: the leaving condenser water
temperature sensor is an MMR diagnostic when in Hot
Water Temperature Control mode. (It is an
informational warning in the Normal Cooling mode.)
In the Hot Water Temperature Control mode, the
differential-to-start and differential-to-stop setpoints
are used with respect to the hot water setpoint instead
of with the chilled water setpoint. The control panel
provides a separate entry at the Tracer
®
AdaptiView
™
to set the hot water setpoint; Tracer
®
AdaptiView
™
is
also able to set the hot water setpoint. In the Hot Water
mode, the external chilled water setpoint is the external
hot water setpoint; that is, a single analog input is
shared at the 1K6-J2-5 to 6 (ground).
An external binary input to select external Hot Water
Control mode is on the EXOP OPTIONAL module 1K8
terminals J2-3 to J2-4 (ground). Tracer
®
AdaptiView
™
also has a binary input to select chilled water control or
hot water temperature control. There is no additional
leaving hot water temperature cutout; the HPC and
condenser limit provide for high temperature and
pressure protection.
In Hot Water Temperature Control, the softloading
pulldown rate limit operates as a softloading pullup
rate limit. The setpoint for setting the temperature rate
limit is the same setpoint for normal cooling as it is for
hot water temperature control. The hot water
temperature control feature is not designed to run with
HGBP, AFD, free cooling, or ice-building.
The factory set PID tuning values for the leaving water
temperature control are the same settings for both
normal cooling and hot water temperature control.
Control Panel Devices and Unit-
Mounted Devices
Unit Control Panel
Safety and operating controls are housed in the unit
control panel, the starter panel, and the purge control
panel. The control panel operator interface and UC800
is called Tracer
®
AdaptiView
™
and is located on an
adjustable arm connected to the base of the control
panel. For more information about operating Tracer
®
AdaptiView
™
, refer to
Tracer AdaptiView Display for
Water-Cooled CenTraVac Chillers Operations Guide
(CTV-SVU01*-EN).
The control panel houses several other controls
modules called panel-mounted Low Level Intelligent
Devices (LLIDs), power supply, terminal block, fuse,
circuit breakers, and transformer. The inter-processor
communication (IPC) bus allows the communications
between LLIDs and the UC800. Unit-mounted devices
are called frame-mounted LLIDs and can be
temperature sensors or pressure transducers. These
and other functional switches provide analog and
binary inputs to the control system.
User-Defined Language Support
Tracer
®
AdaptiView
™
is capable of displaying English
text or any of 26 other languages. Switching languages
is simply accomplished from a Language Settings
menu. The following languages are available:
•
Arabic (Gulf Regions)
•
Chinese—China
•
Chinese—Taiwan
•
Czech
•
Dutch
•
English
•
French
•
French (Canada)
•
German
•
Greek
•
Hebrew
•
Hungarian
•
Indonesian
Summary of Contents for CVHH CenTraVac
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