Carrier AQUASNAP JUNIOR 30RA015, Данные о продукции, Страница: 45 / 48

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installed to measure cooler entering and
leaving fluid temperatures. Provision for field
installation of accessory sensor to measure
compressor return gas temperature.
2. Unit controls shall include the following functions:
a. Automatic circuit lead/lag for dual circuit
chillers.
b. Capacity control based on leaving chilled
fluid temperature and compensated by rate
of change of return-fluid temperature with
temperature set point accuracy to 0.1° F
(0.06° C).
c. Limiting the chilled fluid temperature pull-
down rate at start-up to an adjustable range
of 0.2° F to 2° F (0.11° C to 1.1° C) per
minute to prevent excessive demand spikes
at start-up.
d. Seven-day time schedule.
e. Leaving chilled fluid temperature reset from
return fluid.
f. Chilled water pump start/stop control and
primary/standby sequencing to ensure equal
pump run time.
g. Dual chiller control for parallel chiller appli-
cations without addition of hardware mod-
ules and control panels (additional
thermistor and well shall be required).
h. Unoccupied low sound operation to
limit condenser fan sound during scheduled
periods.
i. Timed maintenance scheduling to signal
maintenance activities for pumps, condenser
coil cleaning, strainer maintenance and user-
defined maintenance activities.
j. Boiler enable signal to initiate system heat-
ing mode.
k. Low ambient protection to energize cooler
and hydronic system heaters.
l. Periodic pump start to ensure pump seals
are properly maintained during off-season
periods.
3. Diagnostics:
a. The control panel shall include, as standard,
a scrolling marquee display capable of indi-
cating the safety lockout condition by dis-
playing a code for which an explanation may
be scrolled at the display.
b. Information included for display shall be:
1) Compressor lockout.
2) Loss of charge.
3) Low fluid flow.
4) Cooler freeze protection.
5) Thermistor malfunction.
6) Entering and leaving-fluid temperature.
7) Evaporator and condenser pressure.
8) Time of day:
a) Display module, in conjunction with
the microprocessor, must also be
capable of displaying the output
(results) of a service test. Service test
shall verify operation of every switch,
thermistor, fan, and compressor
before chiller is started.
b) Diagnostics shall include the ability to
review a list of the 20 most recent
alarms with clear language descrip-
tions of the alarm event. Display of
alarm codes without the ability for
clear language descriptions shall be
prohibited.
c) An alarm history buffer shall allow the
user to store no less than 20 alarm
events with clear language descrip-
tions, time and date stamp event
entry.
d) The chiller controller shall include
multiple connection ports for com-
municating with the local equipment
network, the Carrier Comfort Net-
work
® (CCN) system and the ability
to access all chiller control functions
from any point on the chiller.
e) The control system shall allow soft-
ware upgrade without the need for
new hardware modules.
4. Safeties:
a. Unit shall be equipped with thermistors and
all necessary components in conjunction
with the control system to provide the unit
with the following protections:
1) Loss of refrigerant charge.
2) Reverse rotation.
3) Low chilled fluid temperature.
4) Thermal overload.
5) High pressure.
6) Electrical overload.
7) Loss of phase.
b. Condenser fan and factory pump motors
shall have external overcurrent protection.
I. Operating Characteristics:
1. Unit shall be capable of starting and running at
outdoor ambient temperatures from 45 F (7 C)
to 120 F (50 C) for sizes 010-018 or 32 F to
120 F (0° to 52 C) for sizes 022-055.
2. Unit shall be capable of starting up with 95 F
(35 C) entering fluid temperature to the cooler.
J. Motors:
Condenser fan motors shall be totally enclosed
single or dual speed, 3-phase type with permanently
lubricated bearings and Class F insulation (except
Motormaster
® V control motors which shall be open
type and shall have Class B insulation).