Carrier Aquasnap 30RAP010, Product Data

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STANDARD CAPACITY CONTROL STEPS
Additional information — Detailed information on con-
trols and operation is available in the Controls, Operation,
and Troubleshooting literature included with each unit.
Packaged service training programs are also available.
Contact your Carrier representative for more information.
Dual chiller control — The Comfort Link controller
allows 2 chillers (piped in parallel) to operate as a single
chilled water plant with standard control functions coordi-
nated through the master chiller controller. This standard
Comfort Link feature requires a communication link
between the 2 chillers and an additional thermistor and
well in the common supply line.
Dynamic Comfort Link controls — Dynamic Com-
fort Link

controls keep the chiller on line during periods of
extreme operating conditions. If the entering fluid temper-
ature is 85 F (29 C) or higher and the saturated suction
temperature is 60 F (16 C) or higher the maximum operat-
ing pressure (MOP) feature limits the suction to keep the
chiller online. The control automatically starts the chiller in
the unloaded state to eliminate the potential of compressor
overload due to high head pressure or low suction pres-
sure. The controller will equalize run time on each circuit
through the lead/lag feature. If a circuit becomes disabled,
the control will automatically set the active circuit to lead,
keeping the chiller online at a reduced capacity.
Standard Comfort Link™ controls with scrolling
marquee display module — A four-digit alphanumeric
display shows all of the Comfort Link control codes (with
60-character expandable clear language), plus set points,
time of day, temperatures, pressures, and superheat. Addi-
tional information can be displayed all at once with the
accessory Navigator™ display.
Navigator display module — An optional 4-line,
20-character per line display is also available as a field-
installed accessory.
Low-temperature override — This feature prevents
LCWT (leaving chilled fluid temperature) from overshoot-
ing the set point and possibly causing a nuisance trip-out
by the freeze protection.
High-temperature override — This feature allows
chiller to add capacity quickly during rapid load variations.
Abnormal conditions — All control safeties in chiller
operate through compressor sensor board and the micro-
processor.
Loss of feedback signal to the MBB will cause the com-
pressor(s) to shut down. For other safeties, microprocessor
makes appropriate decision to shut down a compressor
due to a safety trip or bad sensor reading and displays
appropriate failure code on the display. Chiller holds in
safety mode until reset. It then reverts to normal control
when unit is reset.
Low-pressure safety — Safety cuts out if system pres-
sure drops below minimum.
High-pressure cutout — Switch shuts down compres-
sors if compressor discharge pressure increases to
650 psig (4482 kPa).
Compressor anti-cycling — This feature limits com-
pressor cycling.
Loss of flow protection — Proof of flow switches are
standard and installed on all 30RAP chillers.
Sensor failures — Failures are detected by the
microprocessor.
Temperature reset — The energy management module
(EMM) is required for 4 to 20 mA reset of LCWT in con-
stant fluid systems. Reset by return fluid, outdoor-air tem-
perature, or space temperature does not require this
option. Reset reduces compressor power usage at part
load when design LCWT is not necessary. Humidity con-
trol should be considered since higher coil temperatures
resulting from reset will reduce latent heat capacity. Three
reset options are offered, based on the following:
Return-fluid temperature — Increases LCWT set point as
return (or entering) fluid temperature decreases (indicating
load decrease). Option may be used in any application
where return fluid provides accurate load indication. Limi-
tation of return fluid reset is that LCWT may only be reset
to value of design return fluid temperature.
Outdoor-air temperature — Increases LCWT as outdoor
ambient temperature decreases (indicating load decrease).
This reset should be applied only where outdoor ambient
temperature is an accurate indication of load.
Space temperature — Increases LCWT as space tempera-
ture decreases (indicating load decrease). This reset should
be applied only where space temperature is an accurate
indication of load. An accessory thermistor and the energy
management module accessory is required.
For details on applying a reset option, refer to unit
Controls, operation, and Troubleshooting literature.
Obtain ordering part numbers for reset option from the
Packaged Chiller Builder program or contact your local
Carrier representative.
Accessory controls — Demand can be limited by con-
trolling the chiller capacity through the demand limit con-
trol (the energy management module is required for this
function). This FIOP (factory-installed option)/accessory
interfaces with microprocessor to control unit so that
chiller’s kW demand does not exceed its setting. It is acti-
vated from an external switch or a 4 to 20 mA signal.
UNIT
30RAP
STANDARD
CAPACITY STEPS (%)
010 0, 100
015 0, 100
01 8 0, 50, 100
020 0, 50, 100
025 0, 50, 100
030 0, 50, 100
035 0, 23, 46, 73, 100
040 0, 23, 46, 73, 100
045 0, 24, 48, 74, 100
050 0, 25, 50, 75, 100
055 0, 23, 46, 73, 100
060 0, 25, 50, 75, 100
070 0, 20, 40, 60, 80, 100
0 8 0 0, 15, 31, 46, 64, 82, 100
090 0, 17, 33, 50, 67, 83, 100
Controls (cont)