R
COOLING
Remote management ( standard )
A simple two-wire communication bus between the RS485 port of the AquaSnap and the Carrier Comfort Network offers multiple remote control , monitoring and diagnostic possibilities . Carrier offers a vast choice of control products , specially designed to control , manage and supervise the operation of an air conditioning system . Please consult your Carrier representative for more information on these products .
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Start / stop : Opening of this contact will shut down the unit
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Dual set point : Closing of this contact activates a second set point ( example : unoccupied mode )
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Demand limit : Closing of this contact limits the maximum chiller capacity to a predefined value
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User safety : This contact is connected in series with the water flow switch and can be used for any customer safety loop
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Heat reclaim ( option ): Closing of this contact allows heat reclaim mode operation
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Water pump 1 and 2 control *: These outputs control the contactors of one or two evaporator water pumps
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Water pump on reversal *: These contacts are used to detect a water pump operation fault and automatically change over to the other pump
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Operation indication : This volt-free contact indicates that the chiller is operating ( cooling load ) or that it is ready to operate ( no cooling load )
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Alert indication : This volt-free contact indicates the presence of a minor fault
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Alarm indication : This volt-free contact indicates the presence of a major fault that has led to the shutdown of one or two refrigerant circuits
* Contacts already supplied with the hydronic module option
All aluminium micro-channel heat exchanger ( MCHE )
Already utilised in the automobile and aeronautical industries for many years , the MCHE heat exchanger is entirely made of aluminium . This one-piece concept significantly increases its corrosion resistance by eliminating the galvanic currents that are created when two different metals ( copper and aluminium ) come into contact in traditional heat exchangers . Unlike traditional heat exchangers the MCHE heat exchanger can be used in moderate marine and urban environments .
From an energy efficiency point-of-view the MCHE heat exchanger is approximately 10 % more efficient than a traditional coil and allows a 40 % reduction in the amount of refrigerant used in the chiller . The low thickness of the MCHE reduces air pressure losses by 50 % and makes it less susceptible to fouling ( e . g . by sand ) than a traditional coil . Cleaning of the MCHE heat exchanger is very fast using a high-pressure washer .
Controls
Pro-Dialog Plus control
Pro-Dialog Plus combines intelligence with operating simplicity . The control constantly monitors all machine parameters and precisely manages the operation of compressors , expansion devices , fans and of the evaporator water pump for optimum energy efficiency .
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Energy management --
Internal time schedule clock : permits chiller on / off control and operation at a second set point
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Set point reset based on the outside air temperature or the return water temperature
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Master / slave control of two chillers operating in parallel with operating time equalisation and automatic change-over in case of a unit fault .
-- Start / stop control based on the air temperature
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Ease-of-use --
User interface with synoptic diagram for intuitive display of the principal operating parameters : number of compressors operating , suction / discharge pressure , compressor operating hours , set point , air temperature , entering / leaving water temperature
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Ten menus for direct access to all machine commands , including fault history , allowing fast and complete chiller diagnostics
Pro-Dialog Plus operator interface
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