AIR-COOLED LIQUID CHILLERS 30XA 252-1702
■■ The Energy Management Module (EMM) offers extended
remote control possibilities:
-- Room temperature: Permits set-point reset based
on the building indoor air temperature (if Carrier
thermostat are installed)
-- Set-point reset: Ensures reset of the cooling set-point
based on a 4-20 mA or 0-10 V signal
-- Demand limit: Permits limitation of the maximum
chiller capacity based on 0-10 V signal
-- Demand limit 1 and 2: Closing of these contacts limits
the maximum chiller capacity to two predefined values
-- User safety: This co ntact can be used for any
customer safety loop; opening the contact generates
a specific alarm
-- Ice storage end: When ice storage has finished,
this input permits return to the second set-point
(unoccupied mode)
-- Time schedule override: Closing of this contact
cancels the time schedule effects
-- Out of service: This signal indicates that the chiller is
completelt out of service
-- Chiller capacity: This analogue output (0-10 V) gives
an immediate indication of the chiller capacity
-- Alert indication: This volt-free contact indicates the
necessity to carry out a maintenance operation or the
presence of a minor fault
-- Compressors running status: Set of outputs (as
many as the compressors number) indicating which
compressors are running.
COOLING
Remote Management (EMM option)
Total heat reclaim (option 50)
Note: Heat reclaim is only possible, if the unit produces cold
water at the same time.
*
Condenser water temperature (°C)
Min
Max
Entering temperature at start-up
Entering temperature during operation
Leaving temperature during operation
Evaporator water temperature (°C)
Entering temperature at start-up
Entering temperature during operation
12.5*
20
25
55
55
60
6.8
45
21
The entering water temperature at start-up must not fall below 12.5 °C.
For installations with a lower temperature a three-way valve must be used.
Note: If the evaporator leaving water temperature is below 4 °C, a glycol-water solution or
the frost protection option must be used.
In part-load operation, the limitation of the condenser leaving
water temperature is due to the operating range of the screw
compressor. If the condenser leaving water temperature is
above the limit value given in the curves on the right, the
unit will automatically change over to the mode without heat
recovery:
C
A
R
R
I
E
R
2
0
1
6
/
2
0
1
7
50
HEATING HEATING
45
40
35
30
25
20
0
5
10
Evaporator leaving water temperature, °C
15
Full load
Part load limit, approx. 60%
Minimum load limit, approx. 30%
AIR TREATMENT
If hot water production is required, the compressor discharge
gases are directed towards the heat reclaim condenser. The
refrigerant releases its heat to the hot water that leaves
the condenser at a temperature of up to 60 °C. In this way
100% of the heat rejected by the liquid chiller can be used
to produce hot water. When the demand for heat is satisfied,
the hot gas is again directed towards the air condenser where
the heat is rejected to the outside air by the fans. Hot water
temperature control is ensured by the chiller Touch Pilot
control that independently controls the reclaim operation of
each refrigerant circuit.
55
Part load operating limits (evaporator leaving
water temperature = 7 °C)
60
55
50
45
40
100
90
80
70
60
Unit load, %
50
40
30
181
CONTROLS
Operating principle
60
Condenser leaving water temperature, °C
With the total heat reclaim option it is possible to reduce
the energy consumption bill considerably compared to
conventional heating equipment such as fossil fuel boilers or
electric water tanks.
65
Maximum condenser leaving water
temperature, °C
Suitable for heating, domestic hot water preparation,
agriculture and food industry, industrial processes and other
hot-water requirements.