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9 - HEAT RECLAIM CONDENSER OPTION (OPTION 50)
9.3 - Condenser location
All heat reclaim condensers are located between the air-cooled
condensers on the upper part of the chassis, support-ed by two cross
rails. The water inlet and outlet are on the same side.
9.4 - Condenser water connections
9.4.1 - Unit with one heat reclaim condenser (30XB-250 to 500)
The water flow switch must be installed at the water inlet of the
installation that arrives at the heat reclaim condenser.
Legend
1
Heat reclaim condenser
2
Entering water temperature sensor (supplied)
3
Leaving water temperature sensor (supplied)
4
Condenser water flow switch (supplied)
5
Three-way valve (not supplied)
9.4.2 - Unit with two heat reclaim condensers (30XB-600 to 1000)
The two condensers must be installed in parallel in the water system
of the installation. The water flow switch and the entering/leaving
water temperature sensors must be instal-led in the line that is
common to both heat reclaim circuits and as close as possible to
the condensers. A T-piece must be provided by the installer at the
water inlet and outlet of the condensers.
For units with two condensers the maximum cable length of the
temperature sensors and the flow switch (7.5 m) is designed to
allow connection to the common inlet or outlet in a radius of 4.5 m
after routing along the width of the unit.
Legend
Please refer to the legend in chapter 9.4.1 opposite, noting that items 2, 3 and 4 - flow
switch and sensors - are placed on the common sections.
9.4.3 - Three-way valves
It is strongly recommended to install a three-way valve in the
system (not supplied with the unit). A 0-10 V output is available
on the unit electronic board to control this valve. The valve allows
bypassing of the heat reclaim condenser entering/leaving circuit
to ensure unit operation with heat reclaim at low entering water
temperature (< 12.5 °C). It also ensures an optimal and controlled
leaving water temperature.
9.5 - Operating limits for stable operation (no mode
changeover)
9.5.1 - Cooling only mode
Please refer to the earlier chapters in this manual:
6.1 - Unit operating range
6.7 - Evaporator water flow rate
54
9.5.2 - Heat reclaim mode
Condenser water temperature
Water entering temperature at start-up
Water entering temperature during operation
Water leaving temperature during operation
Evaporator water temperature
Water entering temperature at start-up
Water entering temperature during operation
Water leaving temperature during operation
*
The water entering temperature at start-up must not be lower than 12.5 °C. For
installations with a lower temperature a three-way valve must be used.
NOTE: If the temperature at the evaporator 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 below, the unit will automatically change over
to the mode without heat recovery:
6 5
6 0
5 5
5 0
4 5
4 0
3 5
3 0
2 5
2 0
0
5
Evaporator leaving water temperature, °C
Part load limit, approx. 60%
Minimum load limit, approx. 30%
Part load operating limits (evaporator leaving water
temperature = 7 °C)
60
55
50
45
40
100
90
80
9.6 - Operating limits for changeover between modes
From cooling only to heat reclaim and vice versa.
Heat reclaim condenser water temperature
Water entering temperature
Ambient operating temperature
*
-20 °C with winter operation option (option 28)
°C
Minimum
12.5*
20
25
°C
Minimum
-
6.8
3.3
1 0
1 5
Full load
70
60
50
40
Unit load, %
°C
Minimum
Maximum
12.5
-10*
Maximum
55
55
60
Maximum
45
21
15
30
57.5
45
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