4
UNT-PRC002-GB
Technical Data
FWD
08
12
20
30
45
Power supply
(V/Ph/Hz)
230/1/50
Capacities
Cooling capacity on water (1)
(kW)
5,2
8,3
15
18,8
30,1
Heating capacity on water (2)
(kW)
6,3
11,9
18,9
20,9
38,2
Fan motor
(type)
2 x direct drive centrifugal
Fan power input (3)
(kW)
0,23
0,46
0,65
1,04
1,51
Current amps (3)
(A)
1,1
2,2
3,1
4,7
5,5
Start-up amps
(A)
3,2
5,5
9,3
14,1
16,5
Air flow
minimum
(m
3
/h)
490
980
1400
1800
2700
nominal
(m
3
/h)
820
1650
2300
3000
4500
maximum
(m
3
/h)
980
1970
2600
3600
5400
Main coil
Water entering/leaving connections
(type)
ISO R7 rotating female
(Dia)
3/4"
3/4"
1 1/2"
1 1/2"
1 1/2"
Electric heater (accessory for blower only)
Electric power supply
(V/Ph/Hz)
230/1/50
230/1/50 or 400/3/50
400/3/50
400/3/50
400/3/50
Heating capacity
(kW)
2/4
8
10
12
12
Hot water coil (accessory for blower only)
Heating capacity (4)
(kW)
6,3
12
17,4
22,4
34,5
G2 filter (filter box accessory)
Quantity
2
2
2
2
2
Dimensions ( LxWxth)
(mm)
386x221x8
486x271x8
586x321x8
586*421*8
586*621*8
G4 filter (filter box accessory)
Quantity
-
2
2
2
2
Dimensions ( LxWxth)
(mm)
-
486x264x48
586x314x48
586*414*48
586*614*48
Condensate pump (accessory)
(type)
Centrifugal
Water flow - lift height
(l/h - mm)
24 - 500
Not available for FWD30 and FWD45
Sound level (L/M/H speed)
Sound pressure level (5)
(dB(A))
36/40/43
38/41/44
46/50/53
47/52/57
47/52/58
Sound power level (5)
(dB(A))
46/50/53
48/51/54
56/60/63
57/62/67
57/62/68
Unit dimensions
Width x Depth
(mm)
890 x 600
1090 x 710
1290 x 820
1290 x 970
1290 x 1090
Height
(mm)
250
300
350
450
650
Shipped unit dimensions
Width x Depth
(mm)
933 x 644
1133 x 754
1333 x 864
1333 x 1008
1333*1133
Height
(mm)
260
310
360
460
660
Weight
(kg)
32
46
61
76
118
Colour
galvanised steel
Recommended fuse size
Unit alone (aM/gI)
(A)
8/16
8/16
8/16
8/25
8/25
Unit with electric heater (gI)
(A)
16 (2kW),25 (4kW)
40 (230V),3*16 (400V)
3*20
3*25
3*25
(1) Conditions: Water entering/leaving temperature: 7/12 °C, Air inlet temperature 27/19°C DB/WB - Nominal air flow
(2) Conditions: Water entering/leaving temperature: 50/45 °C, Air inlet temperature 20°C DB - Nominal air flow
(3) At high speed with nominal air flow.
(4) Water entering/leaving temperature 90/70 °C, air inlet temperature 20 °C DB, Nominal air flow.
(5) A rectangular glass wool duct 1m50 long is placed on the blower.The measurement is taken in the room containing the blower unit.
Heat exchanger operating limits:
FWD:
*water temperature: max 100° C
*absolute service pressure: min 1 bar/max 11 bars
Accessories - Hot water coil:
*water temperature: min. +2° C/max. 100° C
*absolute service pressure: min 1 bar/max 11 bars
CG-SVX051A-GB
34
Minimum/recommended water
content
The water volume is an important parameter because it
permit several things:
1. It avoids short cycle operation of the compressors.
Parameters which influence the minimum
compressor running time
−
Water loop volume
−
Load fluctuation
−
Number of capacity steps
−
Compressors rotation
−
Dead band (adjustable on unit controller)
−
Minimum running time of a compressor
2. On both chilled and hot water loops, it permits to
smooth water temperature fluctuations leaving the
CMAF unit whilst a circuit transitions from a mode to
another.
3. On hot water loop it permits to keep a leaving
temperature hot enough when defrosting cycles
occur :
−
Assures the unit to defrost both circuits in a row
−
Assures continuous operation and to run
Exchangers the most effective way.
For chilled water loop, the minimum water content shall
be in accordance with point 1.
For hot water loop, the minimum water content shall be
the maximum of recommendations #1 and #2.
1. Avoid short-cycles
For comfort application, we can allow water temperature
fluctuation at part load. The parameter to take into
account is the minimum operating time of the
compressor. In order to avoid lubrication problem on a
scroll compressor it must run at least 2 minutes
(120 seconds) before it stops.
The minimum volume can be determined by using the
following formula:
Volume =
With :
•
Maximum unit capacity (kW) at full load
•
time (seconds),120s minimum operating time
•
step
high
(%),
•
specific heat (kJ/kg) e.g.4.18 for water
•
dead band (K) (default value see Table 9)
Table 8 – Brine specific heat (kJ/kg) at 30% concentration
Temperature
(°C)
Propylene
Glycol
Ethylene
Glycol
-10
4.80
4.30
0
4.44
4.22
10
4.18
4.07
20
4.00
3.87
30
3.86
3.65
40
3.72
3.41
50
3.55
3.18
60
3.31
2.97
70
2.96
2.80
Table 9 - Default Dead band and highest compressor step
Unit Size
080
090
100
110
130
Highest Step
25%
27%
25%
29%
25%
Default Dead
Band
1.8
Unit Size
140
150
165
180
190
Highest Step
18%
17%
20%
18%
17%
Default Dead
Band
1.3
Note:
To estimate the capacity, it is recommended
to make a selection at full load according ambient
temperature which the needs are the lowest and the unit
cooling/heating capacities the highest, e.g.
•
The lowest ambient air temperature for cooling
mode
•
The highest ambient air temperature for heat pump
mode.
It is also essential to take into account the brine specific
heat, in case of the use of glycol refer to Table 6.
Process applications will need more water volume to
minimize the water temperature fluctuation at part load.
2. Coil defrosting
When the unit is running in heat pump mode with
ambient air temperature below +7°C coils may be subject
to ice formation. The unit controller can initiate a defrost
cycle to melt the ice in order to recover a reasonable
capacity.
In case ambient air will not drop below +7°C
recommendations below do not apply.
The leaving temperature may be colder during few
minutes defrosting and shall be mixed into a buffer tank.
Chilled/hot water Piping
(largest compressorTonnage)
(unit tonnage)
(maximum unit capacity x time x step_high)
(specific heat x dead band)
