Operating Instructions and Installation Instructions

Installation and operation manual
7
EUWA(*)5~24KBZW1
Packaged air-cooled water chillers
4PW61653-1 – 07.2010
WATER CHARGE, FLOW AND QUALITY
For all versions
To assure proper operation of the unit a minimum water volume is
required in the system and the water flow through the evaporator
must be within the operation range as specified in the table.
Only for EUWAP, EUWAB versions
Connecting pressure gauges to the water circuit (field supply)
It is desirable to know the static height over the pump, for regulating
the water flow (refer to "Pump start up" on page 10). For this reason
you need to install pressure gauges or a differential pressure gauge
on the pressure ports.
Maximum allowed installation height in function of the water
volume
Make sure to respect following limitations:
If the EUWA is installed at the highest point of the system, then there
is no height difference to be considered.
If the EUWA is placed on a height level other than the highest point,
refer to figure 7 to read the maximum allowed height difference in
function of the water volume.
e.g.: If water volume=180 l, the maximum allowed installation height
difference is 9 m.
Setting the pre-pressure of the expansion vessel
The pre-pressure (Pg) on the expansion vessel has to be set before
filling the system with water or water/glycol solution in function of the
maximum installation height difference (H).
Use dry compressed air or nitrogen for this operation.
The pre-pressure (Pg) to be set is calculated as below:
Pg=(H/10+0.3) bar
H=Maximum installation height of the circuit above the EUWA unit (m)
Water quality specifications
Unit (Hp)
Minimum water
volume (l)
(*)
(*) a = cooling temperature difference (refer to "Defining the cooling temperature
differential" on page 15).
Minimum water flow
(l/min)
Maximum water flow
(l/min)
5 162/a 25 65
8 255/a 35 102
10 324/a 40 129
12 378/a 51 152
16 264/a 65 212
20 333/a 75 267
24 396/a 83 317
circulating
water
supply water
tendency if out
of criteria
Items to be controlled
pH at 25°C 6.8~8.0 6.8~8.0 corrosion + scale
Electrical
conductivity
[mS/m]
at 25°C
<40 <30 corrosion + scale
Chloride ion
[mg Cl
–
/l]
<50 <50 corrosion
Sulfate ion
[mg SO
4
2–
/l]
<50 <50 corrosion
M-alkalinity
(pH 4.8)
[mg CaCO
3
/l]
<50 <50 scale
Total hardness
[mg CaCO
3
/l]
<70 <70 scale
Calcium hardness
[mg CaCO
3
/l]
<50 <50 scale
Silica ion
[mg SiO
2
/l]
<30 <30 scale
Items to be referred to
Iron [mg Fe/l] <1.0 <0.3 corrosion + scale
Copper [mg Cu/l] <1.0 <0.1 corrosion
Sulfide ion
[mg S
2–
/l]
not detectable not detectable corrosion
Ammonium ion
[mg NH
4
+
/l]
<1.0 <0.1 corrosion
Remaining
chloride
[mg Cl/l] <0.3 <0.3 corrosion
Free carbide
[mg CO
2
/l]
<4.0 <4.0 corrosion
Stability index — — corrosion + scale
The chillers are only to be used in a closed water system.
Application in an open water circuit can lead to excessive
corrosion of the water piping.
If the water system is drained during some period, rinse
out the pump chamber with demineralised water. This to
prevent the impeller to be blocked by dried inpurities.
To do this, use the drain tap of the pump. Fill and empty the
pump a few times until the removed water is completely
clear. Keep the connections closed to prevent corrosion
and dirt entering the water system.
Use of glycol is allowed, but the amount should not exceed
40% of the volume. A higher amount of glycol may cause
damage to some hydraulic components.
1 2
3
4
1 Water out
2 Impeller
3 Water in
4 Drain tap
4PW61653-1_digital_EN.book Page 7 Thursday, August 26, 2010 1:49 PM