Trane Flex II Series Installation Operation & Maintenance page 14

7.3 WATER TREATMENT
Before putting the unit into operation, clean the hydraulic circuit. Dirt, scales, corrosion residue and other extraneous
material can accumulate inside the heat exchanger and reduce its heat exchanging capacity. Pressure drops can
increase, as well, thus reducing water flow. Proper water treatment therefore reduces the risk of corrosion, erosion,
scaling, etc. The most appropriate water treatment must be determined locally, according to the type of system and to
the local characteristics of the process water.
Trane is not responsible for damage to or malfunctioning of equipment caused by failure to treat water or by improperly
treated water
Acceptable water quality limits
PH (25°C) 6,8÷8,0
Electrical conductivity
< 800
S/cm (25°C)
Chloride ion
< 200
(mg Cl - / l)
Sulphate ion
< 200
(mg SO 24- / l)
Alkalinity
< 100
(mg CaCO 3 / l)
7.4 PRECAUTION AGAINST FROST RISK OF THE HYDRAULIC PIPES
It is necessary to insulate pipes in the plant to avoid extreme heat loss and to protect them from weather conditions.
The problem of water pipes freezing could appear in two different situations:
1. Stand by, with mode on, but electrically connected: in this case, the unit has frost resistances, which protect the
weather locally contained in the exchangers and in the pipes from ice formation. These resistances do not guarantee
the protection against the frost in the outdoor connection pipes, to be prevented by frost protection systems. Trane
suggest to insert frost thermostatic resistances on every outdoor pipes. In the following table there are the indicative
electric power per pipe linear meter
Heating cable required power
dn inch
8
1/4"
10
3/8"
15
1/2"
20 3/4"
25
1"
40
1" 1/2
50
2"
65 2" 1/2
80 3"
100
4"
125
5"
150 6"
2. Electrically unconnected unit: in this case the frost resistances of the unit could not guarantee the protection. It is
necessary to add the correct glycol quantity indicated in the chapter: "ethylene glycol correction table" (§12.1).
Please consult Trane service for % of glycol required.
Total Hardness
< 200
(mg CaCO 3 / l)
Iron (mg Fe / l)
< 1.0
Sulfur ion
None
(mg S 2- / l)
Ammonium ion
< 1.0
(mg NH 4+ / l)
Silica
< 50
(mg SiO 2 / l)
W / m
5
5
5
10
13
30
50
80
120
200
300
450
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