Water Heat Exchanger Maintenance; Refrigerant Volume; Characteristics Of R-410A - Danfoss AR05 017 Series Installation, Operation And Maintenance Instructions

Level 2
The two cleaning products can be used for any of the
following coil fi nishes: Cu/Cu, Cu/Al, Cu/Al with Polual,
Blygold and/or Heresite protection.
Clean the coil, using appropriate products.
We recommend TOTALINE products for coil cleaning:
Part No. P902 DT 05EE: traditional cleaning method
Part No. P902 CL 05EE: cleaning and degreasing.
These products have a neutral pH value, do not contain
phosphates, are not harmful to the human body, and can be
disposed of through the public drainage system.
Depending on the degree of fouling both products can be
used diluted or undiluted.
For normal maintenance routines we recommend using 1 kg
of the concentrated product, diluted to 10%, to treat a coil
2
surface of 2 m . This process can either be carried out using a
high-pressure spray gun in the low-pressure position. With
pressurised cleaning methods care should be taken not to
damage the coil fi ns. The spraying of the coil must be done:
• in the direction of the fi ns
• in the opposite direction of the air fl ow direction
• with a large diff user (25-30°)
• at a minimum distance of 300 mm from the coil.
It is not necessary to rinse the coil, as the products used are
pH neutral. To ensure that the coil is perfectly clean, we
recommend rinsing with a low water fl ow rate. The pH value
of the water used should be between 7 and 8.
WARNING: Never use pressurised water without a large
diff user. Do not use high-pressure cleaners for Cu/Cu and Cu/
Al coils.
Concentrated and/or rotating water jets are strictly
forbidden. Never use a fl uid with a temperature above 45°C to
clean the air heat exchangers.
Correct and frequent cleaning (approximately every three
months) will prevent 2/3 of the corrosion problems.
Protect the control box during cleaning operations.

16.7 - Water heat exchanger maintenance

Check that:
• the insulating foam is intact and securely in place.
• the cooler heaters are operating, secure and correctly
positioned.
• the water-side connections are clean and show no sign
of leakage.
30

16.8 - Refrigerant volume

The unit must be operated in cooling mode to fi nd out, if the
unit charge is correct, by checking the actual subcooling.
Following a small refrigerant leak a loss of refrigerant,
compared to the initial charge will be noticeable in the
cooling mode and aff ect the subcooling value obtained at
the air heat exchanger (condenser) outlet, but it will not be
noticeable in the heating mode.
IMPORTANT: It is therefore not possible to optimise the
refrigerant charge in the heating mode after a leak. The unit
must be operated in the cooling mode to check, if an
additional charge is required.

16.9 - Characteristics of R-410A

Saturated temperatures (°C) based on the relative pressure (in kPa)
Saturated Relative
temperature, °C pressure, kPa
-20 297
-19 312
-18 328
-17 345
-16 361
-15 379
-14 397
-13 415
-12 434
-11 453
-10 473
-9 493
-8 514
-7 535
-6 557
-5 579
-4 602
-3 626
-2 650
-1 674
0 700
1 726
2 752
3 779
4 807
5 835
6 864
7 894
8 924
9 956
10 987
11 1020
12 1053
13 1087
14 1121
15 1156
16 1192
17 1229
18 1267
19 1305
20 1344
21 1384
22 1425
23 1467
24 1509
AR05 units use high-pressure R-410A refrigerant (the unit
operating pressure is above 40 bar, the pressure at 35°C air
temperature is 50% higher than for R-22). Special equipment
must be used when working on the refrigerant circuit
(pressure gauge, charge transfer, etc.).
Installation, operation and maintenance instructions - VMGFE102
Saturated Relative
temperature, °C pressure, kPa
25 1552
26 1596
27 1641
28 1687
29 1734
30 1781
31 1830
32 1880
33 1930
34 1981
35 2034
36 2087
37 2142
38 2197
39 2253
40 2311
41 2369
42 2429
43 2490
44 2551
45 2614
46 2678
47 2744
48 2810
49 2878
50 2947
51 3017
52 3088
53 3161
54 3234
55 3310
56 3386
57 3464
58 3543
59 3624
60 3706
61 3789
62 3874
63 3961
64 4049
65 4138
66 4229
67 4322
68 4416
69 4512
70 4610