Water Heat Exchanger Maintenance; Variable Frequency Drive Maintenance; Characteristics Of R-410A; Check Of Power Factor Correction Capacitors - Carrier 30RQM 160 Installation, Operation And Maintenance Instructions

IMPORTANT: Never use a pressure water spray without a large
diffuser. Concentrated and/or rotating water jets are strictly
prohibited.
Never use a fluid with a temperature above 45°C to clean the
air heat exchangers.
Correct and frequent cleaning (approximately every three
months) will prevent two-thirds of corrosion problems. Protect
the electrics box during cleaning operations.

11.7 - Water heat exchanger maintenance

Check that:
• The insulation has not been detached or torn during
operations,
• The heaters and probes are operating and correctly
positioned in their support,
• The water-side connections are clean and show no sign of
leakage,
• The period inspections required by the local regulations
have been carried out.

11.8 - Variable frequency drive maintenance

CAUTION: Before any work on the variable drive, ensure that
the circuit is isolated and there is no voltage present (reminder:
capacitor discharge time: approximately 5 minutes after the
circuit breaker is opened). Only appropriately qualified
personnel are authorised to work on the variable frequency
drive.
In case of any alarm or persistent problem related to the variable
frequency drive, contact Carrier Service.
The variable drives fitted on 30RQM/30RQP units do not require
a dielectric test, even if being replaced: they are systematically
verified before delivery. Moreover, the filtering components
installed in the variable drive can falsify the measurement and
may even be damaged. If it is necessary to test the insulation of
the unit components (fan motors and pumps, cables, etc.), the
variable frequency drive must be disconnected from the power
circuit.
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11.9 - Characteristics of R-410A

See the table below.
Saturated temperatures based on the gauge pressure (in kPa)
Pressure Pressure
Saturated Saturated
Temp. Temp.
gauge gauge
-20 297 4 807
-19 312 5 835
-18 328 6 864
-17 345 7 894
-16 361 8 924
-15 379 9 956
-14 397 10 987
-13 415 11 1020
-12 434 12 1053
-11 453 13 1087
-10 473 14 1121
-9 493 15 1156
-8 514 16 1192
-7 535 17 1229
-6 557 18 1267
-5 579 19 1305
-4 602 20 1344
-3 626 21 1384
-2 650 22 1425
-1 674 23 1467
0 700 24 1509
726 1596
1 26
2 752 25 1552
3 779 27 1641
Aquasnap 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
measurement, charge transfer, etc.).

11.10 - Check of power factor correction capacitors

The verification consists in measuring input current of each
capacitor bank. Check shall be done using a true RMS meter
reading:
Check per phase current delivered by each capacitor and
compare it to nominal values. In case of capacitance losses or
unbalance, the capacitors must be replaced.
Ensure that the current through the capacitor doesn't exceed
1.3xIr. A higher value may indicate heavy presence of harmonics,
that will impact the lifetime of the capacitor.
Absence of current despite capacitor is energized is an indication
that there is a defect. Confirmation shall be done by removing
the capacitors and checking the underside
Faulty
Pressure Pressure
Saturated Saturated
Temp. temp.
gauge gauge
28 1687 52 3088
29 1734 53 3161
30 1781 54 3234
31 1830 55 3310
32 1880 56 3386
33 1930 57 3464
34 1981 58 3543
35 2034 59 3624
36 2087 60 3706
37 2142 61 3789
38 2197 62 3874
39 2253 63 3961
40 2311 64 4049
41 2369 65 4138
42 2429 66 4229
43 2490 67 4322
44 2551 68 4416
45 2614 69 4512
46 2678 70 4610
47 2744
48 2810
2878
49
50 2947
51 3017
Correct