United Technologies Carrier 30RQM 160, Installation, Operation And Maintenance Instructions

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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.
11.9 - Characteristics of R-410A
11.9.1 - See the table below.
Saturated temperatures based on the gauge pressure (in kPa)
Saturated Temp.
Pressure
gauge
Saturated Temp.
Pressure
gauge
Saturated Temp.
Pressure
gauge
Saturated
temp.
Pressure
gauge
-20 297 4 807 28 1687 52 3088
-19 312 5 835 29 1734 53 3161
-18 328 6 864 30 1781 54 3234
-17 345 7 894 31 1830 55 3310
-16 361 8 924 32 1880 56 3386
-15 379 9 956 33 1930 57 3464
-14 397 10 987 34 1981 58 3543
-13 415 11 1020 35 2034 59 3624
-12 434 12 1053 36 2087 60 3706
-11 453 13 1087 37 2142 61 3789
-10 473 14 1121 38 2197 62 3874
-9
493
15
1156
39
2253
63
3961
-8 514 16 1192 40 2311 64 4049
-7 535 17 1229 41 2369 65 4138
-6 557 18 1267 42 2429 66 4229
-5
579
19
1305
43
2490
67
4322
-4 602 20 1344 44 2551 68 4416
-3 626 21 1384 45 2614 69 4512
-2 650 22 1425 46 2678 70 4610
-1
674
23
1467
47
2744
0 700 24 1509 48 2810
1 726 26 1596 49 2878
2 752 25 1552 50 2947
3
779
27
1641
51
3017
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
Defective Correct
11 - STANDARD MAINTENANCE
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