Trane RAUJ-C20, Installation, Operation And Maintenance Manual

Page: 109 / 132

SS-SVX11K-EN 109
N NO OT TIIC CE E
C Co om mp prre esssso orr D Da am ma ag ge e!!
E Ex xcce essssiiv ve e lliiq qu uiid d a accccu um mu ulla attiio on n iin n tth he e ssu uccttiio on n lliin ne ess
cco ou ulld d rre essu ulltt iin n cco om mp prre esssso orr d da am ma ag ge e..
D Do o n no ott a allllo ow w lliiq qu uiid d rre effrriig ge erra an ntt tto o e en ntte err tth he e ssu uccttiio on n
lliin ne e..
8. At the liquid line angle valve add as much R-410A
LIQUID as possible up to, but not exceeding, that
listed in
Table 33, p. 108 . Depending on conditions,
it could not be possible to add more than 60% of the
charge listed in the table. This will be adequate for
compressor startup. More charge will be added
after compressors are started. Use an accurate
scale to measure and record the preliminary
amount of R-410A added to each circuit.
9. Do not add refrigerant in the suction line at this
time to prevent excessive refrigerant in the low side
prior to compressor startup.
Compressor Start-Up
(All Systems)
Table 34. Minimum starting ambient temperature
Unit
Size
Minimum Starting Ambient (a) (°F)
Standard Units Low Ambient Units
With
HGBP
No
HGBP
With
HGBP No HGBP
20-60 45 40 10 0
80-120 45 40 10 0
(a) Minimum starting ambients in degrees F and is based on the unit
operating at minimum step of unloading and 5 mph wind across
condenser.
1. Review "Adding Preliminary Charge" section and
confirm all steps were completed.
N NO OT TIIC CE E
C Co om mp prre esssso orr D Da am ma ag ge e!!
F Fa aiillu urre e tto o ffo ollllo ow w iin nssttrru uccttiio on nss cco ou ulld d rre essu ulltt iin n
cco om mp prre esssso orr d da am ma ag ge e..
K Ke ee ep p ccrra an nkkcca asse e h he ea atte errss o on n w wh he en ne ev ve err rre effrriig ge erra an ntt iiss
iin n tth he e ssy ysstte em m..
IIff ccrra an nkkcca asse e h he ea atte errss h ha av ve e n no ott b be ee en n o on n w wiitth h
rre effrriig ge erra an ntt iin n tth he e ssy ysstte em m,, ttu urrn n tth he e ccrra an nkkcca asse e
h he ea atte errss o on n ffo orr a a m miin niim mu um m o off 2 24 4 h ho ou urrss b be effo orre e
sstta arrttiin ng g cco om mp prre esssso orrss..
N No otte e:: Initial compressor start-up is best done above
70°F outdoor temperature with ample evaporator
load (at least 70°F return air and 350 CFM/Ton)
N No otte e:: Table 34, p. 109 gives the minimum starting
temperatures for both "Standard" & "Low"
Ambient units
IIm mp po orrtta an ntt:: Do not attempt to charge the system with
the low ambient dampers and/or hot gas
bypass operating (if applicable). Disable
low ambient dampers in the "Open"
position (refer to the "Low Ambient
Damper Adjustment" section) and verify
hot gas bypass is not operating before
proceeding.
2. On units with dual circuits, work on only one circuit
at a time. See tables in Compressor Sequencing
section for the compressor sequencing and
Operating Principals chapter Component Location
illustrations for their location..
3. Compare the amount of preliminary charge added
in the proceeding section to the table in that section
for condensing unit and piping only. Up to 20%
more charge than listed in that table may be
required to fully charge the circuit, depending on
the evaporator design. Have adequate R-410A
available to complete charging as described in the
following steps.
4. Attach a thermocouple type temperature sensor on
the liquid line close to the liquid line service valve.
To insure an accurate liquid temperature reading,
clean the line where the sensor is attached. After
securing the sensor to the line, insulate the sensor
and line to isolate it from the ambient air.
5. Attach a set of service gauges onto the suction and
discharge gauge ports.
6. Check the low side pressure. The low pressure
cutout (4S3, 4S4) opens below 58 psig and closes
above 78 psig. If the low side pressure is less than
78 psig, refrigerant may need to be added to the
suction line before starting the compressor(s).
Slowly meter into the suction line only as much R–
410A as needed to make the low pressure cutout
from the VAPOR charging connection. If possible,
plan to use this entire refrigerant bottle on the same
unit in order to minimize fractionalization. Use an
accurate scale to measure and record the amount of
R-410A added.
W WA AR RN NIIN NG G
H Ha azza arrd do ou uss V Vo olltta ag ge e!!
F Fa aiillu urre e tto o d diisscco on nn ne ecctt p po ow we err b be effo orre e sse errv viicciin ng g cco ou ulld d
rre essu ulltt iin n d de ea atth h o orr sse erriio ou uss iin njju urry y..
D Diisscco on nn ne ecctt a allll e elle eccttrriicc p po ow we err,, iin nccllu ud diin ng g rre em mo otte e
d diisscco on nn ne eccttss b be effo orre e sse errv viicciin ng g.. F Fo ollllo ow w p prro op pe err
llo occkko ou utt//tta ag go ou utt p prro occe ed du urre ess tto o e en nssu urre e tth he e p po ow we err
cca an n n no ott b be e iin na ad dv ve errtte en nttlly y e en ne errg giizze ed d.. V Ve erriiffy y tth ha att n no o
p po ow we err iiss p prre esse en ntt w wiitth h a a v vo ollttm me ette err..
7. Switch the field supplied unit disconnect "OFF".
Open the unit control box and plug in the reset
relay (1K21 or 1K22) for the circuit being started
only.
8. This charging procedure is more accurate at higher
S Stta arrtt--U Up p