Trane RAUJ-C20, Installation, Operation And Maintenance Manual

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110 SS-SVX11K-EN
outdoor temperatures. If the outdoor temperature is
less than 80°F, temporarily disable the fan pressure
control switches (4S11, 4S12) or (4S7, 4S8) on 80 -
120 Ton units. To do this, refer to unit wiring
diagrams and disconnect the wires between the
switches and the terminal strip.
9. Switch the RAUJ 115 volt (1S2) control circuit
switch "ON". Close the control box and then switch
the field supplied unit disconnect "ON". Unit power
should be off no longer than 30 minutes to prevent
refrigerant migration to compressor sumps. If
power is off for longer than 30 minutes, allow time
for crankcase heaters to drive refrigerant from
compressor sumps before starting compressors.
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..
10. Verify that oil levels are near or above the top of all
compressor sight glasses.
W WA AR RN NIIN NG G
L Liiv ve e E Elle eccttrriicca all C Co om mp po on ne en nttss!!
F Fa aiillu urre e tto o ffo ollllo ow w a allll e elle eccttrriicca all ssa affe etty y p prre ecca au uttiio on nss
w wh he en n e ex xp po osse ed d tto o lliiv ve e e elle eccttrriicca all cco om mp po on ne en nttss cco ou ulld d
rre essu ulltt iin n d de ea atth h o orr sse erriio ou uss iin njju urry y..
W Wh he en n iitt iiss n ne ecce essssa arry y tto o w wo orrkk w wiitth h lliiv ve e e elle eccttrriicca all
cco om mp po on ne en nttss,, h ha av ve e a a q qu ua alliiffiie ed d lliicce en nsse ed d e elle eccttrriicciia an n
o orr o otth he err iin nd diiv viid du ua all w wh ho o h ha ass b be ee en n p prro op pe errlly y ttrra aiin ne ed d
iin n h ha an nd dlliin ng g lliiv ve e e elle eccttrriicca all cco om mp po on ne en nttss p pe errffo orrm m
tth he esse e tta asskkss..
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 b be ello ow w cco ou ulld d rre essu ulltt iin n
cco om mp prre esssso orr d da am ma ag ge e..
IIm mp prro op pe err p po ow we err p ph ha assiin ng g w wiillll cca au usse e cco om mp prre esssso orr tto o
rru un n b ba acckkw wa arrd dss.. C Co om mp prre esssso orr cco ou ulld d b be e rru un nn niin ng g
b ba acckkw wa arrd dss iiff iitt iiss n no oiissy y,, llo ow w ssiid de e ssh he ellll g ge ettss h ho ott,,
ssu uccttiio on n p prre essssu urre e d do oe ess n no ott d drro op p w wiitth hiin n 5 5 sse ecco on nd dss
a afftte err sstta arrttu up p,, a an nd d cco om mp prre esssso orr o on nlly y d drra aw wss ½ ½
e ex xp pe ecctte ed d a am mp pss.. S Stto op p tth he e cco om mp prre esssso orr iim mm me ed diia atte elly y
a an nd d h ha av ve e a a q qu ua alliiffiie ed d e elle eccttrriicciia an n o orr tte ecch hn niicciia an n
p prro op pe errlly y ttrra aiin ne ed d iin n 3 3 p ph ha asse e p po ow we err cco orrrre ecctt tth he e
w wiirriin ng g..
11. Start the first step compressor only.
a. If the compressor and condenser fans do not
start, the field power wiring to the RAUJ unit
could be improperly phased. A main unit power
phase protection module (1U3) is located in the
RAUJ control box and interrupts control circuit
power when improperly phased field power is
detected.
• CSHD compressors (used in 20 to 60 ton
units) are not equipped with electronic
modules and do not have individual
compressor phase protection.
• CSHN compressors (used in 80 to 120 ton
units) are individually equipped with
compressor protection modules (381U1,
382U2, 383U3, 384U4, 385U5, 386U6)
located in the compressor junction boxes.
These modules include phase, voltage,
overcurrent, and over temperature
protection. If CSHN compressors are started
with reversed phasing, the module output
relay will open in about 6 seconds. Module
output relays are wired in series with the
unit 115 volt control circuit reset relays
(1K21, 1K22). When any module output relay
opens, the circuit reset relay latches closed
and circuit operation is locked out. Note:
Refer to the Service & Maintenance section
of this manual or COM-SVN01*-EN for
further discussion regarding other potential
compressor protection module faults.
b. As soon as a compressor starts, verify correct
rotation. If a scroll compressor is allowed to run
backwards for even a very short period of time,
internal compressor damage could occur and
compressor life could be reduced. When
rotating backwards scroll compressors make a
loud noise, do not pump, draw about 1/2
expected amps, and the low side shell gets hot.
Immediately shut off a compressor rotating
backwards.
c. Check condenser fans for proper rotation. As
viewed from the top of the unit, the correct
rotation direction is clockwise.
d. If some or all of the fans are rotating backward,
follow steps outlined in Motors Rotating
Backwards section. Once complete, continue
steps below.
e. Start the remaining circuit compressor(s). Verify
correct rotation. Incorrect rotation is noisy,
compressor draws about ½ expected amps, and
the low side shell gets hot. Immediately shut off
any compressors rotating backwards.
f. After allowing 10 minutes for circuit operation
to stabilize at full load, check the liquid
temperature and discharge pressure. Plot on
Figure 74, p. 112 . Expect the operating point to
be in the "Add charge" portion of the chart. The
remainder of the circuit charge will be added in
the following steps.
S Stta arrtt--U Up p