Trane Technologies CenTraVac CVHE, Installation, Operation And Maintenance Manual

Page: 62 / 108

62 CVHE-SVX005B-EN
N No otte ess::
• Verify PFCC voltage rating is greater than or
equal to the compressor voltage rating
stamped on the unit nameplate.
• Refer to the wiring diagrams that shipped
with the unit for specific PFCC wiring
information.
N NO OT TIIC CE E
M Mo otto orr D Da am ma ag ge e!!
F Fa aiillu urre e tto o w wiirre e P PF FC CC Css iin ntto o tth he e sstta arrtte err cco orrrre eccttlly y
cco ou ulld d cca au usse e m miissa ap pp plliicca attiio on n o off tth he esse e cca ap pa acciitto orrss
a an nd d rre essu ulltt iin n a a llo ossss o off m mo otto orr o ov ve errllo oa ad d p prro otte eccttiio on n
a an nd d ssu ub bsse eq qu ue en nttlly y cca au usse e m mo otto orr d da am ma ag ge e..
P PF FC CC Css m mu usstt b be e w wiirre ed d o on ne e o off ttw wo o w wa ay yss a ass ssh ho ow wn n a ass
e ex xp plla aiin ne ed d iin n tth he e ffo ollllo ow wiin ng g ffiig gu urre ess a an nd d
a acccco om mp pa an ny yiin ng g tte ex xtt ((O Op pttiio on n 1 1 a an nd d O Op pttiio on n 2 2))..
Figure 39. Option 1—PFCCs installed downstream of
starter contactor, upstream of current transformers
Power
Circuit
1
2
3
Fused
Disconnect
or Suitable
Breaker
Motor Starter
Contactor
Motor
Current
Transformer
Fuses
Enclosed
3-phase
Capacitor
Unit
W WA AR RN NIIN NG G
H Ha azza arrd do ou uss V Vo olltta ag ge e w w//C Ca ap pa acciitto orrss!!
F Fa aiillu urre e tto o d diisscco on nn ne ecctt p po ow we err a an nd d d diisscch ha arrg ge e
cca ap pa acciitto orrss 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 a an nd d d diisscch ha arrg ge e a allll m mo otto orr sstta arrtt//rru un n
cca ap pa acciitto orrss 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 nn no ott b be e iin na ad dv ve errtte en nttlly y e en ne errg giizze ed d.. F Fo orr v va arriia ab blle e
ffrre eq qu ue en nccy y d drriiv ve ess o orr o otth he err e en ne errg gy y sstto orriin ng g
cco om mp po on ne en nttss p prro ov viid de ed d b by y T Trra an ne e o orr o otth he errss,, rre effe err tto o
tth he e a ap pp prro op prriia atte e m ma an nu uffa accttu urre err’’ss lliitte erra attu urre e ffo orr
a allllo ow wa ab blle e w wa aiittiin ng g p pe erriio od dss ffo orr d diisscch ha arrg ge e o off
cca ap pa acciitto orrss.. V Ve erriiffy y w wiitth h a a C CA AT T IIIIII o orr IIV V v vo ollttm me ette err
rra atte ed d p pe err N NF FP PA A 7 70 0E E tth ha att a allll cca ap pa acciitto orrss h ha av ve e
d diisscch ha arrg ge ed d..
Simultaneously disconnect capacitors and load from
line power. If the capacitors are not switched offline
when the load is disconnected, they continue to add
capacitance to the electrical distribution system. A
leading power factor—too much capacitance—may
eventually develop. This overprotection causes poor
voltage regulation (i.e., voltage is high when the circuit
is unloaded, then drops as loads are added).
Figure 40. Option 2—PFCC wires routed through
current transformers
Power
Circuit
1
2
3
Fused
Disconnect
or Suitable
Breaker
Motor Starter
Contactor
Motor
Current
Transformer
Fuses
Enclosed
3-phase
Capacitor
Unit
Size motor overload protection to account for
capacitor-supplied current. Overloads are typically set
to measure the total current drawn by the motor. When
PFCCs are used, they become the source of part of that
current. If the current they provide is not registered by
the overload protectors, potentially damaging
amperage can reach the motor. The simplest way to
ensure that the overloads detect all current supplied to
the motor is to position the PFCCs upstream of the
current transformers as shown in the preceding figure
(Option 1). If the capacitor connection points are
downstream of the current transformers, route the
PFCC leads through the current transformers as shown
in the preceding figure (Option 2). This ensures that the
overloads register both line and capacitor-supplied
current.
Interconnecting Wiring
Typical equipment room conduit layouts with and
without unit-mounted starters are shown in the
following two figures.
IIm mp po orrtta an ntt:: The interconnecting wiring between the
starter panel, compressor, and control
panel is factory-installed with unit-mounted
starters. However, when a remote-mounted
starter is used, the interconnecting wiring
must be field-installed.
N No otte e:: Refer to starter submittal drawing for location of
incoming wiring to the starter.
P Po ow we err S Su up pp plly y W Wiirriin ng g