Power Supply Wiring
56
CVHH-SVX001A-EN
Option 1—PFCCs installed dow nstream of
starter contactor, upstream of current
transformers.
N ot e: Graphic labels (show n above) are used for CE
application only.
Im port ant :
•
Before servicing, disconnect all pow er sources and
allow at least 30 m inutes for capacitors to discharge.
•
All electrical enclosures—unit or rem ote—are IP2X.
Sim ultaneously disconnect capacitors and load from line
pow er. If the capacitors are not sw itched offline w hen the
load is disconnected, they continue to add capacitance to
the electrical distribution system . A leading pow er
factor—too m uch capacitance—m ay eventually develop.
This overprotection causes poor voltage regulation (i.e.,
voltage is high w hen the circuit is unloaded, then drops as
loads are added).
Option 2—PFCC w ires routed through current
transformers.
Size m otor overload protection to account for capacitor-
supplied current. Overloads are typically set to m easure
the total current draw n by the m otor. When PFCCs are
used, they becom e the source of part of that current. If the
current they provide is not registered by the overload
protectors, potentially dam aging am perage can reach the
m otor. The sim plest way to ensure that the overloads
detect all current supplied to the m otor is to position the
PFCCs upstream of the current transform ers as show n in
the preceding figure. If the capacitor connection points are
dow nstream of the current transform ers, route the PFCC
leads through the current transform ers as show n in the
follow ing figure. This ensures that the overloads register
both line and capacitor-supplied current.
Interconnecting Wiring
Typical equipm ent room conduit layouts w ith and w ithout
unit-m ounted starters are show n in
Figure 30
and
Figure 31
.
Im port ant :
The interconnecting w iring betw een the
starter panel, com pressor, and control
panel is factory-installed w ith unit-m ounted
starters. How ever, w hen a rem ote-m ounted
starter is used, the interconnecting w iring
m ust be field-installed.
N ot e: Refer to starter subm ittal draw ing for location of
incom ing w iring to the starter.
WARNING
Hazardous Voltage w / Capacitors!
Failure to disconnect power and discharge capacitors
before servicing could result in death or serious injury.
Disconnect all electric power, including remote
disconnects and discharge all motor start/ run
capacitors before servicing. Follow proper lockout/
tagout procedures to ensure the pow er cannot be
inadvertently energized. For variable frequency drives
or other energy storing components provided by Trane
or others, refer to the appropriate manufacturer’s
literature for allowable w aiting periods for discharge of
capacitors. Verify w ith an appropriate voltmeter that all
capacitors have discharged.
For additional information regarding the safe discharge of
capacitors, see PROD-SVB06* -EN
X39003892001A
Mot or
Fuses
Enclosed
3- phase
capacit or
unit
Fused
disconnect
or suit able
br eaker
Pow er
cir cuit
1
2
3
Cur r ent
t ransfor m er
Mot or st ar t er
cont act or
Summary of Contents for CVHH
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