40
CAUJ-SVX01E-EN
WWAARRNNIINNGG
PPrrooppeerr FFiieelldd WWiirriinngg aanndd GGrroouunnddiinngg
RReeqquuiirreedd!!
FFaaiilluurree ttoo ffoollllooww ccooddee ccoouulldd rreessuulltt iinn ddeeaatthh oorr
sseerriioouuss iinnjjuurryy..
AAllll ffiieelldd wwiirriinngg MMUUSSTT bbee ppeerrffoorrmmeedd bbyy qquuaalliiffiieedd
ppeerrssoonnnneell.. IImmpprrooppeerrllyy iinnssttaalllleedd aanndd ggrroouunnddeedd
ffiieelldd wwiirriinngg ppoosseess FFIIRREE aanndd EELLEECCTTRROOCCUUTTIIOONN
hhaazzaarrddss.. TToo aavvooiidd tthheessee hhaazzaarrddss,, yyoouu MMUUSSTT ffoollllooww
rreeqquuiirreemmeennttss ffoorr ffiieelldd wwiirriinngg iinnssttaallllaattiioonn aanndd
ggrroouunnddiinngg aass ddeessccrriibbeedd iinn NNEECC aanndd yyoouurr llooccaall//
ssttaattee eelleeccttrriiccaall ccooddeess..
NNOOTTIICCEE
UUssee CCooppppeerr CCoonndduuccttoorrss OOnnllyy!!
FFaaiilluurree ttoo uussee ccooppppeerr ccoonndduuccttoorrss ccoouulldd rreessuulltt iinn
eeqquuiippmmeenntt ddaammaaggee aass uunniitt tteerrmmiinnaallss aarree nnoott
ddeessiiggnneedd ttoo aacccceepptt ootthheerr ttyyppeess ooff ccoonndduuccttoorrss..
See “Power Wire Sizing and Protection Devices,” p. 40
for field connection wire ranges for main power
terminal block 1TB1.
See Electrical Data tables for unit electrical data. The
electrical service must be protected from over current
and short circuit conditions in accordance with NEC
requirements. Protection devices must be sized
according to the electrical data on the nameplate.
• See Calculation — MCA, MOP, and RDE in “Wiring
Requirements,” p. 39 section to determine the
following:
– Electrical service wire size based on Minimum
Circuit Ampacity (MCA),
– Maximum Overcurrent Protection (MOP) device.
– Recommended Dual Element fuse size (RDE).
• A field supplied disconnect switch must be installed
at or near the unit in accordance with the National
Electrical Code (latest edition). See Calculation —
Disconnect Switch Sizing (DSS) in “Wiring
Requirements,” p. 39 section to determine the
correct size.
• Complete the unit’s power wiring connections onto
either the main terminal block 1TB1, or the factory
mounted non-fused disconnect switch 1S1, inside
the unit control panel. Refer to the customer
connection diagram that shipped with the unit for
specific termination points.
• Provide proper supply power (with over current
protection) to the Compressor unit and Air Handling
unit (“No Control”,“VAV”, and “Constant Volume”)
applications. For chilled water systems, provide a
properly sized power supply to the circulating
pump motor (EVP control applications). Be certain
that these components are properly grounded.
• Provide proper grounding for the unit in accordance
with local and national codes.
Power Wire Sizing and Protection Devices
Table 14. CAUJ power wire selections
Units
Sizes
(tons) Voltage
To Main Terminal Block 1T1
Terminal
Block Size
(amps)
Connector
Wire Range
20 to 60 All 175
(1) #14-2/0
80 to 120 All 175
(1) #12-2/0
Table 15. Control wire selections
Units Sizes
(tons)
Wire
Gauge
Ohms per
1000 feet
Max Wire
Length (ft)
All 18 8 500
All 16 5 1000
All 14 3 2000
All 12 2 3000
Table 16. Control terminal blocks
Unit Size Control Terminal Blocks
20 to 60 1TB2
80 to 120 1TB4
Equations
To correctly size main power wiring for the unit, use
appropriate calculation(s) listed below.
LLooaadd DDeeffiinniittiioonnss ffoorr CCaallccuullaattiioonnss
• LOAD 1: Current of largest motor (compr or fan
motor)
• LOAD 2: Sum of the currents of all remaining
motors
• LOAD 4: Control panel transformer and any other
load rated at 1A or more
CCaallccuullaattiioonn —— MMCCAA,, MMOOPP,, aanndd RRDDEE
• MMCCAA = (1.25 x LOAD 1) + LOAD 2 + LOAD 4
• MMOOPP = (2.25 x LOAD 1) + LOAD 2 + LOAD 4
Select a fuse rating equal to the MOP value. If the MOP
value does not equal a standard fuse size as listed in
NEC 240 - 6, select the next lower standard fuse rating.
NNoottee:: If selected MOP is less than the MCA, then select
the lowest standard maximum fuse size which is
equal to or larger than the MCA, provided the
selected fuse size does not exceed 800 amps.
• RRDDEE = (1.5 x LOAD 1) + LOAD 2 + LOAD 4
Select a fuse rating equal to the RDE value. If the RDE
value does not equal a standard fuse size as listed in
NEC 240 - 6 select the next higher standard fuse rating.
NNoottee:: If the selected RDE is greater than selected MOP
value, select RDE value to equal MOP value.
IInnssttaallllaattiioonn EElleeccttrriiccaall
To Next Page
Loading...
Need help?
General
