Trane RAUJ-C20, Installation, Operation And Maintenance Manual

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66 SS-SVX11K-EN
Power Wire Sizing and Protection Devices
Table 19. RAUJ power wire selections
Unit Size
(tons) Voltage
To Disconnect Switch (1S1)
To Main Terminal Block
Disconnect
Size
(amps)
Connector Wire
Range
Terminal Block
Size
(amps) Connector Wire Range
20, 30, 40
200/230
250
(1) #4-350 kcmil
335
(1) #6-350 MCM
380/415/460
100
(1) #14-1/0
335
(1) #6-350 MCM
575 100
(1) #14-1/0
335
(1) #6-350 MCM
50
200/230
400
(1) #1 - 600 kcmil OR(2)
#1 - 250 kcmil
335
(1) #6-350 MCM
380/415/460 250
(1) #4-350 kcmil
335
(1) #6-350 MCM
575 100
(1) #14-1/0
335
(1) #6-350 MCM
60
200/230
400
(1) #1 - 600 kcmil OR(2)
#1 - 250 kcmil
335
(1) #6-350 MCM
380/415/460
250
(1) #4-350 kcmil
335
(1) #6-350 MCM
575 250
(1) #4-350 kcmil
335
(1) #6-350 MCM
80 to 120 All - - 760
(2) #4-500 MCM
Table 20. 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
80 to 120 12 2 3000
Table 21. Control terminal blocks
Unit Size Control Terminal Blocks
20 to 60
7TB5 thru 7TB8, 6TB9
80 to 120 7TB5 thru 7TB8
Equations
To correctly size main power wiring for the unit, use
appropriate calculation(s) listed below.
L Lo oa ad d D De effiin niittiio on nss ffo orr C Ca allccu ulla attiio on nss
• 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
C Ca allccu ulla attiio on n — — M MC CA A,, M MO OP P,, a an nd d R RD DE E
• M MC CA A = (1.25 x LOAD 1) + LOAD 2 + LOAD 4
• M MO OP P = (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.
N No otte e:: 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.
• R RD DE E = (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.
N No otte e:: If the selected RDE is greater than selected MOP
value, select RDE value to equal MOP value.
C Ca allccu ulla attiio on n — — D Diisscco on nn ne ecctt S Sw wiittcch h S Siizziin ng g ((D DS SS S))
• DSS = 1.15 X (LOAD 1 + LOAD 2 + LOAD 4)
Field Installed Control Wiring
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