Trane INTELLIPAK ™ ™ ™ ™ ™ Commercial Single-Zone Rooftop Air Conditioners with CV or VAV Control - Manual (Page 45)

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Power Wire Sizing and Protection Device Equations (Continued)
RDE = (1.5 x LOAD 1) + LOAD 2 + LOAD 3 + LOAD 4
The selected RDE value will be the larger of the cooling mode RDE value or the heating mode RDE value calculated above.
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.
Note: If the selected RDE is greater than the selected MOP value, then select the RDE value to equal the MOP
value.
B. Dual Source Power units (200V and 230V)
These units will have two circuit values shown on the nameplate. The first circuit value will be the refrigeration (cooling mode)
values calculated using calculation #1 above. The second set of circuit values shown on the nameplate will be for the electric
heating circuit as follows.
MCA = (1.25 x LOAD 3) MOP = (1.25 x LOAD 3)
Select a fuse rating for the electric heating circuit that’s equal to the MOP value obtained in the equation above. If the MOP
value does not equal a standard fuse size as listed in NEC 240 - 6, select the next lower standard fuse rating (see note be-
low for exception).
Note: If selected MOP is less than the MCA obtained in the equation above, 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.
RDE = LOAD 3
Select a fuse rating for the electric heating circuit that’s 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.
Note: If the selected RDE is greater than the selected MOP value, then select the RDE value to equal the MOP
value.
Disconnect Switch Sizing (DSS)
Calculation #1 - SX, SF, SA, SL, or SS Single Power Source Units
DSS = 1.15 X (LOAD 1 + LOAD 2 + LOAD 4)
Calculation #2 - All SEH_ Single Power Source Units
DSS = 1.15 X (LOAD 3 + Supply Fan FLA + Exhaust Fan FLA)
PLUS
DSS = 1.15 X (LOAD 1 + LOAD 2 + LOAD 4)
Use the larger value of the two calculations to size the electrical service.
Calculation #3 - SEHF (200/230 Volt) 20 - 75 Ton Dual Power Source Units
DSS = 1.15 X LOAD3 for the Electric heater AND Calculation #1 for the Refrigeration Components