Carrier 39E/ER - Manual (Page 11)

APPLICATION CONSIDERATIONS Table 6 — Motor Mounting Designation
Heat Gain from Electrical Motors — Some mis­
conceptions exist regarding the heat added to the air-
stream by central-station units having internally-
mounted motors versus units that have their motors
externally mounted. This topic can be found in the
Carrier System Design Manual, Part 1, Load Estimat­
ing. Typical values of the heat added by internally- and
externally-mounted motors over a lange of sizes and
motor heat generation are discussed. Briefly stated:
The central-station unit with externally-mounted
motors adds heat to the supply air which can be calculated
by using the formula'
Heat Added, Btuh = Bhp x 2545
The central-station unit with an internally-mounted
motor adds heat to the supply air which can be calculated
by using the formula
Bhp X 2545
Heat Added, Btuh
I Motor Efficiency
The additional heat that an internally-mounted motor
adds to the airstream compared to that of an externally-
mounted motor can be calculated by using the formula:
Additional Heat Added, Btuh
Bhp X 2545 (1 - % Motor Efficiency)
% Motor Efficiency
DISCHARGE
ARRANGEMENT
DRIVE AND ACCESS
DOOR HANDt
Left Right
Top Horizontal Front, THF F2 Fi
Bottom Horizontal Front, BHF Fl ^2
Upblast Front, UBF F2 Fl
Upblast Rear, UBR Fl F2
Downblast, DB Fl F2
Top Horizontal Rear,* THR Fl F2
Bottom Horizontal Rear,* BHR F2 Fl
'Vertical fan sections only
fSizes 48-90 use FI motor position for all discharges
NOTES
1. When ordering replacement motors, theconduit box MUST be
installed in the correct location on the motor, or there will be
interference and the motor will not fit into unit properly
2 In many cases the motor vendor supplies a motor with the
conduit box located on top of the motor
F2 FI
When the apparatus room is used as a plenum, the fan
motor and all other motors in the room are in the air-
stream. Therefore, even though the central-station unit
motors are externally mounted, they are still in the air-
stream and the same amount of heat is added as if
internally-mounted motors were used.
Additional Information which is useful in selecting
motors and drives is shown in Tables 6 through 14.
Table 7 — Typical Values of Full Load Amps at
460 Volts for Standard Motors*
MOTOR
HP
1800 RPM 3600 RPM
Framet ODP TEFC Frame ODP Frame TEFC
2 145T ___ 30 — ___ ___ ___
3 182T — 50 145T — 182T 4 1
5 184T 73 67 182T 69 184T 63
7.5 213T 105 9.8 184T 93 213T 95
10 215T 126 134 213T 130 215T 12 5
15 254T 20 0 180 215T 190 254T 183
20 256T 25 0 24.5 254T 23 0 256T 24 5
25 284T 31 5 32 0 256T 29 0 — —
30 286T 37 0 35 0 — — — —
40 324T 48 0 50.0 — — — —
50 326T 60 0 62.0 — — — —
60 364T 70 0 70 0 — — — —
75 365T 87.0 86 0 — — — —
100 404T 1160 — — — — —
100 405T — 1150 — — — —
OOP — Open Drip Proof
TEFC — Totally Enclosed Fan-Cooled
'Amps will be doubled for 230 volts
fTEFC, 1800 rpm motors use the same size frame as ODP,
1800 rpm motors
NOTES.
1 Frame sizes given above apply to motors for which standard
drives are available
2 Amp values are based on Magnetex Century-Electric motors
For data on other manufacturers, consult their catalog.
I 1