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Route thermostat cable or equivalent single leads of col-
ored wire from subbase terminals to low-voltage connec-
tions on unit (shown in Fig. 11) as described in Steps 1 - 4
below.
1. If unit is mounted on roof curb and accessory thru-the-
curb service plate connection is used, route wire through
connection plate.
2. Pass control wires through the hole provided on unit
(see connection D in Connection Sizes table in Fig. 7).
3. Feed wires through the raceway built into the corner post
to the 24-v barrier located on the left side of the control
NOMINAL
UNIT
IFM
VOLTAGE
48TJ
TYPE
(60 Hz)
208/230
(3 phase)
008
460
(7
1
⁄
Tons)
(3 phase)
2
575
(3 phase)
208/230
(3 phase)
009
460
(8
1
⁄
Tons)
(3 phase)
2
575
(3 phase)
208/230
(3 phase)
012
460
(10 Tons)
(3 phase)
575
(3 phase)
208/230
(3 phase)
014
460
(12
1
⁄
Tons)
(3 phase)
2
575
(3 phase)
LEGEND
FLA
— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM
— Indoor (Evaporator) Fan Motor
LRA
— Locked Rotor Amps
MCA
— Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC
— National Electrical Code
OFM
— Outdoor (Condenser) Fan Motor
RLA
— Rated Load Amps
UL
— Underwriters' Laboratories
*Used to determine minimum disconnect size per NEC.
†Fuse or HACR circuit breaker.
NOTES:
1. In compliance with NEC requirements for multimotor and combi-
nation load equipment (refer to NEC Articles 430 and 440), the
overcurrent protective device for the unit shall be fuse or HACR
breaker. Canadian units may be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply volt-
age is greater than 2%. Use the following formula to determine
the percent voltage imbalance.
% Voltage Imbalance
max voltage deviation from average voltage
= 100 x
average voltage
Table 2 — Electrical Data
VOLTAGE
COMPR
RANGE
(ea)
Min
Max
RLA
LRA
Std
187
254
13.6
73.4
Std
414
508
6.2
37.7
Std
518
632
4.9
31.0
Std
187
254
15.8
92.0
Std
414
508
7.4
46.0
Std
518
632
5.9
44.0
Std
187
254
17.9
110.0
Alt
Std
414
508
8.6
55.0
Alt
Std
518
632
6.4
44.0
Alt
Std
187
254
23.0
146.0
Alt
Std
414
508
10.4
73.0
Alt
Std
518
632
8.3
58.4
Alt
box. See Fig. 12. The raceway provides the UL-required
(Underwriters' Laboratories) clearance between high- and
low-voltage wiring.
4. Connect thermostat wires to screw terminals on low-
voltage connection board.
HEAT ANTICIPATOR SETTINGS — Set heat anticipator
settings at .14 amp for the first stage and .20 amp for second-
stage heating.
OFM
COMBUSTION
IFM
(ea)
FAN MOTOR
Hp
FLA
FLA
FLA
1
⁄
1.4
5.8
.57
4
1
⁄
0.8
2.6
.30
4
1
⁄
0.8
2.6
.30
4
1
⁄
1.4
5.8
.57
4
1
⁄
0.8
2.6
.30
4
1
⁄
0.8
2.6
.30
4
5.8
1
⁄
1.4
.57
4
7.5
2.6
1
⁄
0.8
.30
4
3.4
2.6
1
⁄
0.8
.30
4
3.4
10.6
1
⁄
1.4
.57
4
15.0
4.8
1
⁄
0.8
.30
4
7.4
4.8
1
⁄
0.8
.30
4
7.4
EXAMPLE: Supply voltage is 460-3-60.
NOTE: The 575-v 48TJ008-014 units are UL, Canada, only.
Determine maximum deviation from average voltage.
(AB) 457 - 452 = 5 v
(BC) 464 - 457 = 7 v
(AC) 457 - 455 = 2 v
Maximum deviation is 7 v.
Determine percent voltage imbalance.
% Voltage Imbalance = 100 x
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
9
DISCONNECT
POWER SUPPLY
SIZE*
MCA
MOCP†
FLA
39.2/39.2
45/45
41/41
18.0
25
19
14.2
20
15
44.2/44.2
50/50
46/46
20.7
25
22
16.5
20
17
48.9/48.9
60/60
51/51
50.6/50.6
60/60
53/53
23.4
30
24
24.2
30
25
17.6
20
18
18.2
20
19
65.2/65.2
80/80
68/68
69.6/69.6
80/80
73/73
29.6
35
31
32.2
35
34
23.6
30
25
25.7
35
27
AB = 452 v
BC = 464 v
AC = 455 v
452 + 464 + 455
Average Voltage =
3
1371
=
3
= 457
7
457
= 1.53%
LRA
194/194
99
81
231/231
116
107
267/267
286/286
134
173
107
139
383/383
406/406
192
203
154
163
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