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10
LEGEND AND NOTES FOR TABLE 2
LEGEND
*Heater capacity (kW) is based on heater voltage of 208, 240, 480, and 575-v. If
power distribution voltage varies from rated heater voltage, heater kW will vary
accordingly.
†Used to determine minimum disconnect per NEC.
NOTES:
1. In compliance with NEC requirements for multimotor and combination load
equipment (refer to NEC Articles 430 and 440), the overcurrent protective
device for the unit shall be fuse or HACR breaker.
2.
Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater
than 2%. Use the following formula to determine the percent of voltage
imbalance.
% Voltage Imbalance
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
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 of voltage imbalance.
This amount of phase imbalance is satisfactory as it is below the maximum
allowable 2%.
3. Non-fused disconnect switch cannot be used when rooftop unit electrical rat-
ings exceed 80 amps.
Table 3 — Electric Heater Usage
NOTES:
1. The rated heater voltage is 240, 480, and 575 v. If power distribution voltage varies from rated heater voltage, heater kW vary accordingly.
2. To determine heater kW at voltages other than those shown in table, use the following formula:
Heater kW new = Heater kW rated x (unit power distribution voltage / rated heater voltage)
2
As an example:
For a 16 kW heater rated at 240 v with a power distribution voltage of 215 v
kW new = 16 kW (215/240)
2
kW new = 12.8 kW (rating at 215 v)
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
= 100 x
max voltage deviation from average voltage
average voltage
Average Voltage =
452 + 464 + 455
3
=
1371
3
=
457
% Voltage Imbalance
= 100 x
7
457
= 1.53%
IMPORTANT: If the supply voltage phase imbalance is more than 2%, con-
tact your local electric utility company immediately.
UNIT
50HJ
VOLTAGE
(60 Hz)
ACCESORY
kW
ACCESSORY HEATER
PART NUMBER
CRHEATER---A00
ACCESSORY SINGLE POINT BOX
PART NUMBER
CRSINGLE---A00
008
208/230/240
(3 phase)
7.8/ 9.6/10.4
017
006
12.0/14.7/16.0
010
006
18.6/22.8/24.8
011
007
24.0/29.4/32.0
012
007
31.8/39.0/42.4
012+017
009
460/480
(3 phase)
12.8/13.9
016
006
15.2/16.5
013
006
25.6/27.8
014
006
30.4/33.0
015
006
38.4/41.7
014+016
008
575
(3 phase)
17.0
018
006
34.0
019
006
009
208/230/240
(3 phase)
7.8/ 9.6/10.4
017
011
12.0/14.7/16.0
010
011
18.6/22.8/24.8
011
012
24.0/29.4/32.0
012
012
31.8/39.0/42.4
012+017
015
460/480
(3 phase)
12.8/13.9
016
011
15.2/16.5
013
011
25.6/27.8
014
011
30.4/33.0
015
011
38.4/41.7
014+016
014
575
(3 phase)
17.0
018
011
34.0
019
011
012
208/230/240
(3 phase)
7.8/ 9.6/10.4
017
011
12.0/14.7/16.0
010
012
24.0/29.4/32.0
012
012
31.8/38.9/42.4
012+017
015
37.5/46.0/50.0
010+012
015
460/480
(3 phase)
12.8/13.9
016
011
15.2/16.5
013
011
30.4/33.0
015
011
38.4/41.7
014+016
014
46.0/50.0
013+015
014
575
(3 phase)
17.0
018
011
34.0
019
011
51.0
018+019
014
014
208/230/240
(3 phase)
7.8/ 9.6/10.4
017
012
12.0/14.7/16.0
010
012
24.0/29.4/32.0
012
012
31.8/38.9/42.4
012+017
015
37.5/46.0/50.0
010+012
015
460/480
(3 phase)
12.8/13.9
016
011
15.2/16.5
013
011
30.4/33.0
015
011
38.4/41.7
014+016
014
46.0/50.0
013+015
014
575
(3 phase)
17.0
018
011
34.0
019
014
51.0
018+019
014