Legend And Notes For Table 2; Electric Heater Usage - Carrier 50HJ008 Installation, Start-Up And Service Instructions Manual

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
*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
max voltage deviation from average voltage
= 100 x
average voltage
UNIT VOLTAGE ACCESORY
50HJ (60 Hz)
7.8/ 9.6/10.4
12.0/14.7/16.0
208/230/240
18.6/22.8/24.8
(3 phase)
24.0/29.4/32.0
31.8/39.0/42.4
12.8/13.9
008
15.2/16.5
460/480
25.6/27.8
(3 phase)
30.4/33.0
38.4/41.7
575
(3 phase)
7.8/ 9.6/10.4
12.0/14.7/16.0
208/230/240
18.6/22.8/24.8
(3 phase)
24.0/29.4/32.0
31.8/39.0/42.4
12.8/13.9
009
15.2/16.5
460/480
25.6/27.8
(3 phase)
30.4/33.0
38.4/41.7
575
(3 phase)
7.8/ 9.6/10.4
12.0/14.7/16.0
208/230/240
24.0/29.4/32.0
(3 phase)
31.8/38.9/42.4
37.5/46.0/50.0
12.8/13.9
012
15.2/16.5
460/480
30.4/33.0
(3 phase)
38.4/41.7
46.0/50.0
575
(3 phase)
7.8/ 9.6/10.4
12.0/14.7/16.0
208/230/240
24.0/29.4/32.0
(3 phase)
31.8/38.9/42.4
37.5/46.0/50.0
12.8/13.9
014
15.2/16.5
460/480
30.4/33.0
(3 phase)
38.4/41.7
46.0/50.0
575
(3 phase)
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)
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)

LEGEND AND NOTES FOR TABLE 2

Table 3 — Electric Heater Usage
ACCESSORY HEATER
PART NUMBER
kW
CRHEATER---A00
17.0
34.0
17.0
34.0
17.0
34.0
51.0
17.0
34.0
51.0
Example: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =
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.
% Voltage Imbalance
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%, con-
tact your local electric utility company immediately.
3. Non-fused disconnect switch cannot be used when rooftop unit electrical rat-
ings exceed 80 amps.
017
010
011
012
012+017
016
013
014
015
014+016
018
019
017
010
011
012
012+017
016
013
014
015
014+016
018
019
017
010
012
012+017
010+012
016
013
015
014+016
013+015
018
019
018+019
017
010
012
012+017
010+012
016
013
015
014+016
013+015
018
019
018+019
2
10
452 + 464 + 455
3
1371
=
3
= 457
7
= 100 x
457
= 1.53%
ACCESSORY SINGLE POINT BOX
PART NUMBER
CRSINGLE---A00
006
006
007
007
009
006
006
006
006
008
006
006
011
011
012
012
015
011
011
011
011
014
011
011
011
012
012
015
015
011
011
011
014
014
011
011
014
012
012
012
015
015
011
011
011
014
014
011
014
014