Carrier 50HJ015-025, Installation, Start-Up And Service Instructions Manual

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10
LEGEND
*Heater capacity (kW) is based on heater voltage of 208 v, 240 v,
480 v, and 575 v. Heaters are rated at 240 v, 480 v, or 575 v. If
power distribution voltage to unit varies from rated heater voltage,
heater kW will vary accordingly.
†Fuse or HACR circuit breaker.
**Heaters are field installed only.
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 of voltage imbalance.
% Voltage Imbalance
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
= 457
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 = 100 x
= 1.53%
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
3. MCA calculation for units with electric heaters over 50 kW =
(1.25 x IFM amps) + (1.00 x heater FLA).
Table 3 — Electric Resistance Heater Data
*Maximum number of stages using accessory low-ambient kit or head pressure control device and low-ambient kit.
NOTE: Heaters are rated at 240, 480, and 575 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
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
7
457
UNIT
50HJ
HEATER kW
HEATER
STAGES
% HEAT
PER
STAGE
MAXIMUM
STAGES*
MINIMUM
HEATER AMPS
Unit Voltages Heating Cfm
208 230 240 460 480 575 600 Cfm L/s 208 230 240 460 480 575 600
015
14 17 19 14 15 — — 1 100 1
3750 1770
39.3 43.4 45.3 17.2 17.9 — —
26 31 34 30 32 — — 2 50/50 2 71.3 78.9 82.3 37.3 39.0 — —
42 52 56 50 55 37 40 2 33/67 3 117.0 129.4 135.0 63.3 66.1 37.0 38.6
017
26 31 34 30 32 — — 2 50/50 2
3750 1770
71.3 78.8 82.3 37.3 39.0 — —
42 52 56 50 55 — — 2 33/67 3 117.0 129.4 135.0 63.3 66.1 — —
56 69 75 73 80 — — 2 50/50 4 155.9 172.4 179.9 92.0 96.0 — —
025
26 31 34 30 32 — — 2 50/50 2
5000 2360
71.3 78.8 82.3 37.3 39.0 — —
42 52 56 50 55 — — 2 33/67 3 117.0 129.4 135.0 63.3 66.1 — —
56 69 75 73 80 — — 2 50/50 4 155.9 172.4 179.9 92.0 96.0 — —