Carrier 50HJQ016 Installation, Start-Up And Service Instructions Manual page 20

ACCESSORY/FIOP UNIT SIZE
Electric Heaters
EconoMi$er
Glycol Coil
LEGEND
FIOP — Factory-Installed Option
*Do not operate unit with electric heat at this cfm. Operation at this
cfm is below electric heat required minimum cfm.
†Do not operate unit at this cfm. Operation at this cfm is above unit
maximum cfm limit.
Table 11 — Fan Rpm at Motor Pulley Settings* (Factory-Supplied Drives)
UNIT 50HJQ
0
014
†
(208/230, 460 v)
014
1462
(575 v)
016 †
*Approximate fan rpm shown.
†Due to belt and pulley size, pulley cannot be set to this number of
turns open.
DEFROST CYCLE — When the temperature of the outdoor
coil drops below 28 F as sensed by the defrost thermostat (DFT
or DFT2), the defrost timer starts. At the end of a timed period
(factory set at 30 minutes, field set at 50 or 90 minutes), the de-
frost cycle will begin. The defrost board energizes terminals O
and W2, energizes the defrost relay (DR), deenergizes the re-
versing valve solenoids (RVS1 and RVS2), and energizes the
electric heat. The outdoor-fan motor will stop.
The unit continues to defrost either until the coil temperature
as measured by DFT1 or DFT2 reaches 65 F, or until unit com-
pletes a 10-minute defrost cycle. See Fig. 31 for DFT location.
During the Defrost mode, when a circuit defrost, RVS will
oscillate between heating and cooling modes until defrost
mode is complete. This will prevent the head pressure from
getting too high.
At the end of the defrost cycle, the electric heaters (if appli-
cable) will be deenergized, the reversing valve solenoids will
be energized, and the outdoor fans will start.
A freeze protection thermostat (FPT) is located on the
indoor coil. It detects frost build-up and turns of the compres-
sor(s), allowing the coil to clear. Once frost has melted, the
compressor can be reenergized.
AUTOMATIC CHANGEOVER — When the system selec-
tion switch is set at AUTO. position, unit automatically changes
from heating operation to cooling operation when the tempera-
ture of the conditioned space rises to the cooling lever setting.
When the temperature of the conditioned space falls to the heat-
ing lever setting, unit automatically changes from cooling to
heating operation (with a 3 F deadband in between).
Table 10 — Accessory/FIOP Static Pressure (in. wg)
UNIT VOLTAGE
208/230-3-60
014
460-3-60
575-3-60
208/230-3-60
016
460-3-60
575-3-60
All All
All All
1 / 1 1 1 /
2 2
† 1132 1105
1436 1410 1384
† 1010 989
kW
3750 4000 4500
14,34 0.05 0.05 0.06
42,56 0.06 0.06 0.07
15,32 0.05 0.05 0.06
55 0.06 0.06 0.07
37 0.06 0.06 0.07
26,34
* * *
42,56
32
* * *
55
50 * * *
— 0.03 0.03 0.04
— 0.16 0.18 0.22
NOTES:
1. Heaters are rated at 208 v, 240 v, 480 v, and 600 v.
2. The factory assembled horizontal adapter substantially improves
fan performance. See Fig. 29.
3. The static pressure must be added to external static pressure.
The sum and the indoor-air section entering-air cfm should then
be used in conjunction with the Fan Performance table to deter-
mine blower rpm, bhp, and watts.
MOTOR PULLEY TURNS OPEN
2 2 1 / 3 3 1
2
1078 1051 1024 997
1358 1332 1305 1279
968 947 926 905
CONTINUOUS AIR CIRCULATION — Turn unit power
on. Set system control at OFF position. Set fan switch at ON
position. The indoor-fan contactor is energized through the
thermostat switch and the indoor fan runs continuously.
CYCLE-LOC™ PROTECTION — If unit operation is inter-
rupted by an open high-pressure switch, low-pressure switch,
indoor coil freezestat, or by compressor internal line-break
device (overcurrent or overtemperature), and compressor is
calling for either cooling or heating. Cycle-LOC protection
device simultaneously locks out unit and lights a warning light
on the thermostat. Restart the unit by manually turning thermo-
stat to OFF and then to ON position. If any of the protective de-
vices opens again, the unit continues to lock out until corrective
action is taken.
NOTE: If the unit fails to operate due to compressor overcur-
rent condition, restart by manually resetting circuit breakers
at the unit. Restart cannot be accomplished as the room
thermostat.
EMERGENCY HEAT — If compressor is inoperative due
to a tripped safety device (high or low pressure, indoor coil
freezestat, overcurrent, or overtemperature), the Cycle-LOC
device locks out the compressor and lights a warning light on
the room thermostat. When the switch is on (thermostat is set
to the EM HT position), compressor circuit and outdoor ther-
mostats are bypassed), and the second stage of thermostat
energizes the indoor blower and the electric resistance heaters.
20
CFM
5000 5600 6000 6250
0.07 0.08 0.09 0.09
0.08 0.10 0.12 0.13
0.07 0.08 0.09 0.09
0.08 0.10 0.12 0.13
0.08 0.10 0.12 0.13
0.08 0.09 0.09
*
0.10 0.12 0.13
0.08 0.09 0.09
*
0.10 0.12 0.13
* 0.13 0.15 0.16
0.05 0.06 0.07 0.07
0.26 0.31 0.35 0.37
/ 4 4 1 / 5
2 2
970 943 916
1253 1227 1201
883 862 841
7200 7500
† †
† †
† †
0.11 0.12
0.16 0.17
0.11 0.12
0.15 0.17
0.20 0.21
0.09 0.10
0.44 0.46
5 1 / 6
2
889 862
— —
820 799