33
START-UP
Use the procedure outlined below to initiate proper unit
start-up.
NOTE: This equipment is designed for indoor installation only.
Operating Limits
ENVIRONMENT — This equipment is designed for indoor
installation ONLY. Extreme variations in temperature, humidi-
ty and corrosive water or air will adversely affect the unit per-
formance, reliability and service life.
POWER SUPPLY — A voltage variation of ± 10% of name-
plate utilization voltage is acceptable.
UNIT STARTING CONDITIONS — Units start and operate
in an ambient temperature of 45 F with entering-air tempera-
ture at 50 F, entering-water temperature at 60 F and with both
air and water at the flow rates used.
NOTE:
These operating limits are not normal or continuous
operating conditions. Assume that such a start-up is for the
purpose of bringing the building space up to occupancy tem-
perature. See Table 18 for operating limits.
1. Restore power to system.
2. Turn thermostat fan position to ON. Blower should start.
3. Balance airflow at registers.
4. Adjust all valves to the full open position and turn on the
line power to all heat pump units.
5. Operate unit in the cooling cycle first, then the heating
cycle. Refer to Table 18 for unit operating limits. Al-
low 15 minutes between cooling and heating tests for
pressure to equalize.
NOTE: Two factors determine the operating limits of a unit:
entering-air temperature and water temperature. Whenever any
of these factors are at a minimum or maximum level, the other
two factors must be at a normal level to ensure proper unit
operation. See Table 18.
Table 18 — Operating Limits —
50PTH, PTV, PTD Units
LEGEND
NOTE: Value in heating column is dry bulb only. Any wet bulb reading is
acceptable.
Fig. 33 — HWR Schematic
a50-8145
W
a
ter O
u
t
(To W
a
ter Loop)
W
a
ter In
(From W
a
ter Loop)
Mixing V
a
lve
COAX
Ev
a
por
a
tor Coil
Rehe
a
t
Coil
Refriger
a
nt O
u
t
(Cooling)
Refriger
a
nt In
(Cooling)
Entering Air
Le
a
ving
Air
Intern
a
l P
u
mp
NOTE: All components shown are
internal to the heat pump unit.
WARNING
When the disconnect switch is closed, high voltage is pres-
ent in some areas of the electrical panel. Exercise caution
when working with the energized equipment.
AIR LIMITS
COOLING (F)
HEATING (F)
Min. Ambient Air
45
40
Rated Ambient Air
80
70
Max. Ambient Air
100
85
Min. Entering Air
50
40
Rated Entering Air db/wb
80/67
70
Max. Entering Air db/wb
110/83
80
WATER LIMITS
Min. Entering Water
30
20
Normal Entering Water
50-110
30-70
Max. Entering Water
120
90
db
—
Dry Bulb
wb —
Wet Bulb
