Lennox HS29-012, Unit Information

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FIGURE 4
SCROLL COMPRESSOR
DISCHARGE
SUCTION
The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent properties.
Two identical scrolls are mated together forming concentric spi-
ral shapes. One scroll remains stationary, while the other is al-
lowed to "orbit." The orbiting scroll does not rotate or turn but
merely orbits the stationary scroll. Due to its efficiency, the
scroll compressor is capable of drawing a much deeper vacu-
um than reciprocating compressors. Deep vacuum opera-
tion can cause internal fusite arcing resulting in dam-
aged internal parts and will result in compressor failure.
Never use a scroll compressor for evacuating or for deep
vacuum operation (operating compressor at 0 psig or
lower) on the system.
Three-Phase Compressor Rotation
Three-phase scroll compressors must be phased sequen-
tially to ensure correct compressor rotation and operation.
At compressor start-up, a rise in discharge and drop in suc-
tion pressures indicates proper compressor phasing and
operation. If discharge and suction pressures do not per-
form normally, follow the steps below to correctly phase the
unit.
1 − Disconnect power to the unit.
2 − Reverse any two field power leads to the unit.
(Prefer L1 and L3).
3 − Reapply power to the unit.
Discharge and suction pressures should operate within
their normal start-up ranges.
NOTE − Compressor noise level may be significantly higher
when phasing is incorrect and the unit will not provide cool-
ing when compressor is operating backwards. Continued
backward operation will cause the compressor to cycle on
internal protector.
1 − Crankcase Heater
A crankcase heater is used on all HS29−460 through
HS29−650 models and an option on all others. Some
heaters will be insertion−type and self−regulating while
others will be the band type. The heater is temperature-
actuated and operates only when required.
2 − Compressor Cover (Figure 5)
A compressor cover constructed of vinyl−faced fiberglass is
an option on all HS29 units. The cover provides an acoustic
barrier. The cover slides over the compressor and is held
secure with snap buttons. Slits are provided for installation
around the discharge and suction lines.
SNAP
BUTTONS
SLIT FOR DISCHARGE LINE
SLIT FOR
SUCTION
LINE
COVER
COMPRESSOR
COMPRESSOR COVER
FIGURE 5
C − Condenser Fan Motor
Make sure all power is disconnected before
beginning electrical service procedures.
DANGER
All units use single−phase PSC fan motors which require
a run capacitor. In all units, the condenser fan is con-
trolled by the compressor contactor.
ELECTRICAL DATA tables in this manual show specifi-
cations for condenser fans used in HS29s.
Access to the condenser fan motor on all units is gained
by removing the seven screws securing the fan assem-
bly. See figure 6. The condenser fan motor is removed
from the fan guard by removing the four nuts found on the
top panel. See figure 7 if condenser fan motor replac-
ment is necessary.