Start−Up - Lennox HS29-072 Installation Instructions Manual

9 −Reconnect the manifold gauge to the vacuum pump,
turn the pump on, and continue to evacuate the line
set, indoor unit, and outdoor unit. Continue to evacuate
the line set until the absolute pressure does not rise
above .5 mm of (500 microns) mercury within a 20 min
ute period after you have turned off the vacuum pump
and closed the manifold gauge valves.
10 −When the absolute pressure requirement above has
been met, disconnect the manifold hose from the vac
uum pump. Connect it to an upright cylinder of
HCFC 22 refrigerant.
11 − Open the manifold gauge valves to break the vacuum
in the line set and indoor unit.
12 −Close manifold gauge valves and shut off the
HCFC 22 cylinder and remove the manifold gauge set.
Start−Up
Cooling Start−Up
IMPORTANT
Crankcase heater should be energized 24 hours be
fore unit start−up to prevent damage to the compres
sor as a result of slugging.
1 − Verify that the indoor blower is operating.
2 − Rotate the fan to check for frozen bearings or binding.
3 − Inspect all factory and field−installed wiring for loose
connections.
4 − Check the voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit
nameplate. If it is not, do not start the equipment until
you have consulted the power company and the volt
age condition has been corrected.
5 − To start the unit, set the thermostat for a cooling de
mand, turn on the power to the blower, and close the
condensing unit disconnect switch.
6 − Recheck the unit voltage while the unit is running. The
power must be within the range shown on the unit
nameplate. Check the amperage draw of the unit, and
refer to the unit nameplate for correct running amps.
Three−Phase Compressor Rotation
Three phase scroll compressors must be phased sequen
tially to ensure that the compressor rotates and operates
correctly. When the compressor starts, a rise in discharge
and drop in suction pressures indicate proper compressor
phasing and operation. If discharge and suction pressures
do not perform normally, follow the steps below to correctly
phase in the unit.
1 − Disconnect the power to the unit.
2 − Reverse any two field power leads to the unit.
3 − Reconnect the power to the unit.
The discharge and suction pressures should operate at
their normal start up ranges.
NOTE − Compressor noise level will be significantly higher
when phasing is incorrect. The unit will not provide cooling
when compressor is operating backwards. Continued
backward operation will cause the compressor to cycle on
internal protector.
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