26
5.0 SYSTEM START-UP & REFRIGERANT CHARGING
Start-Up
Airflow
5.1 System Start-Up
Overview
Once the system hardware and wiring has been
properly installed, the next step is to start the
system up, verify indoor air-flow, and adjust the
refrigerant charge. To assure optimum comfort,
efficiency, and reliability, it is extremely important
to follow the procedures in this section to assure
the indoor air-flow and refrigerant charge are
correct.
WARNING:
Single-pole contactors
are used on all standard single-phase units
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5.2 Initial System
Power-Up
After all installation steps have been completed,
apply electrical power to the indoor and outdoor
unit only until the indoor air-flow is verified (See
Section 5.3).
After the indoor air-flow has been verified and the
preliminary refrigerant charge has been weighed
in (see section 5.4.2), electrical power may be
applied to the outdoor unit. If the unit is equipped
with a crankcase heater, it is recommended to wait
at least 12 hours after electrical power is applied
to the outdoor unit before starting the compressor
to assure any liquid refrigerant inside the
compressor has been driven out by the crankcase
heater.
5.3 Verifying Indoor
Air-Flow
The air distribution system has the greatest effect
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by the contractor. For this reason, the contractor
should use only industry-recognized procedures.
Duct design and construction should be carefully
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Air supply diffusers must be selected and located
carefully. They must be sized and positioned to
deliver treated air along the perimeter of the space.
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become noisy. If they are not located properly,
drafts can result. Return air grilles must be properly
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small, they also cause noise.
The installers should balance the air distribution
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rooms in the home. This ensures a comfortable
living space.
The correct air quantity is critical to air conditioning
systems. Proper operation, efficiency, compressor
life, and humidity control depend on the correct
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icing. Serious harm can be done to the compressor
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flooding.
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CFM [151 l/s] and 450 CFM [212 l/s]. See the
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being installed.
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before the refrigerant charging process can begin.
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unit combination being installed. Then refer to the
air-handler or gas furnace installation manual to de-
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the necessary adjustments to achieve as close to
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heat pumps. The air-handler or gas furnace must
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mode. Set the thermostat several degrees above
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point to assure the system is operating in the 2nd
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being delivered. Refer to the installation instructions
for the air-handler or furnace for further details on
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on the indoor unit control board.