Main Power Wiring - Thermal Zone MSC424HP13230A Installation And Maintenance Manual

Step 8
Refrigerant Line Set Piping
Interconnecting line set between the Outdoor unit and the Indoor unit must have both refrigerant lines insulated as condensing
device is located in the Outdoor unit. Gently bend the line set stubs from the Indoor unit to the desired location. Using 2 x 10 -12"
Crescent wrenches remove the flare nuts from the Indoor unit line stubs. Unit is filled with a dry gas, check for release of this to
ensure that no leaks are present. Use a small amount of vacuum pump oil on the male flare threads to ease installation.
Connect the line set to the stubs. Using the 2 wrenches, 1 on the male & 1 on the female, tighten the flare nuts.
DO NOT INSTALL A LIQUID LINE SIGHT GLASS OR FILTER DRIER IN THE SYSTEM
Run the line set to the Outdoor unit. Avoid tight bends and kinking the lines. It is not recommended to braze line sets together or
to the unit connections. If line set length is in excess of that required, cut line set and re-flare or coil excess vertically to facilitate
oil return to the compressor.
Step 9
Evacuation
Gauges can now be attached to the service ports - SERVICE PORTS HAVE a 5/16" CONNECTION TO GAUGES. Use caution
to ensure that the proper size fittings are used when connecting. Once the gauges are attached the line set can be leak checked
using Nitrogen at 300 Psig. Evacuate the unit down to a minimum of 200 Microns, break vacuum with Nitrogen to further leak
check. Re-evacuate the system down to 200 Microns or lower. This is an R410A system; therefore it is essential that a deep
vacuum be pulled on the system to remove all traces of moisture.
Step 10

MAIN POWER WIRING

DANGER
ELECTRICAL WIRING SHOULD BE DONE IN ACCORDANCE WITH NATIONAL AND LOCAL
CODES
Electrical wiring should be done in accordance with all National Electrical Code (NEC) and local state/city building codes
Tip: Small Electrical Screwdriver is required for unit terminals
Breaker size and wiring must be sized for the rating plate amperage. If a smaller than required breaker is used possibility of unit
damage etc could occur. Use only 15 Amp HACR type breakers.
Each system installed must have a separate branch circuit with an individual breaker/fuse. A local disconnect should be
installed adjacent to the Outdoor unit in accordance with National and Local Codes. The Outdoor unit provides power for the
Indoor unit therefore, no disconnect is required between the Outdoor and Indoor units. Line voltage from the disconnect, should
be wired to N - L - G (115V Unit) or L1 - L2 - G (208/230V Unit). Remove RHS Knockout on the terminal access panel for
whip/wiring connection. Ground connection must be made to the terminal plate
Tip: For easier access to the Terminals in the Outdoor unit remove the lower access panel to install whip and sealtite
connectors for conduit.
Step 11
Controls Wiring
ALL CONTROL WIRING BETWEEN INDOOR AND OUTDOOR UNIT IS HIGH VOLTAGE MINIMUM 14 AWG WIRE MUST
BE USED
Remove terminal covers from Indoor unit and wire to the terminals. A small electrical screwdriver required. Control wiring from
the Outdoor Unit must be a point to point i.e. the terminal that the wire is attached to on the Outdoor unit must be the same
terminal it is wired to in on the Indoor unit. DO NOT CROSS WIRES BETWEEN TERMINALS.
This is extremely important
: Mis-wiring (cross connecting wires) between the indoor unit and outdoor unit will cause the
unit to fail to operate at a minimum, and can seriously damage the unit in the worst case. Use extreme care to ensure that wiring
between the inside unit and the outside unit is per the wiring diagrams on the next pages. Ground connection should be made
to ground screw marked in Indoor unit.
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If unit is a Heat Pump Defrost Sensor must be connected from the Indoor unit to the Outdoor unit. Standard lead length is 25ft.
If a longer length is required then cut the lead and extend using thermostat wire.
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