NorAire NC-FE series, Инструкция по установке и эксплуатации

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05/16/2014 28 NI216
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The NorAire IDU has a refrigerant receiver thus almost regardless of the line set length, there should be
adequate charge stored within the ODU.
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Also see Mechanical Installation – Outdoor Unit (ODU) section.
External buffer tank boiler, mode C – if this is in the configuration, the backup tabs (COM and NO) provide
contact closure to this external boiler. Verify accordingly.
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This is typically a gas boiler for either standby or backup. If this is an Electro-Boiler that is connected
with an R to W, COM to NO contact, it will function below SW OVER, backup switch, utility interrupt,
hard holds, alarm, etc. If utility interrupt is not involved this is okay.
Power on sequence – if all of the pre-checks and verification have been made, the power on should simply be
the basic running, everyday sequence. However, before leaving the new installation the installer contractor
should run the system at least 15 to 30 minutes and as a minimum verify these points:
1. Front panel indicator lights.
2. Specification sheet GPM flow.
3. Expected output water temperature (both or either heating or chilled water mode) comparing to
specification and nameplate temperature differential.
4. Compressor current, refrigerant pressures, sub-cool, and superheat shown on the unit operating
conditions chart in the Troubleshooting section.
5. Various hydronic floor zones properly flow with the various zone thermostats and the forced air coil
associated with the forced air thermostat.
a. If there is a heating water buffer tank, the temperature build-up or conditions associated with the
various zones coming out of the buffer tank are not critical for this start-up.
b. If a forced air water coil is piped directly to the chilled water out, the system must be run in
cooling long enough to stabilize the water temperature and air temperature outlet to make sure
the water coil is large enough for the specific NorAire model capacity
and there is adequate
airflow within the air handler/forced air ducting system.
Start Up, Cold Slab – this is typically defined as unoccupied building or slab, colder outdoor temperatures, etc.
But remember water freezes at 32° F (0° C). Also, heat pumps or refrigeration cycle equipment cannot handle
cold return at the evaporator. For this product this is defined as 42° F (4° C). NorAire will shutdown with an
alarm if the return water is < 42° F.
These suggestions relate to operating above the SW OVER set temperature (STATUS light is full on, not
pulsing). The balance between efficiency and the length of time required to bring a cold slab up to target
temperature should be considered. The user/contractor may desire to use the high efficient heat pump or use the
electric boiler without a concern for energy cost. There are three possible operating conditions:
A. Allow the system to operate as designed – depending upon operating mode, the previous sequence chart
will take over with the various setup MU’s. Partial electric boiler usage could result.
B. Heat pump only – switch to mode A (power-up reset required), this will prevent electric boiler from
coming on.
C. Electric boiler only – use front panel backup switch. The default stage OT disable values could inhibit
certain portions of the electric boiler from coming on, see PC setup download in the Field Setup section.