Nordic R-45, Инструкция по установке и обслуживанию

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1-Nov-2021 Page 13 001200MAN-09
Thermostat Requirements
A three-stage heating and two stage cooling heat pump
configurable thermostat is required for two-stage models. The
stages are S1 = Stage 1 compressor, S2 = Stage 2 compressor
and S3 = electric auxiliary (heating only). One can be pur-
chased with the unit, or other heat pump thermostats with the
same number of stages can be used. The electrical box dia-
gram on the electrical box cover provides a description of the
signal connections, as does the below table. Refer to diagram
on a following page for connections between the thermostat and
the heat pump.
NOTE: Some models are not available in two-stage. Model
numbers with a T in the Compressor Stages designator are two-
stage; models with an S are single stage (verify the model num-
ber against pages 2 and 3 of this manual, or refer to the Electri-
cal Specifications near the end of this manual to determine
if the model is two stage or one stage). The Y2 signal is not
used for these units, and they only require a 2 stage heat 1
stage cool thermostat. The stages are S1 = Compressor and
S2 = electric auxiliary (heating only). If the selected thermostat
has more stages than this, configure it for 2 and 1.
TABLE 7 - Control Signal Description
Signal Description
C 24VAC Common (Ground)
G Fan low speed (for air recirculation)
Y
1
Heat Pump Stage 1
R
H
24VAC Hot
L Fault (24VAC when fault condition)
W
2
Heat Pump Stage 3 (auxiliary heat) /
Emergency Heat
O Cooling Mode (reversing valve)
Y
2
Heat Pump Stage 2 (not used for single
stage units)
AR
1
Airflow Reduction*
AR
2
Airflow Reduction*
C
P
(I)
Plenum Heater dry contact
(Connect to C or I in plenum heater)
1
Plenum Heater dry contact.
(Connect to 1 and 2 in plenum heater)
* Connect AR
1
to AR
2
with a dry contact to reduce the air-
flow by 15%. Refer to the Fan Motor sub-section for more
information.
Airflow Reduction for Zoning
For zoning purposes, airflow may be reduced by 15%
using a switch or dry contact connected to AR1-AR2 on the
terminal strip. The dry contact may be from a relay and inter-
connected thermostats, or more commonly a zone controller.
For more zoning advice, see Ductwork chapter.
Airflow Adjustment
The unit is equipped with a direct drive ECM fan motor for
maximum efficiency. The motor features a soft start which pro-
vides a smooth, quiet ramp up to operating speed . The motor
will maintain the programmed air flow up to a maximum external
static value.
The air flow can be set to four different levels by changing
the position on the Air Flow board located in the electrical box.
The four levels are indicated in the table. Refer also to the air-
flow tables in the Model Specific Information section. Units are
shipped with the MED position selected for nominal air flow.
It is recommended that airflow reduction (below) only be
used with the HIGH or MAX air flow setting. Care should be
taken to ensure that the unit does not trip a safety control in
heating or cooling mode if the 15% reduction is used in conjunc-
tion with the MED or LOW air flow setting.
TABLE 8 - Airflow Selections
Position Airflow
LOW -6%
MED Nominal
HIGH +6%
MAX +12%