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c l i m a t e m a s t e r. c o m
T H E S M A R T S O L U T I O N F O R E N E R G Y E F F I C I E N C Y
P a c k a g e d U n i t s
R e v. : 1 / 0 6 / 0 9 B
ECM Blower Control
The ECM fan is controlled by an interface board that converts
thermostat inputs and
fi
eld selectable CFM settings to signals
used by the ECM motor controller. Units manufactured before
July 2005 have version I (P/N 69243707). Units manufactured
after July 2005 have version II (P/N 17B0019N01). Fan speeds
are selected with jumpers for version I or via a nine position
DIP switch for version II. To take full advantage of the ECM
motor features, a multi-stage thermostat should be used
(2-stage heat/2-stage cool or 3-stage heat/2-stage cool).
Note:
Power must be off to the unit for at least three seconds
before the ECM motor will recognize a speed change.
The motor will recognize a change in the CFM Adjust or
dehumidi
fi
cation mode settings while the unit is powered.
There are four different air
fl
ow settings from lowest air
fl
ow
rate (speed tap 1) to the highest air
fl
ow rate (speed tap 4). The
charts below indicate settings for both versions of the ECM
interface board, followed by detailed information for each
setting.
Cooling Settings
: The cooling setting determines the cooling
(normal) CFM for all units with ECM motor. Cooling (normal)
setting is used when the unit is not in dehumidi
fi
cation mode.
This setting also determines the heating CFM for Genesis
(GS) units. Tap 1 is the lowest CFM setting, while tap 4 is the
highest CFM setting. To avoid air coil freeze-up, tap 1 may
not be used if the dehumidi
fi
cation mode is selected. Consult
submittal data or speci
fi
cations catalog for the speci
fi
c unit
series and model to correlate speed tap setting to air
fl
ow in
CFM.
Heating Settings
: The heating setting determines the
heating CFM for Tranquility 27™ (TT) and Tranquility 20™
(TS) units. This setting is not used for Genesis (GS) units. Tap
1 is the lowest CFM setting, while tap 4 is the highest CFM
setting. Consult submittal data or speci
fi
cations catalog for
the speci
fi
c unit series and model to correlate speed tap
setting to air
fl
ow in CFM.
Auxiliary/Emergency Heat Settings
: The auxiliary/
emergency heat setting determines the CFM when the unit is
in auxiliary heat or emergency heat mode. This setting is used
for residential units with internal electric heat. When auxiliary
electric heat is energized (i.e. compressor and electric heat),
the greater of the auxiliary/emergency or heating setting
will be used. A “G” (fan) signal must be present from the
thermostat for electric heat to operate. Consult the submittal
data or speci
fi
cations catalog for the speci
fi
c unit series and
model to correlate speed tap setting to air
fl
ow in CFM.
CFM Adjust Settings
: The CFM adjust setting allows four
selections. The NORM setting is the factory default position.
The + or – settings adjust the air
fl
ow by +/- 15%. The +/-
settings are used to “
fi
ne tune” air
fl
ow adjustments. The TEST
setting runs the ECM motor at 70% torque, which causes the
motor to operate like a standard PSC motor, and disables the
CFM counter.
Dehumidi
fi
cation Mode Settings
: The dehumidi
fi
cation
mode setting provides
fi
eld selection of humidity control.
When operating in the normal mode, the cooling air
fl
ow
settings are determined by the cooling tap setting above.
When dehumidi
fi
cation is enabled there is a reduction in
air
fl
ow in cooling to increase the moisture removal of the heat
pump. Consult submittal data or speci
fi
cations catalog for the
speci
fi
c unit series and model to correlate speed tap to air
fl
ow
in CFM. The dehumidi
fi
cation mode can be enabled in two
ways.
1. Constant Dehumidi
fi
cation Mode: When the
dehumidi
fi
cation mode is selected (via DIP switch or
jumper setting), the ECM motor will operate with a
multiplier applied to the cooling CFM settings (approx.
20-25% lower air
fl
ow). Any time the unit is running in
the cooling mode, it will operate at the lower air
fl
ow
to improve latent capacity. The “DEHUM” LED will be
illuminated at all times. Heating air
fl
ow is not affected.
NOTE: Do not select dehumidi
fi
cation mode if cooling
setting is tap 1.
2. Automatic (Humidistat-controlled) Dehumidi
fi
cation Mode:
When the dehumidi
fi
cation mode is selected (via DIP
switch or jumper setting) AND a humidistat is connected
to terminal DH (version II) or HUM (version I), the cooling
air
fl
ow will only be reduced when the humidistat senses
that additional dehumidi
fi
cation is required. The DH (or
HUM) terminal is reverse logic. Therefore, a humidistat
(not dehumidistat) is required. The “DEHUM” LED will
be illuminated only when the humidistat is calling for
dehumidi
fi
cation mode. Heating air
fl
ow is not affected.
NOTE: Do not select dehumidi
fi
cation mode if cooling
setting is tap 1.
Summary of Contents for Genesis Compact (GC) Series
Page 2: ......
