Important Installer Note; Phase Monitor; Rated Cfm; Service Hints - Bard Q-TEC Series Literature Assembly

Intelligent Reset
The compressor logic control board has an intelligent
reset feature after a safety control is activated. The
controller locks out the unit for 5 minutes; at the end
of this period, the controller checks to verify that all
faults have been cleared. If faults have been cleared,
the controller restarts the unit. If a second fault
occurs, the controller will lockout the unit until the
control is reset by breaking Y signal from thermostat.
The last fault will be kept in memory after a full
lockout; this is only cleared by cycling the unit power.
Alarm Output
The L terminal has 24 volts applied when a hard
lockout occurs. This can be used to drive a fault light
or a low voltage relay.
During routine operation of the unit with no power
interruptions, the compressor will operate on demand
with no delay.
High Pressure Switch and Lockout Sequence
If the high pressure switch opens, the compressor
contactor will de-energize immediately. The lockout
timer will go into a soft lockout and stay in soft lockout
until the high pressure switch closes and the delay on
break time has expired. If the high pressure switch
opens again in the same operating cycle, the unit will
go into manual lockout condition and the alarm relay
circuit will energize. Recycling the wall thermostat
resets the manual lockout.
NOTE Both high and low pressure switch controls are
inherently automatic reset devices. The high
pressure switch and low pressure switch cut
out and cut in settings are fixed by specific
heat pump unit model. The lockout feature,
both soft and manual, are a function of the
compressor logic control board.
MODEL
QW2S3
QW3S3
QW4S3
QW5S3
NOTE:
These units are equipped with a variable speed (ECM) indoor motor that automatically adjusts itself to
maintain approximately the same rate of indoor airflow in both heating and cooling, dry and wet coil
conditions, and at both 230/208 or 460 volts.
Maximum ESP (inches WC) shown is with 2" MERV 8 pleated filter.

 Rated CFM for ducted applications – required for maximum performance rating.
l Continuous CFM the total airflow being circulated during continuous blower operation.
Manual 2100-738A
Page 30 of 71
TABLE 4
Indoor Blower Performance
RATED MAX. ESP
ESP

0.10 0.5
0.15 0.5
0.20 0.5
0.20 0.5

IMPORTANT INSTALLER NOTE

For improved start up performance, wash the indoor
coil with dishwashing detergent.

PHASE MONITOR

All units with three phase scroll compressors are
equipped with a three phase line monitor to prevent
compressor damage due to phase reversal.
The phase monitor in this unit is equipped with two
LEDs. If the Y signal is present at the phase monitor
and phases are correct, the green LED will light and
contactor will energize. If phases are reversed, the
red fault LED will be lit and compressor operation is
inhibited.
If a fault condition occurs, reverse two of the supply
leads to the unit. Do not reverse any of the unit factory
wires as damage may occur.

RATED CFM

All models covered by this manual are factory set to
operate at rated CFM levels as shown in Table 4. Rated
CFM is required for ducted applications for maximum
performance ratings.

SERVICE HINTS

1. Caution user to maintain clean air filters at all
times and to not needlessly close off supply air
registers. This may reduce airflow through the
system which shortens equipment service life as
well as increasing operating costs and noise levels.
2. Check all power fuses or circuit breakers to be sure
that they are the correct rating.
3. The heat pump wall thermostats perform multiple
functions. Be sure that all function switches are
correctly set for the desired operating mode before
trying to diagnose any reported service problems.
CONTINUOUS RATED
AIRFLOW 1st STAGE
l 
800 800
800 900
900 1200
900 1400
RATED
2nd STAGE

950
1150
1450
1650