43
1.
Check the line-to-line voltage on the fuse
block connected to the supply fan motor
and ensure it is between 187VAC to
264VAC
2.
Turn the potentiometer to 50%
3.
Energize the BC relay by making a
blower call.
4.
Check DC voltage on S1 (-) and S2 (+),
0-10VDC signal on S1 & S2 sets the
speed of the motor – thus 0VDC is no
speed and 10VDC is full speed.
5.
If DC Voltage is present on S1 & S2 then
ensure that BC (blower relay) is
energized and is passing the DC voltage
through to the motor. If BC is not
energized then check wiring for 24VAC
blower call.
6.
If no DC voltage is present on S1 & S2
then check S1 (-) & S3 (+), this is the
+10VDC output from the motor that is
supplied to the Potentiometer for speed
control.
If the following troubleshooting suggestions
do not solve the issue, contact AAON for
assistance.
Adjusting Refrigerant Charge
Adjusting the charge of a system in the field
must be based on determination of liquid sub-
cooling and evaporator superheat. On a
system with a TXV liquid sub-cooling is
more representative of the charge than
evaporator superheat but both measurements
must be taken.
Before Charging
Unit being charged must be at or near full
load conditions before adjusting the charge.
Units equipped with hot gas reheat must be
charged with the hot gas reheat valves closed
while the unit is in cooling mode to get the
proper charge. After charging, unit must be
operated in reheat (dehumidification) mode
to check for correct operation.
Units equipped with heat pump options must
be charged in heating mode to get the proper
charge. After charging, unit must be operated
in cooling mode to check for correct charge.
Charge may need to be adjusted for cooling
mode. If adjustments are made in the cooling
mode, heating mode must be rerun to verify
proper operation.
After adding or removing charge, the system
must be allowed to stabilize, typically 10-15
minutes, before making any other
adjustments.
The type of unit and options determine the
ranges for liquid sub-cooling and evaporator
superheat. Refer to Table 7 and Table 8
below when determining the proper sub-
cooling.
Checking Liquid Sub-Cooling
Measure the temperature of the liquid line as
it leaves the condenser coil.
Read the gauge pressure at the liquid line
close to the point where the temperature was
taken. You must use liquid line pressure as it
will vary from discharge pressure due to
condenser coil pressure drop.
Convert the pressure obtained to a saturated
temperature using the appropriate refrigerant
temperature-pressure chart.
The Clean Air Act of 1990 bans the
intentional venting of refrigerant
(CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery,
recycling or reclaiming must be
followed. Fines and/or incarceration
may be levied for non-compliance.
CAUTION
Summary of Contents for RQ NextGen Series
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Page 26: ...26 Figure 3 RQ Cabinet Standard and Power Exhaust Gasket Locations...
Page 40: ...40 Figure 23 Post Corner Hole Piping Figure 24 Post Back Hole Piping...
Page 88: ...88 Gas Heater Operating Instructions Figure 36 Gas Heater Instructions...
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Page 105: ...105 Maintenance Log E Coated Coil...
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