Table of Contents
Advertisement
Service Procedures
7 .3 .10 Anti-Ice Routine
The Q3 control occasionally shuts down the compressor
when in Cool Mode to allow any ice to melt that may
have formed on the evaporator coil. The anti-ice
routine shutdown occurs when the conditioned space
temperature falls below 70 °F (21 °C). The default setting
of 70 °F (21 °C) can be adjusted. See "21: Anti-Icing
Routine Adjustment" on page 18.
During a ten-minute cycle period, the compressor shuts
off for 15 seconds for each degree below 70 °F (21 °C)
(default). For example, if the inside temperature is 67 °F
(19 °C), the compressor will shut off for 45 seconds, and
then run for nine minutes and 15 seconds, repeating this
cycle in ten-minute intervals.
8 Service Procedures
WARNING: EXPLOSION AND/OR HEALTH
HAZARD .
This unit contains refrigerant gas under pressure.
Avoid puncturing or breaking any tubing. Failure to
obey this warning could result in death or serious
injury.
WARNING: ELECTRICAL SHOCK HAZARD .
Failure to obey these warnings could result in
death or serious injury:
• Disconnect all power before working within any
electrical enclosure or before handling any electrical
connections.
• Before operating the unit, be certain the unit is
properly grounded.
NOTICE: Do not use any other refrigerant in this system.
Do not put liquid into the discharge line if the unit is
running. Do not remove R-410A as a vapor. Unit damage
can occur.
This section has information to help you service the unit
components and replace the unit, if needed. Remember
to check the basics before replacing any parts, such as
loose wiring, overall installation, or operational issues.
Refer to "Power/Installation Issues" on page 28,
"Operation Checks" on page 29, or "Maintenance"
on page 44 for more details.
32
For any wiring actions in this section, refer to "Q3
Control and ASCDU15HV 1161 Wiring Diagram" on
page 12.
8 .1
Checking the System Pressure
I
Connecting the gauges should always be a last
resort. Every time the gauges are connected,
contaminants can be introduced into the system.
Alway check the air flow, the return air, and the
temperature differential first.
Use this procedure to check the system pressure when
the gauges are attached to the unit.
1. Connect the proper line on the gauge manifold to
the discharge line. The discharge pressure will be
measured on the port beside the pressure switch.
2. Connect the proper line on the gauge manifold
to the suction line. The suction pressure will
be measured on the suction line entering the
compressor.
3. Run the unit and check the pressures. The discharge
pressure is usually two and a half to three times
higher than the suction pressure.
If the compressor, condenser fan, and evaporator fan
are running with proper air flow and the pressures
are abnormally high or erratic, the system may be
contaminated with non-condensables. Evacuate and
recharge by weight with clean R410A.
I
Static pressure in the system only indicates
there is pressure in the unit. It does not indicate
there is enough refrigerant in the system. It can
indicate there is a leak or a low charge in the
system.
8 .2 Checking the System For Leaks
I
If both the suction and discharge pressures seem
low, add nitrogen or R-410A to pressurize the unit.
With a pressurized system, check all of the joints for
leaks by applying a soap and water mixture. If leaks are
present, the soap will bubble at the location of the leak.
Air Conditioner
EN
Advertisement
Table of Contents
