Heat Controller RG-51G User manual

Heat Controller, Inc. • 1900 Wellworth Ave. • Jackson, MI 49203 • [phone] • www.heatcontroller.com
SERVICE MANUAL
Room Air Conditioner
with R-410A:
RG-51G
Beforeusingyourairconditioner,pleaseread
thismanualcarefullyandkeepitforfuturereference.
WINDOW/WALL TYPE
ROOM AIRCONDITIONER
-

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1.PRECAUTIONS..........................................................................................................2
1.1 Safety precautions.............................................................................................2
1.2 Warning .............................................................................................................2
1.3 Caution ..............................................................................................................2
2. FEATURES AND PANEL...........................................................................................2
2.1 Features.............................................................................................................2
2.2 Control panel illustration ....................................................................................3
POWER .........................................................................................................................4
COOL MODE.................................................................................................................4
FAN MODE .................................................................................................................... 4
THERMOSTAT...............................................................................................................4
3. UNIT DIMENSIONS...................................................................................................5
3.1 Unit dimensions..................................................................................................5
4. OPERATION LIMITS .................................................................................................6
4.1 Cooling operation ...............................................................................................6
5. PROTECTION FUNCTIONS ..................................................................................... 6
6. COMPONENT OPERATION & TESTING..................................................................7
7. WIRING DIAGRAM..................................................................................................12
8. TROUBLESHOOTING............................................................................................. 13
8.1 Flow Chart.........................................................................................................13
8.2 General Troubleshooting...................................................................................16
Table of Contents

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1.PRECAUTIONS
1.1 Safety precautions
• To prevent injury to the user or property damage, the following instructions must be followed.
• Incorrect operation due to ignoring instruction will cause harm or damage.
• Beforeservicingunit,besuretoreadthisservicemanualrst.
1.2 Warning
• Do not use damaged power cords, plugs, or a loose socket.
• Always use the power plug and socket with a ground terminal.
• Do not modify or extend the power cord.
• Do not turn the air-conditioner ON or OFF by plugging or unplugging the power plug.
• Use a dedicated power outlet for this appliance.
• Grasp the plug to remove the cord from the outlet. Do not touch it with wet hands.
• Do not place a heater or any other appliance near the power cable.
• Do not allow water to run into electrical parts.
• Donotstoreoruseammablegasorcombustiblesneartheairconditioner.
• Unplug the unit if strange sounds, odors, or smoke comes from it.
1.3 Caution
• Use a soft cloth to clean the unit. Do not use harsh detergents, solvents, etc.
• Donottouchthemetalpartsoftheproductwhenremovingtheairlter.Theyareverysharp.
• Do not step on or put anything on the air conditioner.
• Do not insert hands or other objects through the air inlet or outlet while the air conditioner is plugged in.
2. FEATURES AND PANEL
2.1 Features
• Powerful cooling.
• Slide-in and slide-out chassis for the simple installation and service (on some models).
• Washableone-touchlterandeasyremovablefrontpanel.
• Super compact design.
• Reliableandefcientrotarycompressor.
• Fresh air ventilation door (on some models).
• Three minute time delay safety for compressor.
• Silverionlter(optional).

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2.2 Control panel illustration
RG-51G Series
Note: The controls featured above are
representative of many available models. Your
model may offer slightly different features.

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POWER:
• Rotate the knob to any position except the OFF position to start the unit. To turn off the unit, rotate the knob
to the OFF position.
COOL MODE:
• The desired cool setting is selected by rotating the knob to the right to the appropriate location.
• MAX COOLhasmaximumcoolingeffectandairow.
• MIN COOLhasminimumcoolingeffectandairow.
FAN MODE:
Rotate the knob to the left to select your choice of fan speeds for air circulation.
Note: When selecting a fan speed, the compressor will not run.
THERMOSTAT
The thermostat is used to set the desired room temperature when the unit is being operated in the COOL MODE.
To set the desired room temperature, rotate the thermostat switch to the desired setting. After the set temperature
is achieved, the thermostat will automatically start and stop the compressor in order to maintain the desired set
temperature.
Rotate the thermostat selector counter clockwise for higher cool settings. Higher cool settings will provide lower
room temperature. Rotate the thermostat selector clockwise for lower cool settings. Lower cool settings will provide
higher room temperature.

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3. UNIT DIMENSIONS
3.1 Unit dimensions
SERIES A (inch/mm) B (inch/mm) C (inch/mm)
RG-51G 16 1/4” / 412 12 5/16” / 312 13 3/4” / 350

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4. OPERATION LIMITS
4.1 Cooling operation
Outdoor unit air temp DB
5. PROTECTION FUNCTION
• Compressor restart time delay
The compressor has an automatic 3 minute time delayed start if the unit is turned off and on quickly, to
prevent pressure imbalance of cooling system from resulting in a locked motor on the compressor.
Indoor air temp DB
Note: The chart is the result from the continuous operation under constant air
temperature conditions. However, excludes the initial pull-down stage.

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6. COMPONENT OPERATION & TESTING
WARNING:
DISCONNECT THE POWER CORD FROM THE POWER PLUG BEFORE SERVICING OR TESTING.
COMPRESSORS
Compressors are single phase, 115 volt, depending on the model unit. All compressor motors are permanent split
capacitor type using only a running capacitor across the start and run terminal.
All compressors are internally spring mounted and externally mounted
on rubber isolators.
COMPRESSOR WINDING TEST (See Figure 1)
Remove compressor terminal box cover and disconnect
wires from terminals. Using an ohmmeter, check
continuity across the following:
1. Terminal “C” and “S” - no continuity
- open winding - replace compressor.
2. Terminal “C” and “R” - no continuity
- open winding - replace compressor.
3. Terminal “R” and “S” - no continuity
- open winding - replace compressor.
GROUND TEST
Use an ohmmeter set on its highest scale. Touch
one lead to the compressor body (clean point of
contact as a good connection is a must) and the
other probe in turn to each compressor terminal
(see Figure 2.) If a reading is obtained, the
compressor is grounded and must be replaced.
CHECKING COMPRESSOR EFFICIENCY
Thereasonforcompressorinefciencyisnormallyduetobrokenor
damaged suction and/or discharge valves, reducing the ability of the
compressor to pump refrigerant gas.
This condition can be checked as follows:
1. Install a piercing valve on the suction and discharge or liquid lines.
2. Attach gauges to the high and low sides of the system.
3. Start the system and run a “cooling performance test.”
If test shows:
A. Below normal high side pressure.
B. Above normal low side pressure.
Figure 2: Typical ground test
Figure 1: Compressor winding test

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C. Low temperature difference across coil.
The compressor valves are faulty - replace the compressor.
THERMAL OVERLOAD (External)
Some compressors are equipped with an external overload which
is located in the compressor terminal box adjacent to the
compressor body (see Figure 3.) The overload is wired in series
with the common motor terminal. The overload senses both
amperage and compressor temperature. High motor temperature
or amperage heats the disc causing it to open and break the
circuit to the common motor terminal.
Heat generated within the compressor shell is usually due to:
1. High amperage.
2. Low refrigerant charge.
3. Frequent recycling.
4. Dirty condenser.
TERMINAL OVERLOAD – TEST (Compressor - External Type)
1. Remove overload.
2. Allow time for overload to reset before attempting to test.
3. Apply ohmmeter probes to terminals on overload wires. There should be continuity through the overload.
TERMINAL OVERLOAD (Internal)
Some model compressors are equipped with an internal overload. The overload is embedded in the motor windings
to sense the winding temperature and/or current draw. The overload is connected in series with the common motor
terminal.
Should the internal temperature and/or current draw become excessive, the contacts in the overload will open,
turning off the compressor. The overload will automatically reset, but may require several hours before the heat is
dissipated.
CHECKING THE INTERNAL OVERLOAD (see Figure 4.)
1. With no power to unit, remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not
continuous, the compressor overload is open and the compressor must be
replaced.
FAN MOTOR
A single phase permanent split capacitor motor is used to drive the evaporator
blower and condenser fan. A self-resetting overload is located inside the motor to
protect against high temperature and high amperage conditions.
FAN MOTOR - TEST
Figure 4: Internal overload
Figure 3: External overload

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1. Determine that capacitor is serviceable.
2. Disconnect fan motor wires from fan speed switch or system switch.
3. Apply “live” test cord probes on red wire and common terminal of capacitor. Motor should run at high speed.
4. Apply “live” test cord probes on white wire and common terminal of capacitor. Motor should run at low speed.
5. Apply “live” test cord probes on each of the remaining wires from the speed switch or system switch to test
intermediate speeds.
CAPACITOR, RUN
A run capacitor is wired across the auxiliary and main winding of a single phase
permanent split capacitor motor such as the compressor and fan motor. A single
capacitor can be used for each motor or a dual rated capacitor can be used for both.
The capacitor’s primary function is to reduce the line current while greatly improving
the torque characteristics of a motor. The capacitor also reduces the line current to
the motor by improving the power factor of the load. The hook-up line side of the
capacitor is marked with a red dot and is wired to the line side of the circuit (see
Figure 5.)
CAPACITOR - TEST
1. Remove capacitor from unit.
2. Check for visual damage such as bulges, cracks, or leaks.
3. For dual rated, apply an ohmmeter lead to common (C) terminal and the other probe to the compressor
(HERM)terminal.Asatisfactorycapacitorwillcauseadeectiononthepointer,thengraduallymovebackto
innity.
4.Reversetheleadsoftheprobeandmomentarilytouchthecapacitorterminals.Thedeectionofthepointer
shouldbetwotimesthatoftherstcheckifthecapacitorisgood.
5. Repeat steps 3 and 4 to check fan motor capacitor.
NOTE: A shorted capacitor will indicate a low resistance and the pointer will move to the “0” end of the
scale and remain there as long as the probes are connected. An open capacitor will show no
movement of the pointer when placed across the terminals of the capacitor.
THERMOSTAT ADJUSTMENT
No attempt should be made to adjust thermostat. Due to the sensitivity of the internal mechanism and the
sophisticated equipment required to check the calibration, it is suggested that the thermostat be replaced rather
than calibrated. Thermostat bulb must be straight to insure proper performance.
Figure 5: Run capacitor

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SEALED REFRIGERATION SYSTEM REPAIRS
EQUIPMENT REQUIRED:
1. Voltmeter
2. Ammeter
3. Ohmmeter
4. E.P.A. Approved Refrigerant Recovery System.
5. Vacuum Pump (capable of 200 microns or less vacuum.)
6. Acetylene Welder
7. Electronic Halogen Leak Detector (G.E. Type H-6 or equivalent.)
8. Accurate refrigerant charge measuring device such as:
a. Balance Scales - 1/2 oz. accuracy
b. Charging Board - 1/2 oz. accuracy
9. High Pressure Gauge - (0 - 400 lbs.)
10. Low Pressure Gauge - (30 - 150 lbs.)
11. Vacuum Gauge - (0 - 1000 microns)
EQUIPMENT MUST BE CAPABLE OF:
1. Recovery CFC’s as low as 5%.
2. Evacuation from both the high side and low side of the system simultaneously.
3. Introducing refrigerant charge into high side of the system.
4. Accurately weighing the refrigerant charge actually introduced into the system.
5.Facilitiesforowingnitrogenthroughrefrigerationtubingduringallbrazingprocesses.
HERMETIC COMPONENT REPLACEMENT

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The following procedure applies when replacing components in the sealed refrigeration circuit or repairing
refrigerant leaks. (Compressor, condenser, evaporator, capillary tube, refrigerant leaks, etc.)
1. Recover the refrigerant from the system at the line located on the high side of the system by installing a line
tap on the line. Apply gauge from line to EPA approved gauges from line to EPA approved recovery system.
Recover CFCs in system to at least 5%.
2. Cut the line below pinch off on the suction side of the compressor.
3. Connect the line from the nitrogen tank to the suction line.
4.Adddrynitrogenthroughthesystemandunsolderthemoredistantconnectionrst.(Filterdrier,highside
line, etc.)
5.Replaceinoperativecomponent,andalwaysinstallanewlterdrier.Adddrynitrogenthroughthesystem
when making these connections.
6. Pressurize system to 30 PSIG with proper refrigerant and boost refrigerant pressure to 150 PSIG with dry
nitrogen.
7. Leak test complete system with electric halogen leak detector, correcting any leaks found.
8. Reduce the system to zero gauge pressure.
9. Connect vacuum pump to high side and low side of system with deep vacuum hoses, or copper tubing. (Do
not use regular hoses.)
10. Evacuate system to maximum absolute holding pressure of 200 microns or less.
NOTE: This process can be speed up by use of heat lamps, or by breaking the vacuum with refrigerant or dry
nitrogen at 5,000 microns. Pressurize system to 5 PSIG and leave in the system a minimum of 10 minutes.
Recover refrigerant, and proceed with evacuation to pressure of 200 microns or a minimum of 10%.
11.Breakvacuumbychargingsystemfromthehighsidewiththecorrectamountofrefrigerantspecied.This
will prevent boiling the oil out of the crankcase.
NOTE: If the entire charge will not enter the high side, allow the remainder to enter the low side in small increments
while operating the unit.
12. Restart unit several times after allowing pressures to stabilize. Pinch off lines, cut and solder the ends.
Remove pinch off tool, and leak check the lines.
COMPRESSOR MOTOR BURNOUT
1. Recover all refrigerant and oil from the system.
2.Removecompressor,capillarytubeandlterdrierfromthesystem.
3. Flush evaporator condenser and all connecting tubing with dry nitrogen or equivalent, to remove all
contamination from system. Inspect suction and discharge line for carbon deposits. Remove and clean if
necessary.
4. Reassemble the system, including new drier, strainer and capillary tube.
5. Proceed with process as outlined under hermetic component replacement.
ROTARY COMPRESSOR TROUBLESHOOTING AND SERVICE
Basically, troubleshooting and servicing rotary compressors is the same as reciprocating compressor with only a
few exceptions:
1. Because of the spinning motion of the rotary compressor, the mounts are critical. If vibration is present,
check the mounts carefully.
2. The electrical terminals on the rotary compressor are in a different order than the reciprocating compressors.
The terminal markings are on the cover gasket. Use the wiring diagram to insure correct connections.

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REFRIGERANT CHARGE
1. Refrigerant charge is extremely critical. Measure charging amount carefully -- as exact as possible to the
nameplate amount.
2. The correct method for charging the rotary compressor is to introduce liquid refrigerant into the high side of
the system with the unit off. Then start compressor and enter the balance of the charge, gas only, into the
low side.
The introduction of liquid into the low side, without the use of a capillary tube, will cause damage to the discharge
valve of the rotary compressor.
7. WIRING DIAGRAM
Wiring Diagram For Mechanical RG-51G:

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8. TROUBLESHOOTING
Ingeneral,possibletroubleisclassiedbythreetypesoffailures.OneiscalledStartingFailurewhichiscaused
from an electrical defect, another is ineffective Air Conditioning caused by a defect in the refrigeration circuit and
improper application, and the other is called the Structure Damage.
8.1 Flow Chart
59°F (15°C).
62°F (17°C).

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The fan motor doesn’t work.
Check whether the indoor (outdoor) fan is locked.
Check the power supply.
No
Check the wiring.
No
Check whether the relays on PCB for motor work normally.
Comparing with fan motor specification, check
the resistance of fan motor.
No
Replace the fan motor.
Cooling mode doesn’t work or cooling not enough
Check the set temperature
Start the unit in the cool mode and check whether the temperature
of compressor’s discharge line is between 176°F (80°F) to 194°F
(90°C). If not, recharge refrigerant.
Replace the capillary tube.
Check whether lter is dirty or clogged.

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Water drips from the unit.
Check whether the ambient humidity is too high.
Check whether the indoor outlet airflow foam is too wet, and louver drip.
Check whether the unit is correctly installed.
Check whether the air outlet foam install normally.
Check whether the foam of evaporator base is damaged.
Check whether the drain passage of evaporator is blocked. Replace if failed.
Fan motor speed can’t change.
Check whether the selector is damaged.
Check whether the capacitor of fan motor is in the range from 95% to
105% of rated capacity. Replace the capacitor if failed.
Check the resistance of fan motor and replace if failed.
Check if the indoor airow foam is too wet and if water is dripping from the louver.
Check whether the air outlet foam is install normally.
Fan motor speed will not change
Check whether the selector knob is damaged.

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8.2 General Troubleshooting
PROBLEM POSSIBLE CAUSE REMARK
Fan motor doesn’t run.
No power Check voltage at electrical outlet. Correct if none.
Power supply cord Check voltage at the power cord terminal. Replace the
power cord if none.
Wire disconnected or
connection loose
Reconnect wire. Refer to wiring diagram for terminal
identication.Repairorreplacelooseterminal.
Main switch failure Check and replace the main switch if failure.
Capacitor (Discharge
capacitor before testing)
Test capacitor.
Replace if not within +/-10% of manufacturer’s rating.
Replace if shorted, open or damaged.
Will not rotate
Fan blade hitting shroud or blower hitting scroll. Realign
assembly. Check fan motor bearings. Replace the motor if
motor shaft does not rotate.
Fan motor runs intermittently Cycles on overload.
Check voltage. Call an electrician if not within limits.
Test capacitor.
Replace if not within +/-10% of manufacturer’s rating.
Check bearings. Replace the motor if the fan blade cannot
rotate freely.
Pay attention to any change from high speed to low
speed. Replace the motor if the speed does not change.
Fan motor noise.
Fan Replace the fan if cracked, out of balance, or partially
missing.
Blower Replace the blower if cracked, out of balance, or partially
missing.
Loose screws Tighten them.
Worn bearings
Replace the motor if knocking sounds continue when
running the motor hums, or noise appears to be internal
while running.
The compressor does not
stop even when the room
temperature has reached the
set temperature.
Thermostat Check and replace if the thermostat is damaged.

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Airow Clean or remove any obstruction that blocks the
inlet/outletairowoftheunit.
Sunlight Protect the condenser from excessive sunlight.
Less refrigerant
Check the lines for leakage. Recycle the
refrigerant, correct the leakage points and
recharge.
Capillary tube
Regulatetheowofthecapillarytubetomakethe
evaporating temperature appropriate if the evapo-
rator is frosted. Replace if blocked. Repair joint if
leaking.
Compressor
The inlet and outlet valve of the compressor is
damaged, making the low pressure connected
with the high pressure. The refrigerating system
can not produce high pressure and low pressure.
Replace the compressor after checking for the
reason.
Heat sources Reduce if too many. Unplug un-used appliances
that are adding heat to the room.
Drainage
Thedrainageisblocked.Itwillincreasetheef-
ciency in cooling mode, but will cause the con-
denser to frost in heating mode.
Stops instantly after startup.
Refrigerant
The amount of the refrigerant is too much, mak-
ing the compressor load too big. Recycle and
recharge the refrigerant after checking for the
reason.
Compressor The compressor is seized. Replace after checking
for the cause of failure.
PROBLEM POSSIBLE CAUSE REMARK
Airlter Clean or replace if restricted.
Vent door Close if open.
Unit undersized Determine if the unit is properly sized for the area
to be cooled or heated.
Condenser and Evaporator Clean or replace if restricted.
Fan motor Check the fan capacitor and replace if not within
+/-10% of manufactures rating.
Room structure
Take proper measures to ensure that the room the
unit is operating in is properly sealed. Close all
open doors or windows.
Insufcientcooling

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PROBLEM POSSIBLE CAUSE REMARK
No cooling
No power Check the voltage. Call an electrician
if no within the limit.
Wiring Check the terminals. Repair and
correct if loose.
Temperature setting Check and adjust the thermostat.
Main switch setting Check and adjust the main switch
setting.
Compressor will not run while
fan motor runs.
Voltage Check voltage. Call an electrician if
not within limits.
Wiring
Check the wire connections, if loose,
repair or replace the terminal. If wires
are off, refer to wiring diagram for
identication,andreplace.Checkwire
locations. If not per wiring diagram,
correct.
Main switch failure Check and replace the main switch if
failure.
Capacitor (Discharge capacitor before
testing)
Check the capacitor.
Replace if not within +/-10% of
manufacturer’s rating. Replace if
shorted, open, or damaged.
Thermostat
Check the thermostat setting if not at
the coolest (in cooling mode) or the
warmest (in heating mode). Set it if
not.
Compressor
Check the compressor for open
circuit or ground. If open or grounded,
replace the compressor.
Excessive noise. Copper tubing
Remove the cabinet and carefully
rearrange tubing not to contact
cabinet, compressor, shroud and
barrier.
The unit starts and stops frequently.
Power supply
The input power supply voltage is too
low. Call an electrician if not within
limits.
Outdoor temperature
When the outdoor temperature is too
high, the compressor will not operate
due to built in safety features.

04/2009
03/2010