Dometic 3109228.001 Troubleshooting Manual
TROUBLESHOOTING
Manual Compliments of
Northwest RV Supply
Printed From
http://www.nwrvsupply.com
for the
5 BUTTON 3109228.001
COMFORT CONTROL
CENTER SYSTEM
AIR CONDITIONER
BULLETIN A29/2A
JANUARY 2002
INTRODUCTION
The Comfort Control Center control system can be used to
operate the following Duo-Therm Units:
Roof Top Air Conditioners
Roof Top Heat Pumps
Basement Air Conditioners
Basement Heat Pumps
Dual Basement Air Conditioners
Dual Basement Heat Pumps
Other Manufacturer’s Furnaces
A majority of air conditioner and heat pump problems are
electrical and can be found very easily.
To find a problem in the electrical system, you need to be
able to diagnose the following:
1. Power Source 10. PTCR Device
2. Cable Assembly 11. Heat Strip
3. Compressor 12. Cold Control
4. Capacitors 13. Ambient Sensor
5. Motors 14. Configuration
6. Remote Sensor 15. Comfort Control Center
7. Wiring 16. System Reset
8. AC Power Module 17. DC Voltage
9. Reversing Valve
TOOLS REQUIRED
The air conditioner can be checked with a voltmeter, ohmmeter, clamp-on ammeters and two good thermometers.
Some clamp-on ammeters can read voltage and ohms.
FIG. 1
Form No. 3307835.003 1/02
(French 3307836.001)
©2002 Dometic Corporation
LaGrange, IN 46761
A. QUICK-CHECK TROUBLE-
SHOOTING FOR COMFORT
CONTROL CENTER (CCC)
CONTROLS
For detailed troubleshooting, refer to section noted.
1. Air Conditioner/Heat Pump turned on –
No display
a. Reset - Sec. B15
b. DC Voltage - Sec. B17
c. Cable Assembly - Sec. B2
d. AC Control Module - Sec. B8
e. Comfort Control Center (CCC) - Sec. B15
2. Air Conditioner/Heat Pump turned on –
Has display, improper operation
a. Power Source - Sec. B1
b. Reset - Sec. B16
c. Configuration - Sec. B14
d. Wiring - Sec. B7
e. AC Control Module - Sec. B8
f. Comfort Control Center (CCC) - Sec. B15
3. Air Conditioner/Heat Pump turned on –
Fan runs, No compressor operation
a. Start Relay/PTCR - Sec. B10
b. Start Capacitor - Sec. B5
c. Fan/Run Capacitor - Sec. B4
d. Cold Control - AC Only, Sec. B12
e. Outdoor Ambient Sensor (HP) - Sec. B13
f. Compressor - Sec. B3
g. Wiring - Sec. B7
h. Comfort Control Center - Sec. B15
i. AC Control Module - Sec. B8
4. Air Conditioner/Heat Pump turned on – Compressor runs, No fan operation
a. Fan/Run Capacitor - Sec. B4
b. Motor - Sec. B5
c. Wiring - Sec. B7
d. Comfort Control Center (CCC) - Sec. B15
e. AC Control Module - Sec. B8
5. Heat Pump turned on – Compressor runs and
fan runs, No heat output
a. Reversing Valve - Sec. B9
b. Wiring - Sec. B7
c. AC Control Module - Sec. B8
1
B. DETAILED TROUBLESHOOTING
Manual Compliments of
Northwest RV Supply
Printed From
http://www.nwrvsupply.com
FOR COMFORT CONTROL
CENTER (CCC) CONTROLS
We will now start electrically troubleshooting Comfort Control Center (CCC) controlled units. The best place to begin
is at the power source.
1. POWER SOURCE
If the compressor or fan fails to operate, it is probably not
receiving power. Be sure the power cord is plugged in and
no fuses or breakers are tripped.
Note: Many customers use extremely long power cords
that are undersized. If possible, ask the owner to hook up
the RV just like it was when the problem occurred.
FIG. 2
Make note of the wire size and length of wire. Compare it to
the chart for wire sizing.
For normal operation of the unit, AC voltage
must stay between 103.5 VAC and 126.5 VAC.
Operation of the unit outside of this voltage
range can result in component damage.
To determine if power is reaching the air conditioner, the
inside plastic air diffuser box must be removed. The junction
box will now be exposed. Remove the cover from the junction box to gain access to the connection between the RV
and the unit wires (FIG. 3). Check with a voltmeter for voltage at the connections of the unit to RV wires. USE CAU-
TION as 115 volts may be present.
If no voltage is present, the problem is in the coach wiring or
breaker/fuse box.
2. CABLE ASSEMBLY
A flat control cable must be routed from the unit to the Comfort Control Center. It must be 26 gauge, stranded copper
wire, four (4) conductor (yellow, green, red, and black). The
cable must be terminated with a four (4) position telephone
RJ-11 Connector.
Note: Do not use a pre-made telephone extension cable.
The order of the connectors is reversed and will cause a
failure of the system.
CURRENT WIRE SIZE
IN
AMPS 16 14 12 10 8 6
LENGTH IN FEET
5 47 76 121 192 216 486
10 38 60 96 153 243
15 25 40 64 102 162
20 30 48 76 121
FIG. 3
FIG. 4
2
The cable should be made in the following manner:
Manual Compliments of
Northwest RV Supply
Printed From
http://www.nwrvsupply.com
Cut the control cable to the desired length. When cutting
make sure ends are cut straight, not diagonally. Next, use
an RJ-11 connector crimping tool.
Use the stripper section of the tool to remove the outer insulation of the cable. Be careful not to remove or break the
colored insulation of the inner conductors. Repeat on opposite end.
Insert the prepared cable into the RJ-11 plug. When inserting cable you MUST be sure that the black wire is on your
left as you look at the top of the plug. See FIG. 5. Insert the
RJ-11 plug into the tool and squeeze to the stop. Repeat
the procedure for other end.
FIG. 5
The finished cable can be tested with a 3107127.007 comfort control cable tester. See Section B16 for more information on the testing of the cable.
3. COMPRESSOR
The compressor motor can be electrically checked. Be
sure to disconnect all power and turn all switches to the
“OFF” position, before starting to do the tests.
Remove the terminal cover from the compressor and disconnect the three leads connected
to the terminals. Make note of the positions
so the wires can be replaced correctly.
Use an ohmmeter to check for continuity through the overload device. If no continuity is found and the compressor is
hot, allow 15 to 20 minutes for the compressor to cool. If a
repeat of the test shows the overload to be open, it is defective and requires replacement.
Continuity should exist between all three terminals of the
compressor. If there is no continuity the compressor windings are open and the compressor is defective.
Scrape the compressor casing to bare metal and check
continuity from each terminal to the casing. If continuity is
found to the casing on any of the terminals, the compressor
is shorted and it is defective.
4. CAPACITORS
Duo-Therm Air Conditioners and Heat Pumps use three different capacitors: 1) compressor run capacitor 2) compressor start capacitor and 3) fan/blower capacitor. On some
units the compressor run and fan/blower capacitor are in
the same case.
The compressor run and fan/blower capacitor are housed in
a steel or aluminum case. The start capacitor is in a bakealite or plastic shell. Some have a 15,000 ohm bleeder
resistor across the terminals.
The power must be turned “OFF” and capacitors must be
discharged before making the test. Use an AC voltmeter
(set to the highest scale) or a 15,000 ohm 2 watt resistor to
bleed away any charge left in the capacitor.
Remove the wires from the terminals and inspect the casing. If it is bulged, cracked or split, the capacitor is defective.
Use an analog voltmeter (dial or hand reading indicator) to
test the capacitor after it has been discharged. Set the
ohmmeter to mid-range and check for resistance to the case.
Any resistance to the case from the terminals indicates it is
defective and it needs to be replaced.
Set the ohmmeter to the highest scale and read across the
terminals on the capacitor. The ohmmeter should swing
towards zero and slowly move back towards infinity. Reverse the leads and repeat the test. If the ohmmeter stays
on infinity, it is open and needs to be replaced. If very little
meter movement is noticed, switch the meter to a lower
scale and repeat test.
The capacitors with the 15,000 ohm resistor should be
checked on the 1,000 ohm scale. The ohmmeter should
swing below 15,000 ohms and return. Reverse leads and
repeat test. If the capacitor does not act as described it is
defective and needs to be replaced.
5. MOTORS
To determine if a motor is good, test the windings with an
ohmmeter. Disconnect the power supply, and turn all the
switches to the “OFF” position. Disconnect the motor leads
(on some models disconnect the 6 pin plug from the electrical box). The motor should show continuity between all
leads and the white wire. Infinity or no continuity indicates
the winding is open and the motor is defective.
Check for continuity between the motor frame and each lead.
If a continuity reading is present to any lead, the motor is
shorted and defective.
The motor can be tested with an ammeter to determine if
the operation is within the rating (±10%) listed on the model
plate. Many times the motor windings will check good, but
bad bearings or capacitor may be found in an ampere test.
6. REMOTE SENSOR
The remote sensor is the temperature sensor that allows
the unit for a zone to cycle “ON” and “OFF” by temperature.
A remote sensor is used for each unit or zone. A remote
sensor is usually optional for zone 1; but, in some applications the Comfort Control Center is located for convenience
of access and the remote sensor placed for temperature
control.
3
Loading...