Transcript No Slide Title

™
Heat Pump Service
HEAT PUMPS
• TOTAL ELECTRIC UNIT CAPABLE OF
PROVIDING HEATING AND COOLING
• MOVES HEAT WITH REFRIGERATION
SYSTEM.
• CURRENT TECHNOLOGY ALLOWS US
TO ABSORB ENERGY FROM THE
OUTDOOR AIR EFFICIENTLY, DOWN
TO 20º.
• During the winter months the heat pump
absorbs heat from the outdoor air.
• Then releases the heat (energy) into the
indoor air.
• There is energy (heat) present to minus 460º.
• Just as it is more efficient to move an object
than it is to build or make one. It is more
energy efficient to move heat, than generate
it (depending on thermal/economic balance
points).
• Heat pumps are sized for the cooling
demand of the application.
• The heat pump will be the sole source of
cooling for the application. It may be the
only source of heat, depending on heating
requirements.
• Most areas of the country will also require
an additional source of heat. This may be as
little as a 5KW heat strip, or as much as a
80,000 BTU furnace.
• We’ll look at this in more detail later.
HEAT PUMPS
• COOLING SEASON
– HEAT PUMP PERFORMS THE SAME AS
ANY AIR CONDITIONING SYSTEM BY
PICKING UP HEAT FROM THE SPACE
TO BE CONDITIONED AND REJECTING
IT OUTDOORS
HEAT PUMPS
• HEATING SEASON
– UNIT ABSORBS HEAT FROM THE
OUTDOOR AIR AND MOVES IT TO THE
CONDITIONED SPACE
– REVERSE-CYCLE AIR CONDITIONERS
HEAT PUMPS
• CLASSIFIED BY: THE SOURCE OF
HEAT DURING THE HEATING
CYCLE AND THE MEDIUM TO
WHICH THE HEAT IS
TRANSFERRED
– AIR-TO- AIR
– WATER-TO-AIR
INSIDE THE
HEAT PUMP
• COMPRESSOR CAPABLE OF OPERATING AT
LOW OUTDOOR TEMPERATURES
• INDOOR / OUTDOOR COIL DESIGN
• METERING DEVICE FOR INDOOR / OUTDOOR
COIL
• REVERSING VALUE ( 4-WAY VALUE )
• ACCUMULATOR
• CRANKCASE HEATER
• AUXILIARY HEAT
• EMERGENCY HEAT
• DEFROST CYCLE
HEAT PUMP
• ACCUMULATOR
– CLIMATUFF - PART OF COMPRESSOR SHELL
– LOCATED IN SUCTION LINE BETWEEN THE
COMPRESSOR AND REVERSING VALUE
– WHY HAVE ONE?
• MOST IMPORTANT:
– HEATING CYCLE - COLD TEMPERATURES, OUT DOOR
COIL MAY NOT BE ABLE TO EVAPORATE ALL THE
REFRIGERANT
– END OF DEFROST CYCLE
– LIQUID CARRYOVER WILL BE CAUGHT BY THE
ACCUMULATOR TO PREVENT COMPRESSOR DAMAGE
WHAT MAKES A HEAT
PUMP UNIQUE
•
•
•
•
SPECIAL COMPRESSOR
MUCH HIGHER COMPRESSION RATIO
MOST SEVERE APPLICATION
HEAT PUMP COILS
– ALTERNATELY FUNCTION AS EVAPORATOR
AND CONDENSER
– MUST TOLERATE CHARGE IMBALANCE
– OUT DOOR COIL MUST BE DESIGNIED FOR
EASY DEFROST
HEAT PUMP
• CRANKCASE HEATER
– LOCATED ON COMPRESSOR, OLDER
SYSTEMS USED COMPRESSOR
WINDINGS.
– RAISES TEMPERATURE OF OIL SO
THAT THE ABSORPTION OF
REFRIGERANT INTO THE
COMPRESSOR IS KEPT TO A MINIMUM
COOLING CONDITION
INDOOR COIL
SAT. SUCT. T. 41F
ENT. AIR T. 76F
4-WAY
VALUE
METERING
DEVICE
SUBCOOLING
10F
SUCT. P. 70 PSIG
SUCT. T. 52F
SUPERHEAT 11F
DISCHARGE
PRESSURE
260 PSIG
OUTDOOR COIL
SAT. COND. T. 120F
ENT. AIR T.
90F
COMPRESSOR
HEATING
CONDITIONS
INDOOR COIL
SAT. COND. T. 95F
ENT. AIR T. 70F
4-WAY
VALUE
METERING
DEVICE
SUBCOOLING
10F
SUCT. P. 43 PSIG
SUCT. T. 35F
SUPERHEAT 10F
DISCHARGE
PRESSURE
182 PSIG
OUTDOOR COIL
SAT. SUCT. T. 20F
ENT. AIR T.
45F
COMPRESSOR
HEAT PUMP
• TOTAL HEAT REJECTED EQUALS
HEAT ABSORBED +
HEAT OF COMPRESSOR
HEAT PUMP
THE REVERSING
VALUE CONTROLS THE
DIRECTION
THE REFRIGERANT FLOWS
COOLING CONDITION
INDOOR COIL
SAT. SUCT. T. 41F
ENT. AIR T. 76F
4-WAY
VALUE
METERING
DEVICE
SUBCOOLING
10F
SUCT. P. 70 PSIG
SUCT. T. 52F
SUPERHEAT 11F
DISCHARGE
PRESSURE
260 PSIG
OUTDOOR COIL
SAT. COND. T. 120F
ENT. AIR T.
90F
COMPRESSOR
HEATING
CONDITIONS
INDOOR COIL
SAT. COND. T. 95F
ENT. AIR T. 70F
4-WAY
VALUE
METERING
DEVICE
SUBCOOLING
10F
SUCT. P. 43 PSIG
SUCT. T. 35F
SUPERHEAT 10F
DISCHARGE
PRESSURE
182 PSIG
OUTDOOR COIL
SAT. SUCT. T. 20F
ENT. AIR T.
45F
COMPRESSOR
Heat pump Thermostats
• Thermostats with adjustable heat
anticipation need to have it adjusted for
proper operation!
COOL
F
O
HA
TS
C1
COOL
H1
X2
FAN
AUTO
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
HEAT PUMP
THERMOSTAT
Y
RHS-1
BAYSTAT239 OR 240
CA
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Energized In Cooling
F
COOL
Fault Indication Light
SOV Energized In Cooling
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Brings On Compressor In Both
Heating And Cooling
F
COOL
Fault Indication Light
SOV Energized In Cooling
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Energized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Energized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
Part of Heat Anticipation Circuit (Used
with Trane Electro-Mechanical T’stats
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Engerized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
Part of Heat Anticipation Circuit (Used
with Trane Electro-Mechanical T’stats
This Is The Second Stage-Brings
On The Electric Heat
Functions As An Internal Connection
For The Blue Light
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Engerized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
Part of Heat Anticipation Circuit (Used
with Trane Electro-Mechanical T’stats
This Is The Second Stage-Brings
On The Electric Heat
Functions As An Internal Connection
For The Blue Light
This Is The Common Side Of The
Transformer
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Engerized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
Part of Heat Anticipation Circuit (Used
with Trane Electro-Mechanical T’stats
This Is The Second Stage-Brings
On The Electric Heat
Functions As An Internal Connection
For The Blue Light
This Is The Common Side Of The
Transformer
This Is The Other Side Of 24 Volts
From The Transformer
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
Fault Indication Light
SOV Engerized In Cooling
Brings On Compressor In Both
Heating And Cooling
Energizes Auxiliary Heat When
Unit Is In Defrost
Brings On Indoor Fan
Part of Heat Anticipation Circuit (Used
with Trane Electro-Mechanical T’stats
This Is The Second Stage-Brings
On The Electric Heat
COOL
F
O
HA
TS
C1
COOL
H1
X2
FAN
AUTO
ON
SM-2
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
ODA
HEAT PUMP
THERMOSTAT
Y
RHS-1
BAYSTAT239 OR 240
CA
COOL
F
O
HA
CA
Y
RHS-1
TS
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
ODA
NORM
T
TSH
INDOOR UNIT
G
W
BL
B
U
W1
RD
R
B
R
RHS-2
G
COOL
F
O
HA
CA
Y
TS
RHS-1
C1
H1
COOL
X2
AUTO
FAN
G
ON
SM-2
ODA
NORM
T
TSH
INDOOR UNIT
G
W
BL
B
U
W1
RD
R
B
R
RHS-2
FAN ON - ON
BAYSTAT240A
COOLING ON
COOL
F
O
HA
CA
Y
RHS-1
TS
C1
COOL
H1
X2
AUTO
FAN
G
ON
SM-2
ODA
NORM
T
TSH
W
BL
U
INDOOR UNIT
RD
G
B
B
W1
R
R
COOLING ON FAN - AUTO
RHS-2
FAN - AUTO
OUTDOOR UNIT
BAYSTAT240A
Defrost Board
COOL
F
O
HA
CA
R
Y
TS
RHS-1
C1
H1
COOL
Y
R/W
X2
X2
O
AUTO
BL
FAN
ON
NORM
ODA
Y
SM-2
O
T
TSH
W
BL
U
INDOOR UNIT
RD
G
B
B
W1
R
R
COOLING ON FAN - AUTO
RHS-2
G
BL
COOL
HEATING - ON - FIRST STAGE
F
O
FAN - AUTO
HA
CA
Y
RHS-1
TS
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
15 TO 22 VOLTS (T)
FROM ODS-A TO (R)
ODA
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
G
BAYSTAT240A
COOL
F
O
HA
CA
Y
RHS-1
TS
C1
COOL
H1
X2
AUTO
FAN
ON
SM-2
ODA
NORM
T
TSH
W
BL
INDOOR UNIT
U
RD
G
B
B
W1
R
R
RHS-2
G
OUTDOOR UNIT
BAYSTAT240A
Defrost Board
COOL
F
O
HA
CA
O
Y
TS
C1
H1
COOL
Y
R/W
X2
RHS-1
R
X2
AUTO
BL
ON
NORM
ODA
Y
SM-2
O
T
TSH
W
BL
INDOOR UNIT
U
RD
G
B
B
W1
R
R
RHS-2
G
FAN
BL
F
FAN - AUTO
O
COOL
HEATING - ON - 2ND STAGE
HA
CA
Y
RHS-1
TS
C1
COOL
H1
X2
AUTO
FAN
ON
NORM
ODA
15 TO 22 VOLTS (T)
FROM ODS-A TO (R)
SM-2
T
TSH
W
BL
U
RD
B
R
RHS-2
G
24 VOLT S (O)
FROM DEF. BRD
COOL
F
O
HA
CA
Y
RHS-1
TS
H1
COOL
X2
AUTO
FAN
G
15 TO 22 VOLTS (T)
FROM ODS-A TO (R)
SM-2
ODA
ON
NORM
T
TSH
W
BL
U
RD
B
R
RHS-2
24 VOLT S (X2)
FROM DEF. BRD
C1
(OPERATES 1.5° BELOW
SETPOINT)
BAYSTAT240A
F
COOL
HEATING ON EMERG. HTG
O
HA
CA
Y
TS
RHS-1
C1
COOL
H1
X2
AUTO
FAN
G
ON
SM-2
ODA
NORM
T
TSH
W
BL
INDOOR UNIT
U
RD
G
B
B
W1
R
R
RHS-2
FAN - AUTO
WHAT IS COOLING DROOP?
• Cooling droop is caused by the cooling
anticipator heating up during the off cycle,
causing the t’stat to come on sooner, to help
overcome the thermal lag of the system.
• This also provides night time cooling that
helps keep humidity under control
DROOP (cont’)
• Then there is Heating Droop.
• Heating Droop moves the temperature in
the wrong direction. To compensate for this,
the “T” circuit is added.
WHAT DOES THE “T”
CIRCUIT HAVE TO DO WITH
ANYTHING?
• The “T” circuit is a heat anticipation circuit
that adds heat to the thermostat to slow
down thermostat response, and removes
heat to speed up the response.
“T” Circuit
• As the outdoor temperature drops, the
resistance in the “T”, actually a thermistor
(ODS-A), goes up.
• The higher the resistance, the less voltage is
supplied to the resistor (ODA) located
inside the thermostat.
• The less voltage to the ODA, the colder the
t’stat thinks it is.
R e s is ta
9
6
5
4
1 0
3
3
2
2
9
1
1
1
1
8
1
n c e
5 0 0
4 0 0
4 0 0
04 0 50 0
7 0 0
2 0 0
7 0 0
4 0 0
0 0 0
9 5 0
7 0 0
4 5 0
1 5 0
0 0 0
0 7 0
9 2 0
7 2 0
6 2 0
05 0 40 5
4 8 0
4 2 0
3 7 0
03 0 30 0
2 8 5
2 6 0
2 3 0
2 0 5
0 0 0
1 8 5
1 6 5
1 4 5
1 3 0
01 0 10 5
1 1 0
D
e fr o s t
T h e r m
is t e r
R
e s is t a n c e
DEFROST THERMISTOR RESISTANCE
10000
9000
8000
7
6
6000
5
5000
4
4000
3 0 0 0
3000
2 0 0 0
2000
1 0 0 0
-40
0
O
35
u t d o o r
T e m
p e r a t u r e
OUTDOOR TEMPERATURE
1 1 5
1 0 5
9 5
75
8 5
7 5
6 5
5 5
4 5
3 5
2 0
1 0
0
- 1 0
- 2 0
0
- 3 0
1000
- 4 0
R
e s is t a n c e
7000
115
4000
13.6 V
.047 W
.0034 A
ODS-A
3000
10.4 V
.036 W
-20°F
4000
13.6 V
.047 W
2000
9.6 V
.046 W
.0034 A
3000
10.4 V
.036 W
-20°F
.0048 A
3000
14.4 V
.069 W
0°F
ODS-A
ODS-A
4000
13.6 V
.047 W
2000
9.6 V
.046 W
800
5V
.031 W
.0034 A
3000
10.4 V
.036 W
-20°F
.0048 A
3000
14.4 V
.069 W
0°F
ODS-A
ODS-A
.0063 A
ODS-A
3000
19 V
.119 W
30°F
4000
13.6 V
.047 W
2000
9.6 V
.046 W
800
5V
.031 W
300
2.2 V
.013 W
.0034 A
3000
10.4 V
.036 W
-20°F
.0048 A
3000
14.4 V
.069 W
0°F
ODS-A
ODS-A
.0063 A
ODS-A
.0073 A
ODS-A
3000
19 V
.119 W
30°F
3000
21.8 V
.159 W
70°F
DEFROST BOARD DURING DEFROST
K2
OD
230 VOLTS
R
T’STAT
R
Y
Y
RD/W
F
BR/BL
Motor
K1
BK
X2
O
O
T
B
BL
Y
COMPR
O
SOV
T
SENSORS
T
WHY IS THE BLUE LIGHT
ON?
THE BLUE LIGHT IS AN INDICATION
THAT THE AUXILIARY HEAT IS ON.
• It is on in several instances.
– If the t’stat is adjusted above set point.
– If the outdoor temperature is below 40°F it will
cycle off and on to maintain room temperature.
• If it stays on constantly above 30°F or
cycles on when the outdoor temp. is above
50°F, the system should be checked.
WHY IS THE RED LIGHT ON
STEADY?
The Red Light on steady is an
indication the Emergency Heat
Switch is on.
• The switch is used only if the heat pump is
inoperative, but not due to a power failure.
• Using the heating in this mode will increase
your power consumption.
• The red light is to remind the customer that
the temperature is being controlled by
resistance heat only.
THE RED LIGHT ON, BUT IT
IS FLASHING
The Emergency Heat switch is in the Normal
position.
RED LIGHT FLASHING
• If the red light is flashing, this is an
indication that the defrost board has
detected a defrost fault.
• Reset by moving the Emergency Heat
Switch to the “on” position for 30 seconds.
• If the flashing returns, service on the heat
pump may be required.
HEAT PUMP
REVERSING VALUE
ILLUSTRATION
SUCTION LINE
OUT DOOR COIL
TP-4
INDOOR COIL
. . .
TP-2
TP-3
.
TP-1
COMPRESSOR DISCHARGE
TO
ACCUMULATOR
TO
INDOOR COIL
FROM
OUTSIDE COIL
TP-4
. . .
TP-2
TP-3
FROM COMPRESSOR
DISCHARGE LINE
HEATING MODE
.
TP-1
5F
MAX TEMP.
DIFFERENCE
TO
ACCUMULATOR
TO
OUTDOOR COIL
TP-4
FROM
INDOOR COIL
. . .
.
TP-3
TP-2
TP-1
FROM COMPRESSOR
DISCHARGE LINE
COOLING MODE
5F
MAX TEMP.
DIFFERENCE
HEAT PUMP
• METERING DEVICES
– HEATING CYCLE, REFRIGERANT IS
METERED TO THE OUTDOOR COIL
– COOLING CYCLE, REFRIGERANT IS
METERED TO THE INDOOR COIL
HEAT PUMP
• METERING DEVICES
• REFRIGERANT METERED TO COIL
WHICH ABSORBS HEAT
• HEATING CYCLE REFRIGERANT
METERED TO OUTDOOR COIL
• COOLING CYCLE REFRIGERANT
METERED TO INDOOR COIL
METERING DEVICES
• CAPTUBE
• FIXED ORFICE
• TXV
METERING DEVICES
FLOW BYPASSES METERING DEVICE
CHECK VALUE
OPEN
METERING
DEVICE
FLOW IS METERED
CHECK VALVE
SHUT
METERING
DEVICE
The role of the defrost control
• To extract heat from the outdoor air, the
heat pump must lower it’s outdoor coil
temperature below that of the outdoor
ambient.
• Depending on the humidity and
temperature, frost may form on the outdoor
coil.
• This frost will insulate the coil from the
outdoor air, reducing it’s ability to absorb
the heat from the outdoor air.
•
•
•
•
•
•
•
•
•
-
HEAT PUMP DEFROST
CONTROLS
CONTROLS THE DEFROST CYCLE IN A HEAT PUMP
DURING HEATING OPERATION.
THE DEFROST CONTROL CONTROLS THE
FOLLOWING FUNCTIONS:
1SWITCH OVER VALVE OR REVERSING VALVE
2OUTDOOR FAN MOTOR
3ELECTRIC OR GAS AUX. HEAT
4INDICATES A FAULT HAS OCCURRED
(OPTIONAL)
CONTROL THAT ESTABLISHES THE NEED FOR A
DEFROST
BOTH TIMED AND DEMAND CONTROLS ARE USED
TODAY
ELECTRO MECHANICAL TIMERS AND PRESSURE
SWITCHES USED IN THE PAST
Heat pump defrost controls
• Several types of defrost controls have been
used through the years.
• We will discuss their function and
diagnostics of each type.
• The newer solid state and Demand Defrost
controls will be the main focus of our time
today.
As the frost accumulates on the outdoor coil,
the systems capacity is reduced.
Ö To remove the frost/ice from the outdoor coil,
the system will shift itself into a variation the
cooling mode.
Ö During a defrost cycle the outdoor fan will
stop, leaving the heat in the coil to remove the
frost.
Ö The type of defrost control system will
dictate how much frost/ice is allowed to
accumulate prior to initiating a defrost.
DEFROST CYCLE
• SYSTEM IN COOLING MODE-ENERGIZE REVERSING VALVE
– DIRECTS HOT GAS TO OUTDOOR COIL
TO MELT THE FROST
DEFROST CONTROLS
• THE MUCH OLDER EQUIPMENT
UTILIZED ELECTRO-MECHANICAL
TIME CLOCKS.
• ELECTRONIC TIMER - TIME &
TEMPERATURE DEFROST
• SOLID STATE - DEMAND DEFROST
DEFROST CYCLE
• TEMPERING INDOOR AIR
– ELECTRIC HEAT IS TURNED ON TO
TEMPER THE AIR DURING DEFROST
CYCLE.
DEFROST CYCLE
• OUTDOOR FAN OFF
– ENHANCES DEFROST
Electro-Mechanical systems
ç All electro-mechanical systems are a
“time/temperature” based control.
ç A predetermined amount of time must pass
before a defrost cycle can be initiated.
ç As mentioned earlier, the outdoor
conditions have major impact on the
amount of defrost needed.
ç These systems are temperature activated as
well.
Large amounts of frost may accumulate
before the “Time” has elapsed.
• This results in lower seasonal efficiency.
• The reduced capacity will result with a greater
dependence on a secondary heat source.
ELECTRONIC TIME-TEMPERATURE
DEFROST CONTROL
• 50 - 70 - 90 MINUTE COMPRESSOR RUN TIME
SELECTION
• 10 MINUTE TIME OVERRIDE IN DEFROST
CYCLE
• TWO TEST PINS - ADVANCES ELECTRONIC
TIMER AND PUTS SYSTEM INTO DEFROST
CYCLE FOR TESTING
• ON BOARD DEFROST RELAYS FOR OUTDOOR
FAN, SOV VALVE AND AUXILIARY HEAT
• DEFROST TERMINATED ON TIME OR
TEMPERATURE
• COMPRESSOR RUN TIME IS KEPT ONLY WHEN
COIL THERMOSTAT IS CLOSED
• The defrost thermostat is set to close at 25º.
• When the DT is closed, supplying 24 VAC
to the D terminal, jumpering the test pins
will speed up the internal clock.
• If you are testing the system, and have a
jumper from R to D, remove the jumper as
soon as the system shifts into defrost. To
prevent excessive refrigerant pressures.
• These controls will default to the 90 minute
setting if the selector jumper is not connected.
Which is how the equipment is shipped.
• I recommend one of the shorter time
settings, 50 or 70 minutes.
• The water run off from a unit in defrost is
pure water, and has never been reported to
caused roof damage to date!
• Trying to catch the water could damage the
outdoor coil (if the collected water froze and
backed up under the coil).
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
TST EDR
R
R
B
B
X2
Y
O
O
D
T
There are several versions of these DFC boards.
Many feature the exact same functions, with the
only difference being the terminal for the defrost
thermostat being labeled “D” or “DT”.
TST EDR
R
R
B
B
X2
Y
O
O
D
T
There are several versions of these DFC boards.
Many feature the exact same functions, with the
only difference being the terminal for the defrost
thermostat being labeled “D” or “DT”.
TST EDR
R
R
B
B
X2
Y
O
O
D
T
There are several versions of these DFC boards.
Many feature the exact same functions, with the
only difference being the terminal for the defrost
thermostat being labeled “D” or “DT”.
TST EDR
R
R
B
B
X2
Y
O
O
D
T
There are several versions of these DFC boards.
Many feature the exact same functions, with the
only difference being the terminal for the defrost
thermostat being labeled “D” or “DT”.
TST EDR
R
R
B
B
X2
Y
O
O
D
T
There are several versions of these DFC boards.
Many feature the exact same functions, with the
only difference being the terminal for the defrost
thermostat being labeled “D” or “DT”.
TST EDR
R
R
B
B
X2
Y
O
O
D
T
DFC
K2
CNT1152 1
OR
CNT1642
K1
M1
OD
FAN
M2
90 70 50
TST EDR R
R B B
X2 Y
24V AC
24V COMMON
INDOOR
THERMOSTAT
MS
SC
1
CNT1152 may be replaced
by CNT 1642
DT
O
O
D
T
K2
DFC
CNT1642
K1
M1
OD
FAN
M2
90
70
50
TST
EDR R
R
B
B
X2 Y
O
O
DT
T
X2
INDOOR
THERMOSTAT
Y
O
T
SC
DT
EDR
EDR
24V AC
24V COMMON
ECONOMIZER
(OPTIONAL)
EDC OR LPCO
MS
INDOOR
THERMOSTAT
G
TR TR1
F
COMMON FOR
ELECTRIC
HEATER
TIMER DEFROST CONTROL
DEMAND
DEFROST
CONTROLS
DEMAND DEFROST
• FEATURES
–
–
–
–
–
–
ADAPTABILITY
LEARNING PROCESS
DEFROST ON DEMAND
DIAGNOSTICS
TIME OVERRIDE
SOFT SWITCHOVER
DEMAND DEFROST CONTROLS
HEAT PUMP DEMAND DEFROST
CONTROLS
• TRANE DEMAND DEFROST CONTROLS
OPERATE IN AN ADAPTIVE PROCESS TO
OPTIMIZE THE HEAT PUMP PERFORMANCE.
• THE DEMAND DEFROST CONTROL WILL
ADAPT TO THE HEAT PUMP IT IS INSTALLED
ON AND LEARN ITS OPTIMUM DEFROST
CONDITIONS AND STORE THEM IN MEMORY.
• THE DEMAND DEFROST CONTROL WILL
ADJUST THE TIME BETWEEN DEFROST
CYCLES TO MATCH THE WEATHER
CONDITIONS.
HEAT PUMP DEMAND DEFROST
CONTROLS
• -
THE DEMAND DEFROST CONTROL WAS DEVELOPED
BY TRANE IN 1984 AND IS PATENTED.
• HEAT PUMP SYSTEMS WITH DEMAND DEFROST
CONTROLS BENEFIT FROM A 6% HEATING SEASONAL
PERFORMANCE FACTOR (HSPF) ADVANTAGE.
• THERMISTOR SENSORS SENSE THE OUTDOOR
AMBIENT TEMPERATURE AND OUTDOOR COIL
TEMPERATURE.
• THE DIFFERENCE BETWEEN THE OUTDOOR
TEMPERATURE AND THE OUTDOOR COIL
TEMPERATURE IS CALLED THE DELTA TEMPERATURE
OR JUST DELTA-T.
The Defrost Cycle is Initiated
• As ice builds on the coil, the delta-t of the system increases
until it reaches the initiate value, and the control starts the
defrost process.
• The initiate value is not constant, but instead, is a value that the
defrost control has learned will provide a fast, thorough defrost
at a given outdoor temperature.
• Low initiate values waste energy by defrosting too often, while
high initiate values fail to defrost the coils thoroughly.
• The control is continually varying the initiate value slightly to
learn the best value.
• It measures the success of each initiate value by measuring the
delta-t of the system during the next heating cycle.
DEFROST IS TERMINATED
• Once the temperature of the outdoor coil reaches the
termination value, the defrost control turns on the outdoor fan.
After waiting the soft-switch over time, it changes the switch
over valve to the heating mode.
• This soft-switch over delay time, 12 seconds, gives the
outdoor coil time to cool, reducing the refrigerant pressure
and reducing the surge that occurs when the switch over valve
is switched.
• If the compressor or “Y” cycles off during defrost, the
switchover valve remains energized but the “X2” output will
be OFF. If “Y” cycles off during the soft-switchover time, the
switchover valve is switched OFF immediately.
Demand Defrost Control Operation
•
•
•
•
•
•
•
Requirements for defrost initialization
1 - The outdoor temperature must be less than 52 F
2 -The coil temperature must be less than 33 F
3 -The Y line must be energized for a least 128
seconds
4 -The delta-T must be greater than the initiate
temperature
5 - It must be time for a timed defrost
6 -30 minutes of run time have passed since the unit
was first powered up
Demand Defrost Control
Operation
• If the unit is placed into a forced defrost by
placing the test jumper in the FRC DFT position
and Y is energized, none of the above conditions
need to be met.
• Defrost Controls groups 8 thru 21 have a 6 hour
forced defrost below 6 degrees F outdoor
temperature with a 3 minute timed override.
Requirements for Defrost
Termination
• The coil temperature must exceed the terminate
value.
• If the outdoor temperature is greater than 22 F, the
terminate value is 47 F.
• If the outdoor temperature is less than 10 F, the
terminate value is 35 F.
• If the outdoor temperature is between 10 F to 22 F,
the terminate value is 25 F plus the outdoor
temperature.
OR
• The defrost control has a for 15 minute override
time.
The Test Mode
• The control may be placed into a test
mode by placing the RED jumper wire on
the TST pin.
• This will cause the LED to blink rapidly
and the operation of the control will be
five times faster.
• The controller will run normally once the
jumper is removed from the TST pin.
Fault Indications
• There are three types of faults the demand defrost control
can experience.
• All three faults can cause the defrost control to change from
a demand defrost control to a timed defrost control which
defrosts the unit every 30 minutes.
• When the control goes into a timed defrost mode due to a
FAULT A or FAULT C, on units that have the F line
feature, it alerts the home owner by energizing the F line
once every second which flashes a fault light on the
thermostat.
• If the thermostat is switched to the emergency heat
position, the F line will be energized, and the defrost
control will be cleared of all faults after a few seconds.
Fault Indications
•
•
•
•
•
FAULT A is indicated by 2 led flashes per second.
FAULT A is caused by one of two conditions:
1 - During heating the system's delta-T is unusually low.
(The capacity of the system is lower than it should be.)
2 - After 12 minutes of operation since the defrost
termination, delta-T is greater than the initiate value.
• After running in a FAULT A condition for 30 minutes, the
defrost control will indicate it by flashing the LED. After
running 2 hours with this fault, the demand defrost
control will then change to a timed defrost operation, and
the homeowner will be notified via the F line.
Fault Indications
• FAULT A can be cleared by any one of the
following operations:
• 1 - If the control has two normal defrost cycles
•
(If the fault has been present long enough
for the Fault light to start Flashing, it will flash
until the first normal defrost.)
• 2 - If power is removed from the defrost
control for more than 30 seconds.
• 3 - If the F line is energized for a few seconds.
Fault A
Fault A
Fault A
Fault A
Fault A
Fault A
Fault A
Fault A
Fault A
Fault Indications
• FAULT B is indicated by 3 led flashes per
second.
• FAULT B is caused by 10 successive failures
of the heat pump to terminate on temperature
during the defrost cycle.
• The unit will stop defrosting after 15 minutes
due to the override timer.
• Once a FAULT B occurs, the control will
indicate it by flashing the led. After FAULT B
occurs 10 times, the control will act as a timer
defrost control.
Fault Indications
• FAULT B can be cleared by any one of the
following operations:
• 1 - If the control reaches the terminate value
during one of the timed defrost cycles.
•
(Since this fault is pretty common in cold
climates with high winds, this fault does not alert
the home owner via the F line.)
• 2 - If power is removed from the defrost control
for more than 30 seconds.
• 3 - If the F line is energized for a few seconds.
Fault Indications
• FAULT C is indicated by 3 led flashes per
second.
• FAULT C is caused by 15 successive faults
in which the unit has an unusually high
delta-T 15 minutes after a defrost
termination.
• (Poor air flow over outdoor coils - they are
probably blocked by ice.)
Fault Indications
• FAULT C can be cleared by any one of the
following operations:
• 1 - If the unit has a normal delta-T 15 minutes
after a defrost. (If the fault has been present long
enough for the Fault light to start flashing, it will
continue to flash until there is a defrost cycle
without a high delta-T fault.)
• 2 - If power is removed from the defrost control
for more than 30 seconds
• 3 -If the F line is energized for a few seconds
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Fault B or C
Combination Fault
Indications
• FAULT A & FAULT B, indicated by 4 led flashes per second, is
caused by 60 or more FAULT A's occurring and one or more
FAULT B's occurring.
• FAULT A & FAULT C, indicated by 4 led flashes per second, is
caused by 60 or more FAULT A's occurring and one or more
FAULT C's occurring.
• Combination faults will notify the home owner by toggling the F
line.
• Combination faults can be cleared by any one of the following
operations:
• 1 - If the F line is energized for a few seconds
• 2 - If power is removed from the defrost control for more than 30
seconds
Power-up Initial Defrost
• After the defrost board is powered up, its first
defrost cycle will be a timed cycle.
• On the newer boards, the unit must run during
defrosting conditions for 30 minutes while
some older boards must run for 45 minutes.
• Assuming there are no faults, subsequent
defrost cycles will be performed on demand.
• The delay in each case can be reduced to 1/5
this time by placing the red jumper lead on the
TST terminal.
Forcing the Unit to Defrost
• Placing the red jumper wire on the FRC DFT pin,
the defrost board can be forced to initiate a defrost
immediately even if outside temperature
conditions are not met.
• The only requirement is that the compressor is
running or the “Y” signal is present.
• The defrost will be terminated normally when the
outdoor coil becomes hot enough.
• If the jumper is still on the FRC DFT lead upon
defrost termination, it will initiate the defrost
cycle again.
F Line Operation
• Full featured defrost controls (G15-G17 &
G19-G20) have an F line to alert the home
owner in the event of a fault.
• On older controls, the F line would continue
to flash a fault to the home owner after the
fault was gone, but newer boards stop
flashing the Fault light after the faults A, B,
and C have passed.
• This will hopefully cut down on nuisance
service calls, and still yet alert the home
owner if the heat pump fails.
No Fault Found
• DON’T REPLACE IT!
– If LED blinks,
– & Sensors ohm out OK,
– & Forced defrost works.
• Look Elsewhere For Cause(s)
• Package Unit Ambient Sensor Bracket
– Added for better ambient sensing
ODS-A Thermistor Failures
• Cause
– Field miswire during installation
• Solution
– X2 wire color changed from BR/X2 to BK
• DO NOT REPLACE CONTROL
– Use RES0118 ODS-A kit
– Needed ONLY for GE “blue light” thermostat
Defrost Control Failures
• Early defrost controls would sometimes fail to
defrost with the LED steady ON or OFF.
• If power is removed for 1 minute, the board will
resume normal operation.
• After months of research at Trane and the
microprocessor manufacturer, the mechanisms
for this type of failure were discovered, and the
new defrost boards were designed and tested to
resist this type failure.
• Defrost controls manufactured after Jan. 1995
have this improvement made.
Defrost Control Failures
• The second problem is caused by miswiring.
• Often, the anticipator lead has been confused
with the X2 lead, because the leads were both
brown.
• In current generation outdoor units the “X2”
lead is black, so the incidence of field
miswiring should go down.
Temperature Sensors
• The temperature sensors are temperature dependent
resistors encased in a heat-shrunk plastic shroud and
sealed from air and moisture by a hot glue adhesive
fill.
• The resistance of the sensor decreases as temperature
increases according to a specified curve. See the
temperature / resistance curve provided with the
service information.
• It is rare for a temperature sensor to fail, and most that
have been replaced in warranty were OK, or they had
been damaged by rough handling.
Temperature Sensors
• A common problem with sensors is damage
inflicted by forcing ohmmeter probes into their
connectors. This permanently bends the
contact causing an intermittent connection.
• On some package units, the sensor leads have
been pinched by the access panel. Checking
the sensor resistance to ground will detect this
problem.
Check Out Procedure
• The following tests are to be performed to check for
proper operation after installation of the demand
defrost control.
• Step 1: Apply power to the system and operate in
heating mode. The switchover valve should be off
(heating mode), and the outdoor fan should be on.
• Step 2: Check to be sure the led on the defrost board
is blinking once every second and the fault light on the
thermostat is off.
• Step3: Force the system to defrost by placing the red
jumper wire on the FRC DFT pin.
Check Out Procedure
• As the unit goes through the defrost process, the
switchover valve should be energized, the
auxiliary heat should be on and the outdoor fan
motor should be off.
• Step 4: Monitor the system to be sure it stops
defrost within 15 minutes.
• Step 5: At the end of the defrost cycle, the
outdoor fan should come on, and after a 12
second delay, the unit will switch back to the
heating mode.
Check Out Procedure
• Step 6: If the board has the fault light feature (G15-G17&
G19-G20), test this feature by placing the red jumper wire on
the FRC FLT pin for a few seconds then return the red
jumper wire to the NORM pin.
• This should cause the led on the defrost board to blink four
times a second, and the indoor fault indicator on the
thermostat should be blinking once a second.
• Step 7:
Switch the indoor thermostat to the emergency
heating position for at least 30 seconds and then back to the
heat pumps position.
• The indoor fault indicator should stop blinking and the LED
should blink once a second indicating that everything is
normal.
Helpful Hints in Case of
Difficulty
• Led fails to blink on the defrost board
•
If the led is off, check between R
and B to be sure 24 volts is present.
•
Remove power for one minute and
re-apply power. Check to see if the
LED starts flashing.
•
•
•
•
Helpful Hints in Case of
Difficulty
LED flashes, but the unit fails the forced defrost test.
1. Be sure the red jumper wire was returned to the NORM pin.
2. Make sure the thermostat is calling for heating (24 V on Y)
3. Verify that the sensors are connected and mounted in the right
places
• 4. Check the electrical connections to the defrost board (24V on
O while defrosting)
• 5. There is a 1 minute minimum time in defrost under normal
operation.
•
If defrost is forced there is no minimum time in defrost.
Helpful Hints in Case of
Difficulty
• 1- The indoor fault indicator goes on and then goes off.
• During extreme weather conditions, the unit may have
difficulty defrosting. This will cause a fault and alert the
owner, but when the weather is more temperate, the fault will
clear and the indicator will stop blinking.
• 2 - The outdoor sensor (ODS) is burnt on the defrost board.
• Check control wiring “T” and “X2” .
• On the newer units the X2 lead is black and this is not as
likely to happen.
Demand Defrost Control
Problems
Excessive Ice Built-up on OD Coil
• Low refrigerant charge
• Defrost Control will not Initiate
A. No 24 VAC between R&B at defrost control
B. No 24 VAC between B&Y at defrost control
with system running
C. Verify correct sensor location, mounting &
their resistance
D. Verify ambient sensor is connected to AMB
position on defrost control
E. Verify coil sensor is connected to coil position
on defrost control
Demand Defrost Control
Problems
Excessive Ice Built-up on OD Coil
• SOV Inoperative
A. Stuck in heating mode
B. Open switchover valve (SOV) coil
C. Defective defrost control
• Defrost control contacts to OD fan fail to
open during defrost cycle
Demand Defrost Control
Problems
Excessive Ice Built-up on OD Coil
• Defrost control terminates, but does not
remove ice
A. Windy conditions
B. Outdoor unit located under eaves
C. Lack of proper drainage
D. Night setback operation
Ice Build Up on Lower Part of
Outdoor Coil
• Low refrigerant charge
• Coil sensor connected to wrong pass of
outdoor coil, or poor contact
• Leaking check valve (outdoor unit)
• Distributor tube restricted
• One pass of OD coil restricted
• Lack of proper drainage
Defrost Initiates, but Terminates Only
on a Time Override
•
•
•
•
•
•
•
Low refrigerant charge
Outdoor fan on during defrost
Windy conditions
Night setback operation
Unit location
Coil sensor in contract with ice
Coil sensor circuit open or reading very
high resistance.
Defrost Cycle Initiates, but Will
Not Terminate
• Defrost Control
• Switch-over valve stuck in
cooling mode
Unit Goes Into Defrost In
Cooling Mode
• Defective Sensors
• Defective Defrost Control
Control Terminates Defrost
Before Frost Is Gone
• Coil sensor mounted in wrong
location or has incorrect resistance
reading
• Refrigerant overcharge
Defrost Initiates About Every 15
Minutes
• Coil sensor
• Ambient sensor
• Defrost control
Defrost Initiates About Every 30 Minutes.
Fault Light on Indoor Thermostat Will Be
Flashing If Wired
•
•
•
•
•
•
•
Coil sensor
Ambient sensor
Weather conditions
Night setback operation
Outdoor fan on during defrost
System refrigerant charge
SOV operation
Two-Compressor Controllers
• Tyler Version For V.S. OD Fan Motor
– Cooling model
• 21C150624G02, CNT2275
– Heatpump model
• 21C150625G02, CNT2276
Two-Compressor Controllers
• Ft. Smith Version for PSC Fan Motor
– Cooling model
• 21C150624G01, CNT1858
– Heatpump model
• 21C150625G01, CNT1859
Heat Pump Control
EFFICIENCY
•
•
•
•
EER
COP
SEER
HSPF
EER
BTU’S OUT
POWER IN
39,000 BTU/HR.
4380 WATTS/HR.
=
8.9 BTU/WATT
COP
BTU’S OUT
39,000 BTU/HR
BTU’S WE
4380 WATTS/HR X 3.1413 BTU/WATT
PAY FOR
=
2.6
COP FOR HEAT PUMP AND
RESISTANCE HEAT
4.0
3.0
HEAT PUMP
2.0
RESISTANCE HEAT
1.0
0
-20
-10
0
10 20
30
40
50
OUTDOOR TEMPERATURE
60
HSPF
HEATING SEASONAL PERFORMANCE FACTOR
• TOTAL HEATING OUTPUT OF A HEAT
PUMP DURING ITS NORMAL ANNUAL
USAGE PERIOD FOR HEATING DIVIDED
BY THE TOTAL ELECTRIC POWER INPUT
IN WATT-HOURS DURING THE SAME
PERIOD
SEER
SEASONAL ENERGY EFFICIENCY RATIO
• TOTAL COOLING OF A CENTRAL
UNITARY AIR CONDITIONER OR
UNITARY HEAT PUMP IN BTU’S DURING
ITS NORMAL ANNUAL USAGE PERIOD
FOR COOLING DIVIDED BY, THE TOTAL
ELECTRIC POWER INPUT IN WATTHOURS DURING THE SAME PERIOD
OUTDOOR TEMPERATURE
WHEN CAPACITY DROPS
WHAT CAUSES CAPACITY
TO DROP
GAS
DENSITY
DECREASES
+
SHORTER
EFFECTIVE
STROKE
=
DECREASED
FLOW
RATE
CAPACITY VS. HEAT LOSS
SUPPLEMENTAL
HEAT
NEEDED
TEMPERATURE
ELECTRIC HEAT
•
•
•
•
SUPPLEMENTAL HEAT
EMERGENCY HEAT
AUXILIARY HEAT
RESERVE HEAT
THERMAL BALANCE
POINT
HEAT LOSS
HEATING
CAPACITY
HEAT
PUMP
=
CAPACITY VS. HEAT LOSS
BTU/HR
45,000
21,000
10F
OUTDOOR TEMPERATURE
50F
BALANCE POINT
BTU/HR
BALANCE
POINT
34,500
0
32.5F
OUTDOOR TEMPERATURE
65F
DESIGN POINT
BTU/HR
57,500
NEED
36,500 BTU/HR
ADDITIONAL
21,000
DESIGN
POINT
10F
OUTDOOR TEMPERATURE
EMERGENCY HEAT
BTU/HR
57,500
X 1.00
57,500 BTU/HR
57,500
57,500 BTU/HR
3413 BTU/KW
10F
= 16.8 KW
TOTAL CAPACITY
WITH 17 KW HEATER PACKAGE
BALANCE POINT
1 ST STAGE ELECTRIC HEAT
BALANCE
POINT
22.5F
OUTDOOR TEMPERATURE
BALANCE POINT
2ND STAGE ELECTRIC HEAT
BALANCE
POINT
13F
OUTDOOR TEMPERATURE
BALANCE POINT
3RD STAGE ELECTRIC HEAT
BTU/HR
BALANCE POINT
DESIGN
POINT
4F
10F
OUTDOOR TEMPERATURE
Heat pump with heat strips
• This application has a 17KW heat strip. You
will see that W2 heat strip is brought on
during defrost.
• The W1 and W3 heat strips are controlled
by outdoor thermostats. Only bringing them
on as the outdoor temperature drops.
TDL
SUMP HTR
PURPLE/WH
PURPLE/WH
CS
MS-1
BK/BL
BR/RD
TO LINE VOLTAGE SUPPLY
BLACK
CSR-1
CSR
BR
BK/BL
OR
RD
BLACK
BR/RD
OR
BROWN
CF
PURPLE
LO
RD
FAN
MTR
HI
S
CPR IOL
R
CR
RD
RED
BL/WH
OFT-B
OFT-A
BLACK
BK/RD
CBS
YL
RD
YL
BK
BK
R B B
Y1
O O
Y Y X2 F
ODS-B
RD
YL
YL
BK
T1
R B B
O O
BK
Y Y X2 F
RD/WH
BL
OR
YL
O
BK
OR
WS
X
X
BK
X
X2
X
BK
BK
Y
Y
W3
BK
X
O
HEAT
OFF
HEATER
CONTROLS
W2
CA
RHS-1
TS
X2
X
X
W1
J
G
ODS-A
FAN
CONTROL
BD
COOL
HA
Y
YL
O
SM-1
G
SM-2
AUTO
ON
COOL
BLACK
F
F
HEAT
RD
RHS-2
T
T
BR
T
T
ODA
TSH
W
U
B
BL
B
B
R
R
RD
BL
R
RD
TYPICAL AIR HANDLER
TO POWER SUPPLY PER
LOCAL CODES
TYPICAL MANUAL CHANGE OVER THERMOSTAT
EMERGENCY HEAT
RELAY PACKAGE
MAINTAINS COMFORT IF HEAT PUMP FAILS BY
1
2
3
LOCKING
OUT
COMPRESSOR
BYPASSING
OUTDOOR
THERMOSTAT
BRINGING
ON FULL
STRIP HEAT
SQUEEZING OUT
OPERATIONG $
• DECREASE BALANCE POINT
– OVERSIZE HEAT PUMP
– UPGRADE BUILDING INS. & GLAZING
– TURN DOWN THE THERMOSTAT
• DUAL - ALTERNATIVE HEATING
SYSTEM
• 2 - STAGE HEAT PUMP
LOCATING THE UNIT
• AIR CONSIDERATIONS
– AVOID RECIRCULATION
– CUT OFF PREVAILING WIND
• WATER DRAINAGE
– ALLOW CLEARANCE FOR WATER DRAIN OFF
• SNOW CONSIDERATIONS
– AVOID SNOW DRIFTS
– RAISE UNIT IN HEAVY SNOW AREAS
LOAD CALCULATION
AIR FLOW
CHARGING
CAPACITY
DUAL
FUEL
HEATING “ON”
CYCLE
FOSSIL FUEL
HEAT PUMP
TEMP
TIME
DUAL FUEL SYSTEMS
• DEPENDS ON THE COST OF ELECTRICITY AND
PRICE OF THE FOSSIL FUEL
• LESS EXPENSIVE TO HEAT COMPRESSIONCYCLE EQUIPMENT WHEN THE OUTDOOR
TEMPERATURE IS MILD TO MODERATELY
COLD
• MORE ECONOMICAL TO HEAT WITH FOSSIL
FUEL WHEN THE OUTDOOR TEMPERATURE IS
VERY COLD
• REDUCES DEMAND FOR POWER DURING
PERIODS OF COLD WEATHER
ECONOMIC BALANCE POINT
• OUTDOOR TEMPERATURE ASSOCIATED WITH
EQUAL OPERATING COSTS
ADD-ON HEAT PUMP KIT
TYPLUS103A
• SEQUENCE OF HEATING OPERATION
• NON-RESTRICTIVE MODE
– FIRST STAGE HEAT, HEAT PUMP (ONLY)
OPERATES IN HEATING, IF HEAT PUMP
CANNOT HANDLE THE LOAD , WHEN THE
TEMPERATURE IN ROOM DROPS APPROX. 11/2F, FURTHER, SECOND STAGE HEAT IS
CALLED FOR. SECOND STAGE TURNS THE
HEAT PUMP OFF AND BRINGS THE FURNACE
ON. FURNACE WILL SATISFY SECOND STAGE
ONLY. FIRST STAGE IF CALLING WILL
OPERATE AFTER 45 SEC. DELAY
– THERMOSTAT EMERGENCY HEAT POSITION
OPERATES FURNACE ONLY
ADD-ON HEAT PUMP KIT
TYPLUS103A
• SEQUENCE OF HEATING OPERATION
RESTRICTIVE MODE - ( REQUIRES TAYSTAT250A )
– O.D.T. CHANGEOVER AT OR ABOVE
ECONOMIC BALANCE POINT
– TEMPERATURES ABOVE O.D.T.,HEAT PUMP
ONLY,WHEN CALLED BY FIRST STAGE STAT.
– TEMPERATURES BELOW O.D.T.,FIRST STAGE
STAT. GOES TO THE FURNACE AND HEAT
PUMP IS CUT OFF
– EMERGENCY HEAT POSITION CONVERTS
SYSTEM TO FURNACE ONLY OPERATION
“A” COIL UPFLOW
APPLICATION
AIR FLOW
SUPPLY DUCT
CLASS 2 LOW VOLTAGE
WIRING TO SYSTEM
CONTROLLER
COIL ENCLOSURE
NOTE 1
BONNET THERMOSTAT
“A” COIL
FRONT COIL BAFFLE
UPFLOW
FURNACE
NOTE:
1. MOUNT BONNET THERMOSTAT
THROUGH FRONT COIL BAFFLE AT
THE HIGHEST PRACTICAL POINT
INSIDE THE ‘A’ COIL SO THE
SENSING ELEMENT DOES NOT
TOUCH EITHER SLAB OF COIL OR
INTERFERE WITH TUBING.
ROOM THERMOSTAT
T O R W Y B X2 G
INTER-COMPONENT WIRING
24 V.
FACTORY
LINE V. WIRING
24 V.
W3
FIELD
Y3
X3
LINE V. WIRING
G3
K1-3
FIELD INSTALLED
FACTORY WIRING
K1-2
K1
TDR
G1
HEAT PUMP
O.D. SECTION
BR
T
OR
O
FIELD WIRING
DIAGRAM FOR
SPLIT HEAT
PUMP SYSTEM
WITH
TAYPLUS103A
CONTROL IN
FURNACE
(UNRESTRICTED
MODE)
TDR - 1
Y2
K1-1
BR/X2 OR BK
X2
YL
Y
RD
R
BL
B
FURNACE
X2
BT
TAYPLUS103A Y1
B
G
W1
W1
W2
R
B
LEGEND
TDR - TIME DELAY RELAY
MODEL RLY1664
TO POWER
SUPPLY PER
LOCAL CODES
3 PH. ONLY
K
BT
- RELAY
MODEL RLY1663
- BONNET THERMOSTAT
MODEL THT1248
Y
TO POWER
SUPPLY PER
LOCAL CODES
3 PH. ONLY
ROOM THERMOSTAT
T O R W Y B X2 G
INTER-COMPONENT WIRING
24 V.
FACTORY
LINE V. WIRING
24 V.
W3
FIELD
Y3
X3
LINE V. WIRING
G3
K1-3
FIELD INSTALLED
FACTORY WIRING
K1-2
K1
TDR
G1
HEAT PUMP
O.D. SECTION
BR
T
OR
O
FIELD WIRING
DIAGRAM FOR
SPLIT HEAT
PUMP SYSTEM
WITH
TAYPLUS103A
CONTROL IN
FURNACE
(RESTRICTED
MODE)
TDR - 1
Y2
K1-1
BR/X2 OR BK
ODT
X2
YL
Y
RD
R
BL
B
FURNACE
X2
BT
TAYPLUS103A Y1
B
G
W1
W1
W2
R
B
LEGEND
TDR - TIME DELAY RELAY
MODEL RLY1664
TO POWER
SUPPLY PER
LOCAL CODES
3 PH. ONLY
K
BT
- RELAY
MODEL RLY1663
- BONNET THERMOSTAT
MODEL THT1248
Y
TO POWER
SUPPLY PER
LOCAL CODES
3 PH. ONLY
Component failures
• Component’s that fail after 30 days of
operation, but prematurely. A 2 year old
compressor or fan motor.
• If a component last for 100 hours of
operation, but not 10,000 hours, odds are it
is a symptom of another yet undiagnosed
problem!
Mechanical problems that cause
electrical failures
• Failure of start components or compressor?
Compressor starting with liquid present!
• Overcharged unit.
• Crankcase heater circuit failure.
• Cycle rate too short, superheat never
stabilizing.
• Low supply voltage is the least common,
and most often assumed.
Things we need to get better at
• Gathering information from the consumer.
• Looking beyond the failure in front of us, why
did it fail. Shit does not just happen!
• Charging, letting the system run long enough to
stabilize. Taking subcooling and superheat.
• Remembering that over 50% of the electronic
controls replaced didn’t need to be replaced!
The MOST important thing to
remember
Trane technicians are proven
to be the best!
The End
Thank you