Bradford White RE2H50R10 - Manuel (Page 2)

Electronic Expansion Valve (EEV)
This valve replaces the capillary tube typically used in
refrigeration appliances. The EEV meters the flow of liquid
refrigerant entering the evaporator at the rate that matches
the amount of refrigerant being boiled off in the evaporator
(gas). the valve also maintains the proper “superheat”
(T3b-T3a).
Superheat is the temperature of a gas above the boiling point
for the liquid. If a refrigerant liquid boils at a temperature of
40ºF in a cooling coil, and then the refrigerant gas increases
in temperature, superheat has been added. If this refrigerant
changed from a liquid to a gas or vapor at 40ºF and then the
refrigerant vapor increased in temperature to 50ºF, it has been
superheated by 10ºF.
Fault Codes
Fault Code
Displayed
Condition Check
FA
Control checks to ensure compressor discharge temperature is rising
when the compressor starts running. T4 sensor (compressor outlet
temperature) must rise at least 20F during the first 30 minutes of run
time.
Check T4 sensor mounting, wiring and resistance.
Check Electronic Expansion Valve (EEV) operation.
Check sealed system for refrigerant leak.
Fb
Control checks to ensure compressor discharge temperature is stable
while the compressor is running. Continuously verifies that T4 sensor
(compressor outlet temperature) is greater than 120F after 30 minutes
of run time.
Check T4 sensor mounting, wiring and resistance.
In cold climates, insulate T4 sensor with mastic.
Check Electronic Expansion Valve (EEV) operation.
Check sealed system for refrigerant leak.
In cold climates, recommend Hybrid or High Demand mode.
FC
Control checks to ensure evaporator is free of frost. Continuously veri-
fies that T3a sensor (evaporator inlet temperature) is greater than 20F
after 30 minutes of run time.
Check T3a sensor mounting, wiring and resistance.
Check Electronic Expansion Valve (EEV) operation.
Check sealed system for refrigerant leak.
Fd
Control checks to ensure evaporator superheat* is OK (controlled by
EEV). Continuously verifies the temperature difference between T3a
sensor (evap inlet temp) and T3b sensor (evap outlet temp) is greater
than 5F after 30 mins of run time. Control also verifies that T3a is
greater than 10F less than T5 ambient sensor.
Check that filter is clean.
Check T3a, T3b and T5 sensor mounting, wiring and resist-
ance.
Check Electronic Expansion Valve (EEV) operation.
Check sealed system for refrigerant leak.
FE
Control checks to ensure the compressor discharge temperature never
exceeds 240F. Continuously verifies that T4 sensor (compressor outlet
temperature) is less than 240F every minute of run time.
Check T4 sensor mounting, wiring and resistance.
Check Electronic Expansion Valve (EEV) operation.
Check sealed system for refrigerant leak.
FF
Control checks to ensure the EEV is operating properly and valve rota-
tion is within range.
Check Electronic Expansion Valve (EEV) operation.
Check T3a and T3b sensors mounting, wiring and resistance.
Check sealed system for refrigerant leak.
FG* Control checks to ensure Ambient temperature is within an acceptable
range before starting heat pump. Heat pump
operating range is 45ºF < [T5 ambient] <120ºF. If ambient temperature
(as viewed by T5 sensor) is outside of this
range, the unit will switch to Electric/Standard Mode for that heat-
ing cycle only. NO fault code is shown on the display. Note that the
compressor and fan may run for 3 minutes to assess true ambient
temperature.
No failure is assumed, but this information is provided for
completeness.
FH* Control checks to ensure the compressor load does not exceed a
threshold sufficient to trip the compressor current/temperature over-
load device. It is preferred that the software move the unit into Electric/
Standard Mode rather than tripping the compressor overload device
repeatedly. The logic employs a lookup table to accomplish this, but
a basic summary is: If {T5 ambient temperature range is [90ºF-120ºF]
AND Compressor Current > [3.2 to 3.8A] or T5 ambient temperature
range is [45ºF to 90ºF] AND Compressor Current > 5.5A } then the
control switches operating mode to Electric/Standard for the current
heating cycle, and the FH counter is increased by one. The total FH
count can be viewed in the diagnostics mode, BUT the control will NOT
display a fault code.
Since no fault code is displayed for the Run Condition H, the
fault count information is provided solely to help the techni-
cian
ascertain if the control sees these high ambient
temperature/high current conditions on a regular basis or not.
F I* Control checks to ensure evaporator superheat is <20ºF AND the EEV
position is <450 after 30 minutes of run time. If outside these limits,
this provides an early indication of a refrigerant leak. (Note: Target
superheat is generally 10ºF, and EEV generally operates at a position
much lower than 450.)
Check sealed system for refrigerant leak.
Check T3a, T3b, T5 sensor mounting, wiring and resistance.
Check Electronic Expansion Valve (EEV) operation.
F2
T2 tank temperature sensor failure Just before compressor starts,
control checks T2 sensor is within 30F - 170F temperature range.
Check T2 sensor mounting, wiring and resistance.
Use service mode to monitor T2 sensor temperature.
Control assembly may have failed.
F3
Compressor failure
Control energizes compressor, but current sensor detects no current
flow.
Check compressor start capacitor.
Check compressor, overloads, relay and wiring.
Use service mode to manually cycle compressor on/off.
F4 Fan failure Check fan and wiring.
F5
T3a sensor (evap inlet temperature) failure. The control detects the
thermistor output is at or nearly shorted or open circuit.
Check T3a sensor mounting, wiring and resistance.
Use service mode to monitor T3a sensor temperature.
Control assembly may have failed.
F6
T3b sensor (evap outlet temperature) failure. The control detects the
thermistor output is at or nearly shorted or open circuit.
Check T3b sensor mounting, wiring and resistance.
Use service mode to monitor T3b sensor temperature.
Control assembly may have failed.
F7
T4 sensor (compressor outlet) failure. The control detects the thermis-
tor output is at or nearly shorted or open circuit.
Check T4 sensor mounting, wiring and resistance.
Use service mode to monitor T4 sensor temperature.
Control assembly may have failed.
F8
T5 sensor (ambient temperature) failure. The control detects the ther-
mistor output is at or nearly shorted or open circuit.
Check T5 sensor mounting, wiring and resistance.
Use service mode to monitor T5 sensor temperature.
Control assembly may have failed.
F9 Lower heating element failure. Control energizes lower element, but
current sensor detects no current flow.
Check lower heating element and wiring.
Use service mode to cycle element and check current draw.
Control assembly may have failed.
F10 Upper heating element failure. Control energizes Upper element, but
current sensor detects no current flow.
Check Upper heating element and wiring.
Use service mode to cycle element and check current draw.
Control assembly may have failed.
F11
Dry Tank fault. This test is run within the first 7 minutes after the unit
has powered on. The compressor is engaged for 5 minutes (after a 2
minute wait for the system to ensure the pressures are stabilized) and
the tank temperature, T2, is read and verified it has not risen over 3.5
deg F. If it has, this indicates there is not enough water in the tank for
safe operation.
Check to ensure the tank is full of water.
Check T2 sensor mounting, wiring and resistance.
Use service mode to monitor T2 sensor temperature.
Control assembly may have failed.
bAd linE
(F12)
The voltage is too low at power-up. The control monitors the input line
voltage 5 seconds after power-up, and if the voltage is below 155V, the
fault code will be displayed.
Check electrical supply line connections. Voltage should
measure either 208 VAC or 240 VAC, depending upon power
supply. Badline counts stored in “F12” and can be monitored
via the Control when placed in diagnostics mode.
F13
Stuck Key fault. This indicates there is a button on the front panel that
is stuck down. This button is inoperable. Other buttons work normally.
If the button becomes free, the fault code will clear by itself.
Check to see if all buttons are operable.
Control assembly has failed
DirtyFilter
(F14)
Filter LED is on, and audible alarm is sounding. Filter is too dirty to
enable proper function of unit. Number of “Dirty Filter” counts are
stored in the “F14” code and can be monitored via the Control when it is
placed in Diagnostics Mode.
Check to ensure Filter is clean. Filter cleaning instructions are
found in the owner’s manual.
F15 DataFlash fault. The microcontroller has detected a problem in the
DataFlash (permanent memory storage).
Control assembly may have failed.
*on some models
EEV
CONDENSER COIL
(Non-replaceable)
CAPACITOR VERSION
FAN SHROUD
EVAPORATOR COIL
CAPACITOR VERSION
10 11
13
BLACK
BLACK
YELLOW
BLUE
BROWN
START
CAPACITOR
FAN
TCO
6 Ω 10 Ω
6 Ω 20 Ω
10
YELLOW
BLUE
BROWN
MAIN
BOARD
MAIN
BOARD
FAN
TCO
T5
T2
T3
A
B3
T
T4
V
E
E
COMP LE
UE DLB
COMPRESSOR
TCO
170°F
UPPER ELEMENT
T3a
T3b
T4
T2
NO NO
NO NO
COM COM COM COM
NC
NC
L1
L2
E
G
N
A
R
O
YELLOW
K
NI
P
VIOLET
T5
(ambient)
BLACK
RED
LOWER ELEMENT
4500W 12.8 Ω ~ 18.75 A
4500W 12.8 Ω ~ 18.75 A
N
W
O
R
B
N
W
O
R
B
W
O
R
B
N
YELLOW
OPTION 1
YELLOW
OPTION 2
BLUE
GRAY
CT101
FA
N
R
OT
A
R
O
P
A
V
E
K202 K204
K203 K201
1
2
3
4
WIRING DIAGRAM
Comp_N
o
Y
A
R
G
BLUE
238-50804-00A 31-75034 03-14