LED Trouble Flash Code Tech
Tip #2
Do not trust the Danfoss
BD 35 and BD 50 compressor Troubleshooting LED or a service
technician when they say your BD compressor has failed.
Experience shows that troubleshooting LED code signals are not
always reliable and service techs are almost always wrong about
BD compressor failures. Here are some examples representing many
reports:
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Because
the micro processor inside the Danfoss,
variable, speed compressor’s electrical control
module only has room for one trouble report at a
time, a follow up second problem can cover up a
previously stored problem. When a compressor is
running and power is interrupted ,causing a low
voltage spike, an automatic restart will occur
causing the module to terminate the start and it
will send a low voltage LED single flash every
four seconds. If the compressor attempts to
restart automatically by module before the
refrigerant pressure is reduced, an overload may
occur causing the module to now send a three LED
signal, which masks the low voltage signal. The
only way to determine if the fist signal was not
covered up is to turn off the power to the unit
and wait three minutes for pressure to equalize
before turning the unit back on while you watch
for the first LED code signal.
-
-
Danfoss
and system assemblers tell us 3 and 4 flashed
error codes of LED indicates compressor problems
with the Rotor Blocked mechanically or
Refrigerant pressure too high. After testing
many variable speed BD modules ,I now know that
there are failures inside a control module that
will trigger the 3 flash error codes even though
the refrigerant charge and compressor are fine.
Resent problems prove that poor ground
wires have triggered three flash error codes.
The most common cause of Danfoss BD compressor
three flash error codes are excessive
refrigerant charges and contaminated gas vapors,
such as air or test nitrogen which were not
properly evacuated at the company assembling
kits. Also Internet reports show most three LED
codes occur after a service technician adds too
much refrigerant.
-
-
A 5 flash
error code is supposed to be a Thermo cut-out of
the electronic control module. to Correct
replace module. Danfoss warns about module
cooling and requires an extra fan on the module
if the compressor is ever to be operated at max
speed. I believe fan cooling is important on all
water cooled units to prevent module failures.
-
See, Tech
Tip #1 conditions on Adler Barbour’s add on
circuit board which caused false three flash LED
codes when the compressor and module were
not the problem.
There are troubleshooting
items about refrigeration that most repair people don’t know
about your Adler Barbour, Frigoboat, SeaFrost or other type of
12/24 volt refrigeration units. The following points mainly
applied to Danfoss BD variable speed compressors installed after
1995.
Troubleshooting the newer
after 1995, Danfoss variable speed BD compressors when they are
equipped with troubleshooting LED is easier if the following
information is understood:
·
LED
will not signal if there is no power to Danfoss Control module.
·
LED
will not signal if thermostat circuit is open.
·
LED
will not signal if compressor is running continuously with poor
or no cooling.
·
LED
will not signal if system is low on refrigerant, the compressor
will run with little or no refrigerant and still show no LED
signal.
·
LED
will flash 3 times every 4 seconds if there is way too much
refrigerant in system.
·
On
Adler Barbour CU100 and CU200 LED will not flash when the
compressor stops due to a problem inside the add on stainless
box. This seems to be caused by poor solder connections to the
fuse holder or a damaged circuit board inside the stainless box.
·
If no
one has tampered with the refrigerant and the refrigerant flow
is blocked, the compressor will not stop nor will the LED flash,
on this type system. This is a common problem on Frigoboat keel
cooler systems. If refrigerant is added it will only cause
additional problems.
·
If
there is too much refrigerant or contaminated refrigerant, the
compressor will not start and signal with three LED flashes.
·
Unlike automobile computers Danfoss electronic module's micro
chip only has space for one memory. Because only one memory is
all that can be stored, it is possible for a second problem to
mask over the signal covering up the first LED signal. Say, the
first signal is due to a low voltage and gives a one LED flash
every 4 seconds, the compressor will stop and try to restart in
20 to 40 seconds. If the refrigerant pressure has not equalized
in this short off cycle, a restart attempt can cause a three LED
flash signal indicating an overload. When a three LED flash is
indicated, always confirm it by turning the refrigerator power
off. Then while watching the LED turn the power back on. The
first signal code you see is where the problem is located.
If you still need help
before calling a service technician, Email me your questions.
These Tech Tips are my way of keeping my books revised with
current upgrades.