Symptom: General Capacity Shortage - Daikin EBLA04E V Series Service Manual

3.4.10 Symptom: General capacity shortage

Possible failure
Compressor frequency
limited - high discharge
temperature protection
function active.
Compressor frequency
limited - high pressure
protection function active.
▪ Compressor frequency
limited,
▪ Suction pipe superheat
protection function
active.
EBLA04~08E + EDLA04~08E
Daikin Altherma 3 M
ESIE22-09 – 2022.05
Root cause category: software control
Root cause
In case the discharge
temperature is higher than
105°C the compressor
frequency will be reduced.
When the discharge
temperature is lower than
105°C the frequency can
increase again.
In case high pressure is
higher than 38 bar the
compressor frequency will
be reduced. When the
pressure drops below
36 bar the compressor
frequency can increase
again.
This protection control
activates when suction
superheat is >10°C and
expansion valve is fully
open (480 pulse). Unit
returns to normal
operation when suction
superheat is <4°C.
Remark: check the suction
superheat by measuring
the suction temperature
(with contact
thermometer) before the
compressor and comparing
with the saturated
evaporation temperature.
Check
Activation of the
protection function can be
caused by various reasons,
therefore we recommend
to check the following:
▪ Check refrigerant charge,
▪ Check expansion valve
for correct operation,
▪ Check suction
thermistor,
▪ Check discharge pipe
thermistor.
Activation of the
protection function can be
caused by various reasons,
therefore we recommend
to check the following:
▪ Check refrigerant
pressure sensor,
▪ Check high pressure side
plate type heat
exchanger for good
water flow and heat
exchange,
▪ Check the refrigerant
charge.
Activation of the
protection function can be
caused by various reasons,
therefore we recommend
to check the following:
▪ Check refrigerant charge,
▪ Check expansion valve
for correct operation,
▪ Check suction
thermistor,
▪ Check the refrigerant
circuit for blockages.
draft – 31/05/2022 15:53
3 | Troubleshooting
Repair
Based on the diagnosis
execute one of the
following actions:
▪ Correct the refrigerant
charge,
▪ Replace expansion valve,
▪ Replace suction
thermistor,
▪ Replace discharge pipe
thermistor.
Based on the diagnosis
execute one of the
following actions:
▪ Replace refrigerant
pressure sensor,
▪ Optimize the water flow
through the high
pressure side plate type
heat exchanger,
▪ Correct the refrigerant
charge.
Based on the diagnosis
execute one of the
following actions:
▪ Correct the refrigerant
charge,
▪ Replace expansion valve,
▪ Replace suction
thermistor,
▪ Remove detected
blockages from
refrigerant circuit.
Service manual
the
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