Discharge Pipe Protection Control - Daikin FCQ18PVJU Service Manual

Protection Control
4.3

Discharge Pipe Protection Control

This discharge pipe protection control is used to protect the compressor internal temperature
against a malfunction or transient increase of discharge pipe temperature.
[INV. compressor]
• HTdi>221˚F
&
• Tp>266˚F
• Not during defrost operation
(preparation ~ post operation)
or
• Not during oil return operation in heating
(preparation ~ post operation)
• Not during oil return operation in cooling
(without preparation and post operation)
In discharge pipe protection control
INV. frequency 1-step down from
current compressor frequency
(lower limit: 57Hz)
Exclusion of
the right
conditions
31
Discharge pipe protection control not limited
HTdi>230˚F
•
30 sec.
or
Tp>266˚F
•
Keep the current step
• HTdi>266˚F
or • HTdi>239˚F for 90sec. or more
Tp>284˚F
•
Fix INV. frequency 57Hz
or
Discharge pipe
temp. control standby
HTdi :Value of INV. compressor discharge pipe
temperature (Tdi) compensated with
outdoor air temperature
Tp : Value of compressor port temperature
calculated by Tc and Te, and suction
superheated degree.
• HTdi<203˚F
&
• Tp<212˚F
• INV upper limit Frequency.
• Defrost operation
(preparation ~ post operation)
or
• Oil return operation in heating
(preparation ~ post operation)
• Oil return operation in cooling
(without preparation and post operation)
INV. upper limit frequency:
1-step up from current
compressor frequency
Cooling: 20 sec.
Heating: 60 sec.
HTdi>275˚F
HTdi>248˚F for 10 min. or more.
When occurring 3 times within 100 min.,
the malfunction code "
SiUS28-902_a
HTdi<212˚F
•
&
Tp<239˚F
•
F3
" is output.
Function