Low Pressure Protection; Protection Controlling Range In Cooling / Heating Operaing Mode - Fujitsu Airstage VR-II Series Service Manual

2-9-3 Low pressure protection

Detect device
Protective function
Low pressure Low pressure
protection 1 sensor
Low pressure Low pressure
protection 2 sensor
Low pressure Low pressure
protection 3 sensor
Abnormal low Low pressure
pressure sensor
protection
control
Low pressure Low pressure
protection stop sensor
Low pressure protection - Summary -

Protection controlling range in cooling / heating operaing mode

*
S
* for a 10 Minutes
S
7 15
0.05 0.10
Note: Target pressure controlling will be cancelled when the operating pressure is in the range of orange.
Display Start condition
Cool Heat
Below 15psi (0.10MPa)
After compressor started
and 3 minutes elapsed
and Below 94psi (0.18MPa)
Below 19psi (0.13MPa)
and SH* above 50 F (10 C)
and EEV1 (EEV2) is oper-
ating with less than 52pls.
*SH = Heat-Ex1(2) Gas
temp - Low pressure
saturation temp.
Below 23psi (0.16MPa)
P3 Pattern 1
Below 7psi (0.05MPa) or
15psi (0.10MPa) for 10min.
EA51 Pattern 2
Pattern 1 generated 5
times within 180 minutes
R
R R
S
S
R
S
19 23 25 94
0.13 0.16 0.17 0.18
Release condition
3minutes elapsed and
Above 25psi (0.17MPa)
3minutes elapsed and
above 32psi (0.22MPa)
Except the start condition
3minutes elapsed and
above 94psi (0.18MPa)
3minutes elapsed and
Above 25psi (0.17Mpa)
Error reset (push button
SW) executed after power
turned on
LPP Stop : Error Indication E A 51
LP Protection1 : SV1 ON
LP protection 3: EEV1(2) set as 52 pls
*When EEV puls is less than 52 pls.
(Only heating/Heating Main)
Abnormal LP protection :
Compressor rotation speed forced cntrolling
R
LP Protection2 :
Indoor unit (Heating/ Thermo OFF) EEV
foced controlling
32 (psi)
( MPa )
0.22
02-20
Operation
SV1 =>ON
Operating Indoor unit EEV
forced controlling
-Thermo-OFF indoor unit:
450pls.
-Thermo-ON indoor unit:
gradually opens.
EEV1 (EEV2) set 52 plus
Compressor rotation speed
lessen in the limited time until
above 25psi (0.17Mpa)
(Compressor rotation speed
rise up prohibit)
Corresponding outdoor unit
stops
Corresponding outdoor unit
stops (Permanent stop) &
Error display