High Pressure Control; Pulse Modulating Valve (P .M.v.) Control - Toshiba RAS-25PKVSG-ND Service Manual

Item

12. High pressure control

Cooling Heating
(TE) (TC)
63°C
62°C
63°C 57°C
61°C 55°C
59°C 53°C
55°C 49°C
This function controls throttle amount of the
13. Pulse
Modulating refrigerant in the refrigerating cycle.
valve (P.M.V.)
According to operating status of the air conditioner,
control
this function also controls the open degree of valve
with an expansion valve with pulse Modulation.
Starting up
Initialize
Move to
initial position
SH control
PMV open degree control
Compressor Stop by
Turn OFF by
"Room Temperature
remote controller
Move to "Stop
Position" (Setup
from factory)
* SH (Super Heat amount) =
Ts (Temperature of suction pipe of the compressor) –
Tc or Te (Heat exchanger temperature at evaporation side)
* PMV: Pulse Modulating Valve
Operation flow and applicable data, etc.
Control operation
Compressor ON
Td, high pressure
release control
Defrosting
operation
Control"
Move to "Defrost
Position" (Setup
from factory)
1. Purpose
This function detects error on the
refrigerating cycle or error on the com-
pressor, and performs protective control.
2. Operation
- TE or TC sensor control
- Control of the compressor speed The
speed control is performed as described in
the left table.
- High pressure switch control compressor
are shut down when discharge pressure
(Pd) reaches or exceeds 4.15
- The compressor restart prevention timer
(3 min) is set, and the control terminated.
1) When starting the operation, move the
valve once until it fits to the stopper.
(Initialize)
* In this time, "Click" sound may be
heard.
2) Adjust the open degree of valve by super
heat amount. (SH control)
3) If the discharge temperature was exces-
sively up, adjust the open degree of valve
so that it is in the range of set tempera-
ture. (Discharge temp. control)
4) When defrost operation is performed, the
open degree of valve is adjusted accord-
ing to each setup conditions during
preparation for defrost and during defrost
operation (4-way valve is inversed.).
5) When operation is OFF by the remote
controller or when compressor is OFF by
room temperature control, the open
degree of valve is adjusted to the stop
position.
- 38 -
FILE NO. SVM-17057
Description
MPa
+0
-0.3