Filter
Top Products
FILE NO. SVM-03008
– 23 –
(3) Contents of operation command signal (Serial
signal) from indoor unit controller to outdoor unit
controller
The following three types of signals are sent from
the indoor unit controller.
• Operation mode set on the remote control
• Compressor revolution command signal
defined by indoor temperature and set tem-
perature (Correction along with variation of
room
temperature and correction of indoor heat
exchanger temperature are added.)
• For these two types of signals ([Operation
mode] and [Compressor revolution]), the
outdoor unit controller monitors the input
current to the inverter, and performs the
followed operation within the range that current
does not exceed the allowable value.
• Temperature of indoor heat exchanger by
indoor heat exchanger sensor
(Minimum revolution control)
(4) Contents of operation command signal (Serial
signal) from outdoor unit controller to indoor unit
controller
The following signals are sent from the outdoor
unit controller.
• The current operation mode
• The current compressor revolution
• Outdoor temperature
• Existence of protective circuit operation
For transferring of these signals, the indoor unit
controller monitors the contents of signals, and
judges existence of trouble occurrence.
Contents of judgment are described below.
• Whether distinction of the current operation
status meets to the operation command signal
• Whether protective circuit operates
When no signal is received from the outdoor
unit controller, it is assumed as a trouble.
8-1-1. Capacity control
The cooling and heating capacity is varied by changing
compressor motor speed. The inverter changes
compressor motor speed by changing
AC 220-240 V power to DC once, and controls capac-
ity by changing supply power status to the compressor
with transistor module (includes 6 transistors). The
outline of the control is as follows:
The revolution position and revolution speed of the
motor are detected by detecting winding electromotive
force of the compressor motor under operation, and
the revolution speed is changed so that the motor
drives based upon revolution speed of the operation
command by changing timing (current transfer timing)
to exchange inverter output voltage and supply power
winding.
Detection of the revolution position for controlling is
performed 12 times per 1 revolution of compressor.
The range of supply power frequency to the
compressor differs according to the operation status
(COOL, HEAT, DRY).
Table 8-1-1 Compressor revolution range
8-1-2. Current release control
The outdoor main circuit control section (Inverter
assembly) detects the input current to the outdoor unit.
If the current value with compressor motor speed
instructed from indoor side exceeds the specified
value, the outdoor main circuit control section controls
compressor motor speed by reducing motor speed so
that value becomes closest to the command within the
limited value.
8-1-3. Power factor improvement control
Power factor improvement control is performed mainly
aiming to reduce the current on much power consump-
tion of cooling/heating operation. Controlling starts
from the time when input power has reached at a
certain point. To be concrete, IGBT of the power factor
improvement circuit is used, and the power factor is
improved by keeping IGBT on for an arbitrary period to
widen electro-angle of the input current.
Operation Model
mode name
COOL
13UKV-E2
HEAT
Compressor
revolution (rps)
13 to 88
16 to 110