Device Control System - Hitachi RCI-1.0FSN3 Service Manual

5 Control system

5.1 Device control system

Purpose of control
Frequency control is determined
•
Compressor control
frequency with Inverter
•
Degree of opening of the
outdoor unit expansion
valve
The control range for the degree
Degree of opening of the
indoor unit expansion
valve
Outdoor fan
4-way valve (RVR)
Solenoid valve (SVS)
(Balanced pressure valve)
•
High/low pressure balance
•
I.U.: indoor unit.
Tc/Te: condensing temperature / evaporating temperature.
Td: Discharge temperature.
Tl: liquid temperature.
Tg: gas temperature.
Cap: capacity.
182
SMGB0077 rev.0 - 01/2013
Cooling operation
with the following parameters:
Difference between the
air inlet temperature and
the set air temperature.
Calculate the width of the
change using the amount
of the change.
Fully open
of opening of the expansion
valve is determined to optimise
the difference in temperature
of the I.U. gas pipe (Tg) - the
temperature of the I.U. liquid
piping (Tl).
The fan speed operates to
control the stabilisation of the
O.U. liquid pipe temperature
(Te); (Te) stabilisation control
Off
Enabled on starting (4-10)H(V)
RNSE
Control by the indoor
expansion valve (2-3
HVRN(1)(S)
SVA activation before the
compressor is started (4-
10)H(V)RNSE
Use
Heating operation
Frequency control is determined
with the following parameters:
• Difference between the air
inlet temperature and the
set air temperature.
• Calculate the width of the
change using the amount
of the change.
The control range for the degree
of opening of the expansion
valve is determined to optimise
the temperature at the top of the
compressor.
Degree of opening specified
at the start of normal control.
Then controlled to optimise the
temperature of the I.U. liquid pipe
(Tl).
The fan speed is controlled in line
with the temperature of the O.U.
liquid pipe and the temperature at
the top of the compressor.
On
Enabled on starting (4-10)H(V)
RNSE
• Control by the outdo-
or expansion valve (2-3
HVRN(1)(S)
• SVA activation before the
compressor is started (4-
10)H(V)RNSE
Defrost mode
Fixed frequency (stop the
compressor for 30 s. once defrost
is complete).
Fully open
Specified degrees of opening
controlled by the temperature at
the top of the compressor. (Td).
Fan stoppage.
Off
Enabled by defrost