ELECTRICAL WIRING
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Electricity meter connection composition
To perform energy saving peak cut control, electricity meters with pulse transmission function
measuring all the power consumed by the air conditioner are necessary. Multiple meter
installations are also possible as long as the number of electricity meters is within the specied
limit. A general electricity meter installation conguration is shown below.
Internet
Pulse unit
reference point
measurement
line
measurement
line
Pulse constant
reference point
Pulse constant
reference
point
pulse
transmission
line
pulse transmission line
CT
VT
(PT)
3ø
1ø
VT
(PT)
System Controller
System Controller
(Remote site)
Touch panel
controller
Transmission line (VRF Network)
Outdoor unit
Indoor unit
RB unit
to CN135
Power cable
Electricity meter
Electricity meter
Locally purchsed parts
▪Electricity meter
▪CT
▪VT (PT)
Item Description Remarks
Electricity meter Measures the voltage and current of the power cable to which measurement
line is connected and nds the Input Power from these. In addition, pulses
corresponding to the measured value are output to the transmission line.
VT(PT) Voltage Transformer (Power Transformer)
Transform the power source voltage to a measurable voltage. Transformation
ratio is indicated by VT (PT) ratio.
Normally unnecessary for the voltage value level used by outdoor units and
indoor units.
CT Current Transformer
Transform the power line current value to a current measurable by an
electricity meter. Transformation ratio is indicated by CT ratio.
Some meters are connected inline with the power lines and some are clamped
on the power lines.
Pulse unit Pulse unit indicates the relationship between electricity meter output pulse and
measured power. The value specied in pulse unit indicates the power in kWh
consumed on the power cable for 1 pulse.
Units: [kWh/pulse]
The value specied by pulse unit takes into account the VT and CT ratio used
and corresponds to the actual Input Power itself.
Pulse unit reference
point
Indicates the measurement point of the Input Power specied in pulse units.
Pulse constant Pulse constant indicates the relationship between electricity meter measured
power and output pulses. The value specied by pulse constant indicates
how many pulses are equivalent to 1kWh of Input Input Power to an electricity
meter.
Units: [pulse/kWh]
Because the ratio of VT and CT used is not taken into account in the value
specied by pulse constant, to nd the actual Input Power on the power cable,
the pulse constant value must be multiplied by both the VT and CT ratio.
Pulse constant
reference point
Indicates the measurement point of Input Power specied by pulse constant.
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FUNCTION
SETTING
FUNCTION
SETTING