Mitsubishi Electric Y Series Manual page 165

OUTDOOR/HEAT SOURCE UNIT FUNCTION TABLE
IH warmer
Y-Series EP R2-Series EP WY-Series
Y-Series P R2-Series P WR2-Series
Induction heating (IH) is used to heat the refrigerant that flows back into the compressor*. This method differs from the
conventional crankcase heater method (in which a belt heater is wrapped around the outside of the compressor) in that
heat is not applied from the outside; the refrigerant is heated from the inside, thus eliminating wasted heat.
* Normally, the compressor is heated while the outdoor unit is stopped to prevent liquid refrigerant from remaining in the compressor and to evaporate the liquid refrigerant in the
compressor.
*1. Power is supplied to the heater only with the 22HP and 24HP (P550 and P600) single modules
• Crankcase heater
power supply method
Metal compressor enclosure
Y-Series EP Y-Series P R2-Series
The compressor is enclosed in a metal casing
to reduce noise.
In some models, a sound absorbing material is
applied to the metal casing to further reduce
noise.
Adaptive flow control
(−18HP)
Y-Series EP
The refrigerant circuit flow adapts for both heating and cooling.
Adaptive flow control
Cooling
To indoors
• During cooling, a serial flow path (flow through two of the heat exchangers split into
three, and then through the last heat exchanger) is used. With fewer paths, the
refrigerant flow rate is increased and the heat conductivity performance is improved.
In addition, the drop in heat exchanger capacity for per path prevents the refrigerant
stagnation and improves the condensing performance of the heat exchanger during
cooling.
• During heating, a parallel flow path (flow refrigerant simultaneously through all heat
exchangers split into three) is used. By flowing the refrigerant to all paths at the heat
exchanger inlets (by increasing the number of paths compared to cooling), pressure loss
in the heat exchanger is reduced, and the evaporator performance is improved.
* Increase in evaporator performance is compared to using the original number of cooling paths.
*1
*1
Crankcase heater
EP R2-Series P
Heating
Switched
From
indoors
From
compressor
• IH power supply method
(without crankcase heater)
Heated
compressor motor
The compressor is enclosed in a
metal casing to reduce noise.
Comparison of EP300 (Y-Series)
SEER (cooling) with and without
variable path
(%)
110
100
90
80
70
60
50
Compressor
40
30
20
10
approx. 8% up
0
without with
Adaptive flow Adaptive flow
control control
165