Panasonic Urban Multi MX1R Series Service Manual page 55

Function
1.8.2 ME1 Series
Melts frost which might collect on outdoor heat exchangers during heating in order to recover their heat
transfer performance.
Conditions for executing defrost
OR
∗ Tc : High pressure equivalent saturated temperature
T = C × (Outdoor temp.) – α
C : Tair ≤ 0°C → 0.8
∗ Tair = Outdoor air temperature
The values of ( α ) according to defrost temperature changeover switch are given in the table below.
LED (H4P, H5P, H6P, H7P)
Therefore, if outdoor temperature is 0°C:
(1) If position L, Tcoil (R2-1T, R2-2T) ≤ -12°C
(2) If position M, Tcoil (R2-1T, R2-2T) ≤ -10°C
(3) If position H, Tcoil (R2-1T, R2-2T) ≤ -8°C
Because defrost operation is carried out, set to the "H" position if frost builds up easily, and set to "L" if not.
Factory set is position "M."
34
At least 20 minutes have elapsed since completion of oil return or since compressor starts.
High pressure < 20k (Tc = 52.4ºC)
&
Compressor is running at least 30 minutes since completion of previous defrost.
Either liquid pipe thermal detection temperature (R2-1T, R2-2T) < TºC for 5 minutes.
Forced defrost test pin (MDS) is shorted.
& Liquid pipe thermal detection temperature (R2-1T, R2-2T) < 12.5ºC for all units
High pressure < 20k (Tc = 52.4ºC)
(C is constant)
Tair > 0°C → 0.6
Switch position
(deg)
L
(O OýO {) (O O { O)
12
Function Urban Multi "MX1, ME1 Series" Using R-22
PACD011001C2
M H
(O { O O)
10 8