Mitsubishi Electric R410A, Руководство по обслуживанию

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[5-2 Outdoor Unit Control ]
- 97 - HWE14080 GB
5
Control
5-2-7 Defrost Operation Control
(1) Starting the defrost operation
Œ
The defrost cycle will start when all of the three conditions (outside temperature, cumulative compressor operation time, and
pipe temperature) under <Condition 1>, <Condition 2>, or <Condition 3> are met.
1) Evaporation temperature (Te)
Œ
The defrost cycle will not start if other outdoor units are in the defrost cycle or until a minimum of 10 minutes have passed
since the completion of the last defrost cycle.
Œ
If 10 minutes have passed since compressor startup or since the completion of a defrost cycle, a forced defrost cycle can be
started by setting DIP SW4(913) to ON.
Œ
Even if the defrost-prohibit timer is set to 90 minutes, the actual defrost-prohibit time for the next defrost cycle is 50 minutes
if the last defrost cycle took 12 minutes.
Œ
All units in the heating mode will simultaneously go into the defrost cycle in a system with multiple units. The units that are
not in operation may or may not go into the defrost cycle, depending on the cumulative operation time of their compressors.
(2) Defrost operation
Condition 1 Condition 2 Condition 3
Outside temperature
(TH7) -5ºC [23ºF] or above -5ºC [23ºF] or below
Cumulative compressor
operation time 50 minutes or more
90 minutes or more if the defrost prohibit timer is set to 90.
250 minutes or more
Evaporation tempera-
ture (Te) The evaporation temperature
has stayed below the tempera-
tures in the table below (Note1)
for three minutes. "Te
”
Outdoor air temperature
(TH7) x 1.1 - 7.5 ºC" or less
continues for 3 minutes
Or {(1.5+0.02 x (20+TH7) >
63LS) continues for 3 minutes}
The evaporation temperature
has stayed below the tempera-
tures in the table below (Note1)
for three minutes.
P72 P96 P120 P144 P168
SW4 (915) OFF -13 ºC -11 ºC -11 ºC -11 ºC -11 ºC
SW4 (915) ON -8 ºC -8 ºC -8 ºC -8 ºC -8 ºC
Compressor frequency Model Compressor frequency
72 model 79 Hz
96 model 79 Hz
120 model 107Hz
144 model 107Hz
168 model 129Hz
Outdoor unit fan Stopped
SV1a ON
SV5b OFF(open)
21S4a OFF
21S4b, 21S4c OFF
SV9 OFF
SV2 ON
LEV1 0 pulses
*1
*1. This value may be greater than 0 pulse depending on the 63LS and TH4 status.
LEV2a, LEV2b 3000 pulses