Defrost Operation Control - Mitsubishi Electric PURY-M200YNW-A1 Service Handbook

[5-2 Outdoor Unit Control ]
5-2-6

Defrost Operation Control

(1) Starting the defrost operation
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.
Outside temperature
(TH7)
Cumulative compressor
operation time
Pipe temperature
(TH3)
1) Pipe temperature(TH3)
SW4 (915) OFF
SW4 (915) ON
SW4 (915) OFF
SW4 (915) ON
The defrost cycle will not start until a minimum of 10 minutes have passed since the completion of the last defrost cycle.
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.
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.
14
- chapter 5
Condition 1
-5ºC [23ºF] or above
50 minutes or more
90 minutes or more if the defrost prohibit timer is set to 90.
The pipe temperature has
stayed below the temperatures
in the table below (Note1) for
three minutes.
M200 M250 M300
-8ºC -8ºC -8ºC
-5ºC -5ºC -5ºC
EM200 EM250 EM300
-8ºC -8ºC -8ºC
-5ºC -5ºC -5ºC
Condition 2
-5ºC [23ºF] or below
((E)M200-(E)M500)
The pipe temperature has
stayed below the value ob-
tained from the formula "Out-
side temperature (TH7) - 5ºC
[23ºF] " for three minutes, or the
63LS reading has stayed below
the value obtained from the for-
mula "1.5 + 0.02 x (20+TH7)"
for three minutes.
M350 M400 M450
-10ºC -10ºC
-5ºC -5ºC
EM350 EM400 EM450
-10ºC -10ºC
-5ºC -5ºC
Condition 3
250 minutes or more
The pipe temperature has
stayed below the temperatures
in the table below (Note1) for
three minutes
M500
-8ºC -8ºC
-5ºC -5ºC
EM500
-8ºC -8ºC
-5ºC -5ºC
BS_05_M