Mitsubishi Electronics MUZ-ANA Cold air prevention control, MSZ-A09/12/15/17, Overload starting

(2) Cold air prevention control

MSZ-A09/12/15/17

1When the compressor is not operating,

(1) if the temperature of room temperature thermistor RT11 is less than 66°F, the fan stops.

(2) if the temperature of room temperature thermistor RT11 is 66°F or more and (1) if the temperature of RT12 is less than 32°F, the fan stops.

(2) if the temperature of RT12 is 32°F or more, the fan operates at Very Low.

2When the compressor is operating,

(1) if the temperature of RT12 is 104°F or more, the fan operates at set speed.

(2) if the temperature of RT12 is less than 104°F and

(1) if heating operation starts after defrosting, the fan stops.

(2) if the temperature of room temperature thermistor RT11 is 66°F or less, the fan stops.

(3) if the temperature of room temperature thermistor RT11 is more than 66°F, the fan operates at Very Low.

NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the temperature of RT11 and RT12.

MSZ-A24

1When the compressor is not operating,

(1) if the temperature of room temperature thermistor RT11 is 59°F or less, or RT12 is less than 64°F, the fan stops.

(2) if the temperature of room temperature thermistor RT11 is more than 59°F, or RT12 is more than 64°F, the fan operates at Very Low.

2When the compressor is operating,

(1) if the temperature of RT12 is 64°F or more, the fan operates at set speed.

(2) if the temperature of RT12 is less than 64°F and

(1) if heating operation starts after defrosting, the fan stops.

(2) if the temperature of room temperature thermistor RT11 is 59°F or less, the fan stops.

(3) if the temperature of room temperature thermistor RT11 is more than 59°F, the fan operates at Very Low.

NOTE : When 3 minutes have passed since the compressor started operation, this control is released regardless of the temperature of RT11 and RT12.

3. Overload starting

When the room temperature thermistor RT11 reads 64°F or more, the compressor runs with its maximum frequency regulated for 10 minutes after the start-up.

4.Defrosting

(1)Starting conditions of defrosting

When the following conditions a) ~ c) are satisfied, the defrosting starts.

a)The defrost thermistor reads 27°F or less.

b)The cumulative operation time of the compressor has reached any of the set valuesw (40, 45, 55, 65, 75, 85, 95, 105, 115, 125, 150 minutes(MUZ-A09/12/15/17))/(31,35,45,55,65,75,85,95,105,115,150minutes(MUZ-A24)).

c)More than 5 minutes have passed since the start-up of the compressor.

wSet value of compressor operation time (here in after referred to as defrost interval)

This is decided by the temperature of defrost thermistor and ambient temperature thermistor, the previous defrosting time. For example, the first defrost interval is 40 minutes long, and the second is 45 minutes long. The third and subse-

quent intervals are set to be longer, and less frequent, depending on defrosting time.

The third and subsequent defrost intervals follow any of the three patterns …5 or 10 to 20 minutes longer, the same, or 5 or 10 to 20 minutes shorter compared with the previous defrost interval … with the longest 125 minutes and the shortest 40 minutes.

(2)Releasing conditions of defrosting

Defrosting is released when any of the following conditions is satisfied:

a)The defrost thermistor continues to read 50°F or more (MUZ-A09/12) / 41°F or more (MUZ-A15/17) / 59°F or more (MUZ-A24) for 30 seconds.

b)Defrosting time has exceeded 10 minutes.

c)Any other mode than HEAT mode is set during defrosting.

8