Mitsubishi Electronics P500YMF-C Operating Characteristics and Refrigerant Amount, Discharge

6REFRIGERANT AMOUNT ADJUSTMENT

By clarifying the relationship between the refrigerant amount and operating characteristics for BgR2 Series, conduct service

activities such as decision on the amount and adjustment of refrigerant on the market.

[1] Operating Characteristics and Refrigerant Amount

The followings are operating characteristics and refrigerant amount which draw special attention.

1During cooling operations, required refrigerant amount tends to increase (refrigerant in accumulator decreases) in proportion to increase in the number of operating indoor units. However, the change of increase rate is small.

2During heating operations, liquid level of accumulator is the highest when all the indoor units are operating.

3Discharge temperature hardly changes when increasing or decreasing refrigerant amount with accumulator filled with refrigerant.

4		During cooling operations, discharge temperature tends to rise at
		overload than low temperature.
	Tendency of	During heating operations, discharge temperature tends to rise at	Comparison including
	discharge
		low temperature than overload.	control system
	temperature

The lower the operating frequency is, the higher the discharge temperature tends to become because of deteriorated compressor efficiency.

5Compressor shell temperature is 20 ~ 70 degrees higher than low pressure saturation temperature (TH2) when

refrigerant amount is appropriate.

→ Judged as over replenishment when temperature difference from low pressure saturation temperature (TH2) is 10 degrees or less.

[2]Adjustment and Judgement of Refrigerant Amount

(1)Symptom

The symptoms shown in the table below are the signs of excess or lack of refrigerant amount. Be sure to adjust the amount of refrigerant in refrigerant amount adjustment mode, by checking operation status, judging refrigerant amount, and performing LED monitor display with LED Dip S/W1, 1-10, for overall judgement of excess or lack of refrigerant amount.

1	Error stop at 1500 remote controller display	Excessive refrigerant replenishment
	(excessive refrigerant replenishment)
2	Operating frequency does not fully increase, thus resulting in
	insufficient capacity
3	Error stop at 1102 remote controller display	Insufficient refrigerant replenishment
	(discharge temperature trouble)
4	Error stop at 1501 remote controller display
	(low refrigerant trouble)

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