Mitsubishi Electronics PURY-P400, P500YMF-C specifications 145, Lps

Note 1 Wait until the units stabilize as described in the refrigerant amount adjustment procedure in “Chapter 6”.

Note 2 After the units are operating stably, check that the refrigerant composition of α OC is within the following

ranges, indicating that the composition check is finished.
If the accumulator liquid level AL = 0 when cooling:	α OC = 0.20 ~ 0.26
If the accumulator liquid level AL = 1 when cooling:	α OC = 0.23 ~ 0.34
When heating:	α OC = 0.25 ~ 0.34

(The self-diagnosis switch (SW1) on the main board of the outdoor unit can be used to display this data on the LED.)

[α OC self-diagnosis switch]

1 2 3 4 5 6 7 8 9 10

ON

Note 3 TH2 and TH9:	Check and make any corrections using the same method as that for a faulty temperature
	sensor, (refer to TROUBLESHOOTING).
LPS:	Check and make any corrections using the same method as that for a faulty low pressure
	sensor, (refer to TROUBLESHOOTING).
CS circuit block:	Set the self-diagnosis switch on the outdoor MAIN board as shown below.

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ON

•Check and make any corrections so that “0” is displayed.

•If any number other than 0 is displayed and TH2, TH9 or LPS are malfunctioning, correct them, then set SW2-9 on the MAIN board of the outdoor unit from OFF to ON.

•If any number other than 0 is displayed and TH2, TH9 or LPS are not malfunctioning, replace the CS circuit if refrigerant is not flowing through it (while operating) and set SW2-9 on the MAIN board of the outdoor unit from OFF to ON.

Note 4 If it can be verified that R407C was correctly charged in the liquid phase, continue to Yes. If there is a possibility that it was not charged correctly, such as with a gas charger, continue to No.

Note 5 After reclaiming the system’s refrigerant, extract the air to create a vacuum, then refill with new refrigerant. Be sure to charge in the liquid phase. In addition, be sure to change the dryer.

Note 6 After the units are operating stably, check that the refrigerant composition of α OC is within the following

ranges, indicating that the circulation check is finished.
If the accumulator liquid level AL = 0 when cooling:	α OC = 0.21 ~ 0.25
If the accumulator liquid level AL = 1 when cooling:	α OC = 0.24 ~ 0.28
When heating:	α OC = 0.27 ~ 0.31

If the refrigerant composition of α OC is not within the ranges specified above, a large error has been detected. Refer to section 1-3 in Chapter 6, then after setting SW4-1 on the MAIN board of the outdoor unit to ON, calibrate the refrigerant circulation constant α OC with SW4-2 until it is within the ranges specified above.

After calibrating, keep the SW4-1 ON and finish the circulation check. <Example calibration of the refrigerant circulation constant α OC>

Conditions: If the accumulator liquid level AL = 0 and α OC = 0.29 when cooling, α OC must be adjusted so

that it is between 0.21 and 0.25.

By switching SW4-2 between ON and OFF, adjustments can be made in the following order: 0 → 3% → 6% → 9% → 12% → -6% → -3% → 0

For this example, by making an adjustment of -0.06 (-6%), α OC can be adjusted to 0.23.

1.	If SW4-2 is already set to OFF, change the switch 5 times.
	OFF (0.29) →	ON (0.32)	→	OFF (0.35) →	ON (0.38)	→	OFF (0.41) →	ON (0.23)
2.	If SW4-2 is already set to ON, change the switch 5 times.
	ON (0.29) →	OFF (0.32)	→	ON (0.35) →	OFF (0.38)	→	ON (0.41) →	OFF (0.23)

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