Toshiba MMU-AP0091H service manual 101

(NOTE 1) Criteria for judging difference between suction and discharge temperature

1.Cooling

After operation for a minimum of 30 minutes in [COOL] mode, check the dry bulb temperature difference. Temperature difference: 8°C or more between suction and discharge air of the indoor unit.

(In Max-Hz operation)

2.Heating

After operation for a minimum of 30 minutes in [HEAT] mode, check the dry bulb temperature difference. Temperature difference: 15°C or more between suction and discharge air of the indoor unit.

(In Max-Hz operation)

∗The temperature difference may diminish in cases of systems in which the connected indoor capacity exceeds 100%, or with long pipe length, etc.

(NOTE 2) Criteria for operating current

For a test operation (with all the indoor units operating), normal operating current is shown in the following table.

Outdoor unit	8HP	10HP	12HP
Current value	18	21	22	(Unit: A)

(NOTE 3) Criteria for cycle status

1.Refrigerating cycle under standard condition

The refrigerating cycle under standard cooling and heating condition is as follows:

					10HP
				MMY-MAP1002FT8
				Cool standard		Heat standard
Pressure	(MPa)	High	(Pd)	3.1		2.9
		Low	(Ps)	0.8		0.7
		Discharge	(TD)	86		90
		Suction	(TS1)	6		3
Pipe surface temp	(°C)	Indoor heat exchanger	(TC)	8		46
		Outdoor heat exchanger	(TE1)	43		1
		Liquid temp	(TL)	36		36
Number of compressor	(rps)	Compressor	1	79		75
rotations		Compressor	2	79		75
Air temp condition	(DB/WB) (°C)	Indoor		27/19		20/–
		Outdoor		35/–		7/6

∗This compressor is driven with 4-pole motor. The value of the compressor frequency (Hz) measured by a clamp meter is two times the rotation count (rps) of the compressor.

∗This data is the cycle data under condition of standard pipe length and two 4-way Air Discharge Cassette type air conditioners connected.

Data changes according to installed pipe length, combination of indoor units or connected indoor capacity.

∗For a compressor, the left side is 1 and the right side is 2 viewed front the front of the unit.

Even if two compressors operate, the frequency difference may set as a measures against resonance.

∗The temperature of indoor heat exchanger (TC) indicates TCJ sensor temperature in cooling time, and TC2 sensor temperature in heating time respectively.

2.Criteria for operating pressure General criteria is as follows:

All cooling operaton	High pressure : 2.0 to 3.2MPa		Indoor	:18 to 32°C	When all the units operate in cooling mode
	Low pressure	: 0.5 to 0.9MPa	Outdoor :25 to 35°C
All heating operation	High pressure : 2.5 to 3.3MPa		Indoor	:15 to 25°C	When all the units operate in heating mode
	Low pressure	: 0.5 to 0.7MPa	Outdoor : 5 to 10°C

Using the rotary switch on the outdoor unit I/F, the operating pressure, cycle temperature, and compressor rotation count can be checked on the 7-segment display.

Refer to “Outdoor refrigerant circuit system data display” and “Indoor cycle data display” in Section 9. Troubleshooting.

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