P5417009-rev.6
47
Outdoor Unit Capacity (MBH)
72
96 - 144
168
192
216 - 432
Max. Additional Refrigerant Charge: lbs (kg)
79.4 (36)
88.2 (40)
112.5 (51)
114.7 (52)
138.9 (63)
Comply with the following conditions when installing the unit.
1. For a combination of two or three outdoor units, the outdoor unit “A” should be connected to the piping connection of
Kit 1. (Refer to Section 6.4 for outdoor unit models.) Refer to the Piping Kit Installation Manual for piping details.
2. The piping length between outdoor units should be La < Lb < Lc < 32 ft (10m).
(If the piping length is incorrect, there may be a failure of outdoor units caused by returned refrigerant.)
3. Maintain a straight-line distance of 19-11/16 inches (500mm) or more for pipe after installing the piping connection kit.
4. For the exclusive use of cooling operation only, connect indoor units with low pressure gas pipe and liquid pipe (without
Change-Over Box). The total capacity of the exclusive cooling operation should be smaller than 50% of the total indoor
unit capacity.
5. The condition of refrigerant piping installation is different depending on the number of indoor units that are connected.
Refer to Table 3.2 “System Combination” above for details.
6. Allowable total piping length may not exceed 3,281 ft (1,000m) because of the limitation of maximum additional
refrigerant amount as described in the following table. Make sure that the additional refrigerant volume does not
exceed the maximum additional refrigerant amount as shown below.
When the outdoor air temperature is 14
o
F (-10
o
C) or less, or under the high heating load conditions, the total indoor
unit capacity should be less than 100% of the outdoor unit capacity, and the total piping length should be less than
984 ft (300m).
7. If the piping length (L3) between each multi-kit and indoor unit is considerably longer than other indoor unit, refrigerant
may not flow well, and may lessen the unit’s performance compared to other models.
(Recommended Piping Length: Within 49 ft (15m))
8. When the piping length from the multi-kit to the first branch and to the terminal indoor unit exceeds 131 ft (40m), refer
to “Piping Branch Restrictions,” Section 6.5.
9. When completing on-site piping, install bent piping or horizontal loop piping to absorb any expansion or contraction
due to changing temperatures.
10. When the height difference is longer than 164 ft (50m) and up to 360 ft (110m) (in case the outdoor unit is higher, “O.U.
is Higher”), there are following restrictions.
a) Maximum outdoor temperature for cooling operation should be within 109
o
F DB (43
o
C DB).
b) When operating the outdoor unit in the outdoor air temperature approx. 14
o
F (-10
o
C) or less, the height difference
should be below 164ft (50m).
c) Maximum connectable indoor units capacity ratio must be within 100%.
d) When operating the outdoor unit under the high cooling load conditions or in the high outdoor air temperature (approx.
100
o
F (38
o
C) or more), the capacity may decrease significantly due to the compressor protection controls compared
to the installation condition of height difference below 164 ft (50m). When the outdoor air temperature is 100
o
F DB
(38
o
C DB) or more, the outdoor unit will function as Thermo-OFF to protect the compressor from failure.
e) Use of outdoor unit function setting item “nU” (Priority Capacity Mode) may be invalid.
f) Contact your distributor or contractor for details of setting.
11. When the height difference is longer than 131 ft (40m) and up to 360 ft (110m) (in case the outdoor unit is lower, “O.U.
is Lower”), there are following restrictions.
a) Maximum outdoor temperature for cooling operation should be 109
o
F DB (43
o
C DB) or less.
b) Minimum outdoor temperature for cooling operation should be 50
o
F DB (10
o
C DB) or more.
c) Minimum outdoor temperature for simultaneous operation should be 50
o
F DB (10
o
C DB) or more.
d) Contact your distributor or contractor for details of setting.
12. When the piping height difference between change-over box and indoor unit over 49 ft (15m), the performance may
decrease. (Recommended Height Difference: Within 49 ft (15m))
13. The piping length calculation is not included in the multi-kit between change-over box and indoor unit(s).
(Lm in following examples are NOT L3.)
Example
NOTICE
Indoor
Unit
Multi-Kit
Multi-Kit
Indoor
Unit
CH
L3
Lm
Indoor
Unit
Multi-Kit
Multi-Kit
Indoor
Unit
CH-M
L3
Lm