Mitsubishi Electric Mr.SLIM PUHZ-RP1.6VHA Technical & Service Manual page 24

Applicable extension pipe for each model
The height difference between indoor and outdoor unit should be kept within 30 m for all models.
(1) 1:1 system
(a) Maximum pipe length
<Table 1> Pipe length for 1:1 system
Liquid
OD
pipe
Thick-
(mm)
ness
Gas
[9.52
OD
pipe
Thick-
t0.8
(mm)
ness
RP1.6 30m
10m
RP2
RP2.5
RP3
RP4
RP5
RP6
*1: Set DIP SW8-1 on outdoor unit controller board to ON.
*2: The maximum length is 50 m in case of using existing pipes.
[Marks in the table above]
: Standard piping
: It can be used, however, additional refrigerant charge is required when the pipe length exceeds 20m.
: It cannot be used.
: It can be used.
: It can be used, however, the capacity is lowered.
(b) Adjusting the amount of refrigerant
• Additional refrigerant charge is not necessary for the pipe length up to 30 m. When the pipe length exceeds 30 m or service
(refrigerant replacement) is performed, charge proper amount of refrigerant for each pipe length referring to table below.
Use refrigerant R410A. Use charge hose exclusive for R410A.
• When charging additional refrigerant, charge the refrigerant from low-pressure side of the port valve using a safety charger.
• Make sure that air purge for this unit at refrigerant replacement is performed from both high-pressure check valve and ser-
vice port. If air purge is performed only from one of them, air in not purged enough.
• When replacing refrigerant, charge the refrigerant from service port. When charged refrigerant is less than specified amount,
charge the refrigerant again from low pressure side of the port valve using a safety charger.
• Tighten the service port cap (nut) of stop valve firmly. The tightening torque is 12 to 16 N·m. (to prevent slow-leak)
• Check additional refrigerant charging amount referring to table 4 when liquid pipe is one size larger than standard diameter,
and table 2 when the pipe is standard diameter.
<Table 2> Additional refrigerant charging amount for pipe of standard diameter
Outdoor unit
PUHZ-RP1.6, 2VHA
PUHZ-RP2.5, 3VHA, 2.5, 3VHA
1
PUHZ-RP4 - 6VHA, RP4 - 6VHA , RP4 - 6YHA
1
<Table 3>
Outdoor unit
PUHZ-RP1.6, 2VHA
PUHZ-RP2.5, 3VHA
PUHZ-RP2.5, 3VHA
1
PUHZ-RP4-6VHA
PUHZ-RP4-6VHA
1
PUHZ-RP4-6YHA
<Table 4> Required additional charge when the pipe size is larger than the standard diameter
Liquid pipe dia Chargeless
[9.52
RP1.6, 2 20m
[12.7
RP2.5, 3 20m
[12.7
RP4-6 20m
[6.35
t0.8
[12.7 [15.88
t0.8 t1.0
50m 30m
50m 30m
10m 10m
10m 10m
Refer to (c) Capacity correction.
Additional refrigerant charging amount for pipe
Permitted
length exceeding 30 m (kg)
pipe length
31 — 40m 41 — 50m
50m or less 0.2kg 0.4kg
50m or less
0.6Kg 1.2Kg
75m or less
0.6kg 1.2kg
Recharge refrigerant amount or additional amount in parentheses
Permitted
pipe length
11 — 20m 21 — 30m
10m or below
50m or less 2.1 2.3
50m or less 3.1 3.3
75m or less 5.1 5.3
75m or less 4.6 4.8
Max. pipe length
Refrigerant amount to be added
30m
60 g per 1 m longer than 20 m
30m 100 g per 1 m longer than 20 m
50m 100 g per 1 m longer than 20 m
[9.52
t0.8
[12.7 [15.88 [19.05
t0.8 t1.0
30m (*1)
30m
30m (*1)
30m
30m 50m
30m 50m
75m (*2) 50m (*1)
75m (*2)
50m (*1)
75m (*2) 50m (*1)
51 — 60m 61 — 75m
— —
— —
1.8kg 2.4kg
31 — 40m
2.7
2.5
(0.2)
4.1
3.5
(0.6)
6.1
5.5
(0.6)
5.6
5.0
(0.6)
24
[12.7
t0.8
[15.88 [19.05
t1.0 t1.0 t1.0
30m
30m
50m 50m (*1)
50m (*1)
50m
50m (*1)
50m
Refer to <table 4>.
Number of Height
bends difference
30m or
15
above
41 — 50m 51 — 60m 61 — 75m
2.9 —
(0.4) —
4.7
—
(1.2) —
6.7
7.3
(1.2) (1.8) (2.4)
6.2 6.8
(1.2) (1.8) (2.4)
—
—
—
—
7.9
7.4