Correcting Capacity For Changes In The Length Of Refrigerant Piping; Capacity Correction Curve; Method For Obtaining The Equivalent Piping Length; Correction Of Heating Capacity For Frost And Defrosting - Mitsubishi Electric PUMY-P112VKM1 Service Manual

4-4-2. Correcting Capacity for Changes in the Length of Refrigerant Piping

(1) During cooling, obtain the ratio (and the equivalent piping length) of the outdoor units rated capacity and the total in-use
indoor capacity, and find the capacity ratio corresponding to the standard piping length from Figure 3. Then multiply by
the cooling capacity from Figure 1 to obtain the actual capacity.
(2) During heating, find the equivalent piping length, and find the capacity ratio corresponding to standard piping length from
Figure 3. Then multiply by the heating capacity from Figure 2 to obtain the actual capacity.

(1) Capacity Correction Curve

Figure 3
1.00
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0 20

(2) Method for Obtaining the Equivalent Piping Length

Equivalent length for type P112·125·140 = (length of piping to farthest indoor unit) + (0.3 o number of bends in the piping) (m)
Length of piping to farthest indoor unit: type P112 to P140.....150 m

4-4-3. Correction of Heating Capacity for Frost and Defrosting

If heating capacity has been reduced due to frost formation or defrosting, multiply the capacity by the appropriate correction
factor from the following table to obtain the actual heating capacity.
Correction factor diagram
Outdoor Intake temperature (W.B.°C)
Correction factor
OCH576
40 60 80 100
Corrected pipe length
6 4 2
1.0 0.98 0.89
120 140 160
−2 −4
0
0.88 0.89 0.9 0.95
20
Heating P112, 125, 140
models
Cooling P112 model
Cooling P125 model
Cooling P140 model
[m]
180 200
−6 −8 −10 −15
0.95 0.95 0.95
Cooling
Heating
−20
0.95