Mitsubishi Electric CITY MULTI PUMY-P200YKM2R2 Technical & Service Manual page 17

4-4. CORRECTING CAPACITY FOR CHANGES IN THE LENGTH OF REFRIGERANT PIPING
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 11. Then multiply by the
cooling capacity from Figure 7 and 8 in "4-2. CORRECTION BY TEMPERATURE" to obtain the actual capacity.
During heating, find the equivalent piping length, and find the capacity ratio corresponding to standard piping length from
Figure 12. Then multiply by the heating capacity from Figure 9 and 10 in "4-2. CORRECTION BY TEMPERATURE" to
obtain the actual capacity.
(1) Capacity Correction Curve
Figure 11
[Cooling]
1.00
0.95
0.90
0.85
0.80
0.75
0.70
Figure 12
[Heating]
1.00
0.95
0.90
0.85
0.80
0.75
0.70
(2) Method for Obtaining the Equivalent Piping Length
Equivalent length = (length of piping to farthest indoor unit) + (0.3 × number of bends in the piping) (m)
4-4-1. 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 (°C W.B.)
Correction factor
OCH675E
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
0 5
Piping equivalent length (m)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Piping equivalent length (m)
6 4 2
1.00 0.98 0.89
0 −2 −4
0.88 0.89 0.90 0.95
17
Total capacity of indoor unit
11.2
16.8
22.4
29.1
Total capacity of indoor unit
Heating
P200 model
−6 −8 −10 −15
0.95 0.95 0.95
−20
0.95