Carrier X-POWER Series Service Manual page 16

Carrier service manual
1. Introduction
1.1 Model Selection Procedure
Select the model and calculate the capacity for each refrigerant system according to the procedure shown
below.
●Calculation of the indoor air-conditioning load, Calculate the maximum air-conditioning load for each
room or zone.
Selection of an air conditioning system
●Select the ideal air conditioning system for air conditioning of each room or zone
Design of the control system
●Design a suitable control system for the selected air conditioning system
Preliminary selection of indoor and outdoor units
●Make preliminary selections that are within the allowable range for the system
Check of the piping length and elevation difference
●Check that the length of refrigerant piping and the level difference are within the allowable ranges
Calculation of the corrected outdoor unit capacity
●Capacity correction coefficient for model, outdoor temperature conditions, piping length and level
difference.
Calculation of the actual capacity for each indoor unit
●Calculate the corrected indoor/outdoor capacity ratio, based on the corrected outdoor unit capacity and
the total corrected capacity of all indoor units in the same system.
Recheck of the actual capacity for each indoor unit.
●If the capacity is inadequate, reexamine the unit combinations.
1.2 Indoor Unit Selection
Enter INDOOR UNIT CAPACITY TABLES at given indoor and outdoor temperature. Select the unit that
the capacity is the nearest to and greater than given load.
Note:
Individual indoor unit capacity is subject to change by the combination. Actual capacity has to be calculated according to the
combination by using outdoor unit capacity table.
1.2.1 Calculation of Actual Capacity of Indoor Unit
Because the capacity of a multi air-conditioner changes according to the temperature conditions, piping
length, level difference and other factors, select the correct model after taking the various correction values
into account. When selecting the model, calculate the corrected capacities of the outdoor unit and each
indoor unit. Use the corrected outdoor unit capacity and the total corrected capacity of all the indoor units
to calculate the actual final capacity of each indoor unit.
Find the indoor unit capacity correction coefficient for the following items

Capacity correction for the indoor unit temperature conditions
From the graph of capacity characteristics, use the indoor temperature to find the capacity correction
coefficient.

Capacity distribution ratio based on the indoor unit piping length and level difference.
First, in the same way as for the outdoor unit, use the piping length and level difference for each
indoor unit to find the correction coefficient from the graph of capacity change characteristics
Capacity distribution ratio for each indoor unit = Correction coefficient for that indoor unit / Correction
coefficient for the outdoor unit
1.3 Outdoor Unit Selection
Allowable combinations are indicated in INDOOR UNIT COMBINATION TOTAL CAPACITY INDEX
TABLE.
In general, outdoor unit can be selected as follows though the location of the unit, zoning and usage of the
rooms may be considered.
The indoor and outdoor unit combination is determined by that the sum of indoor unit capacity index is
nearest to and smaller than the capacity index at 100% combination ratio of each outdoor unit. Up to 8~16
indoor units can be connected to one outdoor unit. It is recommended to choose a larger capacity outdoor
Selection Procedure
R410a DC Inverter 60Hz
13