Midea MRCT-100CWN1-D(C) - Blower Drive Options; Example for Selection Process; Selection of New Desired Point

MCAC-RTT6S-201701 Midea R410A Tropical ClimaCreator Series Rooftop Package 220V 3Ph 60Hz
48
Blower drive options
Model
Motor
Blower
HP
rpm
Pulleys pitch
Dia. (inch)
Fan speed
range (rpm)
Pulleys pitch
Dia. (inch)
Min.
Max.
MRCT-100CWN1-D(C)
2.9
1,700
4.53~5.25
931
1,016
8.82
MRCT-150CWN1-D(C)
5.3
1,730
4.53~5.25
941
1,112
8.82
MRCT-200CWN1-D(C)
7.3
1,730
4.53~5.25
1,081
1,284
7.09
MRCT-250CWN1-D(C)
10
1,730
4.53~5.25
925
1,088
7.87
Example for selection process:
The following data are the rated design points for MRCT-100CWN1-D(C) rooftop packages:
Air flow =4183CFM; External static pressure = 0.3in.w.g (≈75Pa); Fan speed = 980rpm;
Power input = 1915W; The No. of turns = 1.0N.
To increase the ESP (External Static Pressure) to 0.4in.w.g (≈100Pa), but maintain the airflow rate at
4183CFM, please follow the steps below:
Step 1: Selection of new desired point.
From the table data, select the point that can meet both of the requirements.
ESP = 0.4in.w.g (≈100Pa);
Air flow rate (Near or equal to) ≈ 4183CFM.
Step 2: Read fan speed, power input:
Air flow = 4129CFM;
Fan speed = 986rpm;
Power input = 2000W.
Step 3: Read number of turns for variable pitch pulley.
Similarly, use this RPM value to read the No. of turns (N) by referring to the table of ‘Motor
Variable Pitch Pulley Data’. The variable pitch pulley for motor shall be adjusted to this ‘N’ in
order to achieve the desired point (ESP=0.4in.w.g.≈100Pa, and airflow rate=4183CFM. For
instance, from the table, No. of turns (N) = 0.5 in order to get 4129CFM. First, adjust the