Selection Process - Daikin UATN60CGXY1 Technical Manual

Selection Process

Selection Process
Drive Package
The following are the design requirements for UATN60C unit:
Model:
Supply Air Quantity
External Static Pressure
Step 1: From the fan curve (at 2000 CFM),
Standard operating system;
Internal Static Pressure
Step 2: Therefore at 2000 CFM and 180 Pa external static pressure,
Total Static Pressure
Step 3: From the blower curve, the design requirement calls for RPM about 1200 RPM.
From the table:
Motor pulley
Blower pulley
Motor RPM
In order to obtain 1200 RPM, we calculate the new blower pulley as:
(while maintaining the motor pulley)
Db
Let us take close approximation of 120 mm diameter pulley size
Recheck, with Db = 120 mm
Blower pulley
We thus need to change the blower pulley from 140 mm to 120 mm in order to obtain the higher operating
static pressure.
Step 4: When the pulley is changed, the V-belt length must be rechecked. We have for horizontal air throw
configuration:
V-belt length, L
We thus can use a belt with a length of 680 mm
where,
Step 5: From the blower curve, we can also notice that the motor power input has maintained within the current
operating range of the standard unit's motor.
Summary:
i) Fan motor kW
ii) Blower pulley diameter
iii) V-belt size
Note: Factory supplied rooftop is only with standard drive package.
All other changes are only given as example and need to be field supply.
UATN60C
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Dm =
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2000 CFM
180 Pa
115 Pa
180 + 115 Pa
295
Pa
100 mm
140 mm
1430
100 x (1430/1200)
119.17 mm
1430 x (100/120)
1192 RPM
2C + 1.57 (Db + Dm)
(2x165) + 1.57(120+100)
675.4
distance between the centres of the two pulleys
diameter of blower pulley
diameter of motor pulley
0.75 kW
120
mm
680 mm
17