1 hvacr115 – mechanical for gas heat blower assemblies
TRANSCRIPT
![Page 1: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/1.jpg)
1
HVACR115 – Mechanical for Gas Heat
HVACR115 – Mechanical for Gas Heat
Blower AssembliesBlower Assemblies
![Page 2: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/2.jpg)
2
Blower AssembliesBlower Assemblies
• Are constructed to pull air through the return air ducts and filter, then push air through the heat exchanger and supply ducts.
• They require careful adjustment to produce enough volume and velocity to maintain comfort at design conditions.
• Are constructed to pull air through the return air ducts and filter, then push air through the heat exchanger and supply ducts.
• They require careful adjustment to produce enough volume and velocity to maintain comfort at design conditions.
![Page 3: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/3.jpg)
3
Blower AssembliesBlower Assemblies
• There are two types of blower assemblies available:– Direct Drive– Belt Drive
• There are two types of blower assemblies available:– Direct Drive– Belt Drive
![Page 4: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/4.jpg)
4
Direct DriveDirect Drive
• Approximately 1050 RPM on high speed.
• Motor is attached by either the blower wheel hub assembly on the shaft or through a spider coupling.
• Supported by motor shaft.
• Variable speed requires a multi-speed motor.
• Used in residential applications mainly.
• Approximately 1050 RPM on high speed.
• Motor is attached by either the blower wheel hub assembly on the shaft or through a spider coupling.
• Supported by motor shaft.
• Variable speed requires a multi-speed motor.
• Used in residential applications mainly.
![Page 5: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/5.jpg)
5
Spider CouplingSpider Coupling
![Page 6: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/6.jpg)
6
Belt DriveBelt Drive
• Motor is usually at 1725 RPM.
• Blower wheel is supported by the shaft and bearings.
• Variable speed is obtained by varying the setting of a split pulley.
• More often used on light commercial applications.
• Motor is usually at 1725 RPM.
• Blower wheel is supported by the shaft and bearings.
• Variable speed is obtained by varying the setting of a split pulley.
• More often used on light commercial applications.
![Page 7: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/7.jpg)
7
Adjustable PulliesAdjustable Pullies
![Page 8: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/8.jpg)
8
Blower AssembliesBlower Assemblies
![Page 9: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/9.jpg)
9
Belt Drive BlowersBelt Drive Blowers
• It is important that the drive on the motor and the pulley on the blower wheel be perfectly aligned.
• Any belt wear, more than normal, is most often attributed to the improper alignment of the pulley and motor.
• It is important that the drive on the motor and the pulley on the blower wheel be perfectly aligned.
• Any belt wear, more than normal, is most often attributed to the improper alignment of the pulley and motor.
![Page 10: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/10.jpg)
10
ECM and VFD MotorsECM and VFD Motors
• Today more and more manufacturers are using ECM and VFD motors to control air volume.
• Speed of the motor is directly linked to application and volume demand.
• Can compensate for air blockages.
• Today more and more manufacturers are using ECM and VFD motors to control air volume.
• Speed of the motor is directly linked to application and volume demand.
• Can compensate for air blockages.
![Page 11: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/11.jpg)
11
VFD MotorsVFD Motors
• VFD – Variable Frequency Drive remember what determines the speed of an electric motor
• Frequency of motor and the number of field poles. Rpm = (fr x 120)/NP
• If you drop the frequency you slow down the motor. i.e. a 1050 rpm motor with 30htz instead of 60htz spins at appr.600 rpms.
• If you drop the speed you drop the volume of air delivered.
• VFD – Variable Frequency Drive remember what determines the speed of an electric motor
• Frequency of motor and the number of field poles. Rpm = (fr x 120)/NP
• If you drop the frequency you slow down the motor. i.e. a 1050 rpm motor with 30htz instead of 60htz spins at appr.600 rpms.
• If you drop the speed you drop the volume of air delivered.
![Page 12: 1 HVACR115 – Mechanical for Gas Heat Blower Assemblies](https://reader035.vdocument.in/reader035/viewer/2022062721/56649f275503460f94c3e7b1/html5/thumbnails/12.jpg)
12
ECM MotorsECM Motors
• ECM – Electronically Commutated Motors.
• The motors speed is controlled by inverting the voltage from AC to DC and then sent to the motor at the amount needed for whatever speed is needed.
• ECM – Electronically Commutated Motors.
• The motors speed is controlled by inverting the voltage from AC to DC and then sent to the motor at the amount needed for whatever speed is needed.