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Fume Exhaust Fans

5

Installations with inlet configurations that deviate from this manual may result in reduced fan performance. Restricted 
or unstable flow at the fan inlet can cause pre-rotation of incoming air or uneven loading of the fan wheel yielding 
large system losses and increased sound levels. Free discharge or turbulent flow in the discharge ductwork will also 
result in system effect losses. Refer to the following diagrams for the most efficient installation conditions.

Ducted Inlet Installations

Inlet Duct Turns

 - Installation of a duct turn or elbow 

too close to the fan inlet reduces fan performance 
because air is loaded unevenly into the fan wheel. To 
achieve full fan performance, there should be at least 
three fan wheel diameters between the turn or elbow 
and the fan inlet.

Installation Considerations

3 fan wheel

diameters

GOOD

Turning

Vanes

POOR

Inlet Spin

 

- Inlet spin is a frequent cause of reduced 

fan performance. The change in fan performance is a 
function of the intensity of spin and not easily defined. 
The best solution is proper duct design and airflow 
patterns. Turning vanes reduce the effects of inlet spin.

R

O

T

A

T

IO

N

Turning

Vanes

GOOD

R

O

T

A

T

IO

N

POOR

Summary of Contents for VJC-200

Page 1: ...ny stationary objects 3 Motor must be securely and adequately grounded 4 Do not spin fan wheel faster than max cataloged fan RPM Adjustments to fan speed signi cantly effects motor load If the fan RPM...

Page 2: ...e which is sealed to prevent the entry of blowing dust rain or snow Temperatures should be evenly maintained between 30 to 110 F 1 to 43 C wide temperature swings may cause condensation and sweating o...

Page 3: ...age 2 3 Removing from Storage 3 General Information Unit and System Identification Tags 4 Pre Installation Information 4 Electrical Disconnects 4 Moving Parts 4 Guards Motor Cover Weatherhood 4 Access...

Page 4: ...the fan cabinet Pre Installation Information Before installation it is important to be certain the mounting surface will bear the operating weight of the unit For proper unit operation it is also impo...

Page 5: ...stallations Inlet Duct Turns Installation of a duct turn or elbow too close to the fan inlet reduces fan performance because air is loaded unevenly into the fan wheel To achieve full fan performance t...

Page 6: ...epair section of this manual for details involving touch up of damaged surfaces Lift unit before mounting the stack to the fan body Use standard lifting and rigging practices ALL lifting brackets on e...

Page 7: ...rate three common methods used to install roof curbs for fume exhaust systems Methods used to attach a unit are dependent on local codes roof construction design and roof construction materials Consul...

Page 8: ...S equipment supports are designed for use on at roof decks to be mounted directly to the roof deck structure then roofed and ashed for weather tightness The orientation of the equipment support should...

Page 9: ...osed Any increase in fan speed represents a substantial increase in load on the motor To avoid motor overheating and possible burnout motor load amperes should always be checked and compared to namepl...

Page 10: ...ts and centering the cone ring on the wheel If additional adjustment is required to maintain a constant radial gap loosening the bearing bolts and centering the wheel is acceptable as a secondary opti...

Page 11: ...al number for colors other than our standard TOUCH UP PAINT REPAIR KIT CONTENTS One pint of Kem Kromik primer including a technical data sheet One pint of industrial enamel including a technical data...

Page 12: ...ck all guarding to ensure that it is securely attached and not interfering with rotating parts 9 Check all electrical connections for proper attachment 10 Check housing and ductwork if accessible for...

Page 13: ...e entire fan should be checked for tightness 3 Any dirt accumulation on the wheel or in the housing should be removed to prevent unbalance and possible damage 4 Inspect fan impeller and housing lookin...

Page 14: ...cy Do not exceed maximum class fan rpm of the wheel Belt Span De ection Belt Span 64 Recommended Bearing Lubrication Schedule Relubrication Schedule in Months Standard Grease Fan RPM Bearing Bore inch...

Page 15: ...e nozzle preset at the factory based on the order Depending on installed air performance this nozzle can be adjusted in the eld to accommodate the building situation To increase the exhaust velocity a...

Page 16: ...ers procedures for removal and installation 3 Before removing the bearing bolts make sure the shaft is supported slightly Remember to consider the wheel weight on the shaft 4 Remove both bearings from...

Page 17: ...ake certain unit is not capable of operation during repairs CAUTION La pr sence d un moteur antid flagrant sur un ventilateur ne garantit pas que tout l appareil est antid flagrant Pour conna tre les...

Page 18: ...optional curb cap inlet box and inlet flanges Stack Motor Cover Disconnect Switch Motor Plate Motor Integrated Mounting Rails Access Door Curb Cap Isolation Damper Roof Curb Scroll Housing Inlet Cone...

Page 19: ...system Use correction factor to adjust for temperature altitude Resize ductwork Clean lters coils Change fan speed High Motor Amp Draw Fan Check rotation of wheel Reduce fan speed Duct System Resize...

Page 20: ...______ AM PM Notes __________________________________________ ________________________________________________ ________________________________________________ ________________________________________...

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