Greenheck GB User Manual

Document 471558

Model G Direct Drive

®

Model GB Belt Drive

Downblast Centrifugal Roof Exhaust

Installation, Operation and Maintenance Manual

Please read and save these instructions for future reference. Read carefully before attempting to assemble,
install, operate or maintain the product described. Protect yourself and others by observing all safety
information. Failure to comply with instructions could result in personal injury and/or property damage!

Model G Direct Drive

Model G is a direct drive downblast centrifugal
exhaust fan. These fans are specifically
designed for roof mounted applications
exhausting relatively clean air. Performance
capabilities range up to 6,300 cfm (10,703

3

m

/hr) and up to 1.75 in. wg (435 Pa) of static

pressure. The maximum continuous operating
temperature is 180°F (82ºC). G models are available
in 20 sizes with nominal wheel diameter ranging from
8 to 22 inches (203 to 558 mm) (060 - 203 unit sizes).
Each fan shall bear a permanently affixed
manufacturer’s engraved metal nameplate containing
the model number and individual serial number. All
fans are UL/cUL Listed Standard 705.

General Safety Information

Only qualified personnel should install this fan.
Personnel should have a clear understanding of these
instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock, possible injury due to coming in contact with
moving parts, as well as other potential hazards.
Other considerations may be required if high winds
or seismic activity is present. If more information is
needed, contact a licensed professional engineer
before moving forward.

1. Follow all local electrical and safety codes, as
well as the National Electrical Code (NEC) and the
National Fire Protection Agency (NFPA), where
applicable. Follow the Canadian Electric Code
(CEC) in Canada.

2. The rotation of the wheel is critical. It must be free
to rotate without striking or rubbing any 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 significantly affects
motor load. If the fan RPM is changed, the motor
current should be checked to make sure it is not
exceeding the motor nameplate amps.

5. Do not allow the power cable to kink or come in
contact with oil, grease, hot surfaces or chemicals.
Replace cord immediately if damaged.

6. Verify that the power source is compatible with the
equipment.

Model GB Belt Drive

GB model fans are belt drive downblast
centrifugal exhaust fans. These fans are
specifically designed for roof mounted
applications exhausting relatively clean
air. Performance capabilities range up
to 44,700 cfm (75,950 m

3.25 in. wg (809 Pa) of static pressure.
The maximum continuous operating temperature is
180°F (82ºC). GB models are available in 29 sizes with
nominal wheel diameters ranging from 11 to 54 inches
(279 to 1372 mm) (071-540 unit sizes). Each fan shall
bear a permanently affixed manufacturer’s nameplate
containing the model number and individual serial
number. All fans are UL/cUL Listed Standard 705.

7. Never open access doors to a duct while the fan is
running.

DANGER

Always disconnect, lock and tag power source before
installing or servicing. Failure to disconnect power
source can result in fire, shock or serious injury.

CAUTION

When servicing the fan, motor may be hot enough
to cause pain or injury. Allow motor to cool before
servicing.

CAUTION

Precaution should be taken in explosive atmospheres.

DANGER

Pour écarter les risques d’incendie, de choc
électrique ou de blessure grave, veiller à toujours
débrancher, verrouiller et étiqueter la source de
courant avant l’installation ou l’entretien.

ATTENTION

Lors de toute intervention sur la soufflante, le moteur
peut être suffisamment chaud pour provoquer une
douleur voire une blessure. Laisser le moteur refroidir
avant toute maintenance.

ATTENTION

Faire preuve de précaution dans les atmosphères
explosives.

3

/hr) and up to

®

Downblast Centrifugal Roof Exhaust 1

Receiving

Upon receiving the product, check to ensure all
items are accounted for by referencing the delivery
receipt or packing list. Inspect each crate or carton
for shipping damage before accepting delivery. Alert
the carrier of any damage detected. The customer will
make notification of damage (or shortage of items)
on the delivery receipt and all copies of the bill of
lading which is countersigned by the delivering carrier.
If damaged, immediately contact your Greenheck
Representative. Any physical damage to the unit after
acceptance is not the responsibility of Greenheck Fan
Corporation.

Unpacking

Verify that all required parts and the correct quantity
of each item have been received. If any items are
missing, report shortages to your local representative
to arrange for obtaining missing parts. Sometimes it
is not possible that all items for the unit be shipped
together due to availability of transportation and truck
space. Confirmation of shipment(s) must be limited to
only items on the bill of lading.

Figure 2

Figure 3

Screws

Hook With
Safety Latch
(Supplied by others)

(2) Bearing Plate
Lifting Points

(4) Drive Frame
Lifting Points

Screws

Handling

G Direct Drive

Lift unit on to the roof utilizing hooks under the lip
of the shroud. Evenly space the hooks around the
shroud using a minimum of four lifting straps. Use
a spreader bar to ensure the straps do not come in
contact with the unit (see Figure 1).

Figure 1

Spreader Bar

Lifting Strap

Hook

1¾ in.
(44 mm)

Curb Cap

GB Belt Drive

When lifting the unit on to the roof, use either the
four lifting points on the drive frame or the two lifting
points on the bearing plate if present (see Figure
2 for lifting points). Access to the drive frame is
accomplished by removing the screws pointed out in
Figure 3. The cover can then be removed and placed
on a flat surface in an area protected from strong
winds.

When G/GB unit is on the roof, move fan to desired
location using lifting points and fasten securely
through mounting holes in base. Shims may be
necessary depending upon roofing material thickness.

The motor amperage and voltage ratings must be
checked for compatibility to supply voltage prior to
final electrical connection. For G/GB installations, the
electrical supply should be routed through the conduit
chase located between the curb cap and the bottom
of the motor compartment. Wiring must conform to
local and national codes.

Downblast Centrifugal Roof Exhaust2

®

Storage

Fans are protected against damage during shipment.
If the unit cannot be installed and operated
immediately, precautions need to be taken to prevent
deterioration of the unit during storage. The user
assumes responsibility of the fan and accessories
while in storage. The manufacturer will not be
responsible for damage during storage. These
suggestions are provided solely as a convenience to
the user.

Indoor

The ideal environment for the storage of fans and
accessories is indoors, above grade, in a low humidity
atmosphere 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” of metal parts). All accessories must
be stored indoors in a clean, dry atmosphere.

Remove any accumulations of dirt, water, ice or snow
and wipe dry before moving to indoor storage. To
avoid “sweating” of metal parts, allow cold parts to
reach room temperature. To dry parts and packages,
use a portable electric heater to get rid of any
moisture buildup. Leave coverings loose to permit air
circulation and to allow for periodic inspection.

The unit should be stored at least 3½ inches (89 mm)
off the floor on wooden blocks covered with moisture
proof paper or polyethylene sheathing. Aisles between
parts and along all walls should be provided to permit
air circulation and space for inspection.

Inspection and Maintenance during
Storage

While in storage, inspect fans once per month. Keep a
record of inspection and maintenance performed.

If moisture or dirt accumulations are found on parts,
the source should be located and eliminated. At each
inspection, rotate the wheel by hand ten to fifteen
revolutions to distribute lubricant on motor. If paint
deterioration begins, consideration should be given
to touch-up or repainting. Fans with special coatings
may require special techniques for touch-up or repair.

Machined parts coated with rust preventive should be
restored to good condition promptly if signs of rust
occur. Immediately remove the original rust preventive
coating with petroleum solvent and clean with lint­free cloths. Polish any remaining rust from surface
with crocus cloth or fine emery paper and oil. Do not
destroy the continuity of the surfaces. Thoroughly
wipe clean with Tectyl
equivalent. For hard to reach internal surfaces or for
occasional use, consider using Tectyl
Preventive, WD-40® or the equivalent.

®

506 (Ashland Inc.) or the

®

511M Rust

Removing From Storage

As fans are removed from storage to be installed
in their final location, they should be protected and
maintained in a similar fashion until the fan equipment
goes into operation.

Table of Contents

Outdoor

Fans designed for outdoor applications may be stored
outdoors, if absolutely necessary. Roads or aisles for
portable cranes and hauling equipment are needed.

The fan should be placed on a level surface to prevent
water from leaking into the fan. The fan should be
elevated on an adequate number of wooden blocks
so that it is above water and snow levels and has
enough blocking to prevent it from settling into soft
ground. Locate parts far enough apart to permit air
circulation, sunlight and space for periodic inspection.
To minimize water accumulation, place all fan parts on
blocking supports so that rain water will run off.

Do not cover parts with plastic film or tarps as these
cause condensation of moisture from the air passing
through heating and cooling cycles.

Fan wheels should be blocked to prevent spinning
caused by strong winds.

General Safety Information ....................3

Receiving, Unpacking, Handling ................2

Storage ...................................3

Inspection and Maintenance during Storage ......3

Removing from Storage ......................3

Installation

Typical Roof Mounting Installation ............4

Typical Motor Wiring Diagram ...............4

Typical Roof Mounting Installation, Model G ....5

Typical Roof Mounting Installation, Model GB . . .5

Mounting for Severe Duty Installation ............6

Prestarting Checks ........................7-8

Operation ..................................8

Inspection .................................8

Routine Maintenance ........................9

Belt and Bearing Maintenance ...............9

Bearing Lubrication Schedule ..............10

Fan Inlet Connections .......................10

Troubleshooting ............................11

Parts List .................................12

Our Commitment ...........................12

®

Downblast Centrifugal Roof Exhaust 3

Installation

Typical Roof Mounting Installation

1. On the roof surface, cut an appropriate sized hole
and follow manufacturer’s instructions on curb
installation. Caulk and flash the curb to ensure a
water tight seal.

Roof Curb Installation

10. Check all fasteners for tightness.

11. Mount and wire safety disconnect switch under
motor cover. Wire control switches at ground
level, refer to Figure 4.

12. Replace motor cover.

Typical Wiring Diagram

MOTOR

SUPPLY VOLTAGE
115/208-230/60/1

J-BOX

L1
L2

Figure 4

Vari-Green Wiring

For Vari-Green wiring, refer to the Vari-Green
Motor and Controls Installation, Operation and
Maintenance Manual for complete wiring and
operation instructions.

MOTOR

J-BOX

SUPPLY VOLTAGE

208-230/460/60/3

L1

L2

L3

2. If unit is equipped with a backdraft damper, it
should be installed now.

3. Remove motor cover. Access to the motor
compartment is accomplished by removing the
screws as shown in Figure 3, page 2.

4. On GB Belt Drive fans, use the lifting lugs on the
drive frame or bearing plate to lift and place the
unit on top of roof curb. Refer to Figure 2, page 2.

5. On G Direct Drive fans, lift and place the unit on
top of roof curb using hooks under the lip of the
shroud. Refer to Figure 1, page 2.

6. Secure fan to curb using a minimum of eight lag
screws, metal screws or the suitable fasteners.
Shims may be required depending upon curb
installation and roofing material.

Note: Severe duty applications may require
additional fasteners. See page 6.

7. Verify power line wiring is de-energized before
connecting fan motor to power source.

8. Connect power supply wiring to the motor as
indicated on the motor nameplate or terminal box
cover. Check the power source for compatibility
with the requirements of your equipment.

9. Check fan wheel for free rotation, recenter if
necessary.

Downblast Centrifugal Roof Exhaust4

®

G Direct Drive

Figure 5 - Typical Roof Mounting Installation

GB Belt Drive

Figure 6 - Typical Roof Mounting Installation

Disconnect

Screws

¾ in.

(19)

Wiring by Others

1¼ in.

(32)

Model Curb Cap Damper

G 060, 065, 070, 075 17

Damper

Recommended Duct

and Damper Size

Recommended Roof

Opening

(432) 8 (203) 10½ (267) 18 (8)

1¼ in.

Roof

Opening

8 or 12 in.

(203 or 305)

(32)

*Approx.

Weight

G 080, 085, 090, 095 17 (432) 10 (254) 12½ (318) 26 (12)

G 097, 098, 099 19 (483) 12 (305) 14½ (368) 57 (26)

G 103, 103 HP 19 (483) 12 (305) 14½ (368) 62 (28)

G 123 19 (483) 12 (305) 14½ (368) 65 (30)

G 133 19 (483) 12 (305) 14½ (368) 66 (30)

G 143, 143 HP 22 (559) 16 (406) 18½ (470) 76 (35)

G 163 22 (559) 16 (406) 18½ (470) 80 (36)

G 183 30 (762) 18 (457) 20½ (521) 119 (54)

G 203 30 (762) 18 (457) 20½ (521) 130 (59)

• All dimensions are in inches (millimeters).

* Approximate weight shown in pounds (kilograms) is the largest

cataloged Open Drip Proof motor.

• The roof curb should be 1½ in. (38 mm) less than the curb cap to

allow for roofing and flashing.

Disconnect

¾ in.

(19)

Wiring by Others

1¼ in.

(32)

Dimensions shown in
inches (mm)

Model Curb Cap Damper

GB 071, 081, 091 19

Damper

Recommended Duct

and Damper Size

Recommended Roof

Opening

(483) 12 (305) 14½ (368) 58 (26)

Roof

Opening

8 or 12 in.

(203 or 305)

1¼ in.

(32)

*Approx.

Weight

GB 101, 101HP 19 (483) 12 (305) 14½ (368) 63 (29)

GB 121 19 (483) 12 (305) 14½ (368) 66 (30)

GB 131 19 (483) 12 (305) 14½ (368) 67 (30)

GB 141, 141HP 22 (559) 16 (406) 18½ (470) 83 (38)

GB 161, 161HP 22 (559) 16 (406) 18½ (470) 89 (40)

GB 180, 180HP 30 (762) 18 (457) 20½ (521) 125 (57)

GB 200, 200HP 30 (762) 18 (457) 20½ (521) 138 (63)

GB 220, 220HP,
240, 240HP

34 (864) 24 (610) 26½ (673) 158 (72)

GB 260 40 (1016) 30 (762) 32½ (826) 305 (138)

GB 300, 300HP 40 (1016) 30 (762) 32½ (826) 320 (145)

GB 330 46 (1168) 36 (914) 38½ (978) 385 (175)

GB 360, 360HP 46 (1168) 36 (914) 38½ (978) 403 (183)

GB 420 52 (1321) 42 (1067) 44½ (1130) 495 (225)

GB 480 52 (1321) 48 (1219) 50½ (1283) 623 (283)

GB 500 64 (1626) 54 (1372) 56½ (1435) 687 (312)

GB 540 64 (1626) 54 (1372) 56½ (1435) 748 (339)

• All dimensions are in inches (millimeters).

* Approximate weight shown in pounds (kilograms) is the largest

cataloged Open Drip Proof motor.

• The roof curb should be 1½ in. (38 mm) less than the curb cap to
allow for roofing and flashing.

®

Downblast Centrifugal Roof Exhaust 5

Mounting for Severe Duty Installations

Fan to Curb Mounting

5/16-inch self-drilling fasteners are to be installed on
each side of fan with one fastener 4 inches from each
edge and one fastener in the center. Fasteners are to
be equally spaced.

Curb to Deck Mounting

Fasteners need to be located on all four sides of the curb.

Roof Curb Roof Curb

3/8 in. (10 mm) S.S. Hilti Kwik Bolt
Three Expansion Anchors
Min. 2-1/2 in. (64 mm) Engagement

1/4 in. - 14 Self-Drilling Screw
Min. 1/2 in. (13 mm) of Threads Through

Roof Curb

Fan Size

Fasteners

Per Side

≤ 163 3

180 to 240 5

≥ 260 9

1¼ in.

(32 mm)

1¼ in.

(32 mm)

Curb Corner

Anchor Detail

Roof Curb
Model GPF, GPFHL,
GPFHD or Equivalent
18 ga. min.
High wind ratings – 42 in. Tall Max
Seismic ratings – 24 in. Tall Max
Steel Welded Construction

3/8 in. (10 mm) Lag Bolt (Zinc Plated)
Min. 3 in. (76 mm) Thread Engagement

2500 Min. PSI
Concrete

Concrete

Deck Anchoring

High Wind Ratings

Fan

Size

≤ 141

Concrete

> 141

≤ 141

Steel

> 141

≤ 141

Timber

> 141

All dimensions are in inches (millimeters).

Curb Cap Size

17x17 to 22x22

(432x432 to 559x559 mm)

26x26 to 40x40

(660x660 to 1016x1016 mm)

17x17 to 22x22

(432x432 to 559x559 mm)

26x26 to 40x40

(660x660 to 1016x1016 mm)

17x17 to 22x22

(432x432 to 559x559 mm)

26x26 to 40x40

(660x660 to 1016x1016 mm)

Steel

Deck Anchoring

Self-Drilling

Screw Size

3/8”

1/4” - 14

3/8”

Roof Truss
1/8 in. (3 mm) Thick
or 12 ga. Min.

Fasteners

Per Side

Total

Fasteners

312

312

312

416

312

416

Wood Timber
Min. 4 in. (102 mm)
Nominal Thickness
Min. G = 0.42

G: Specific Gravity
of Lumber

Timber Anchoring

Seismic Ratings

Fan Size

060-300 2 8

330-540 3 12

060-300 2 8

330-540 3 12

060-300 2 8

330-540 3 12

NOTE: Installation instructions for seismic ratings are only
recommendations.

Final design must be determined by Structural Engineer
of Record (SEOR) including requirements for curb
construction, mounting of unit to curb and mounting of
curb to structure.

Fasteners

Per Side

Total

Downblast Centrifugal Roof Exhaust6

®

Pre-Starting Checks

1. Check all fasteners and setscrews for tightness.
The wheel should rotate freely and be aligned as
shown in Figure 7.

Overlap

Figure 7

Model Size

G 060-095 – 3/32 (2)

G 097-163 1/4 (6) –

GB 071-161 1/4 (6) –

G 183-243 3/8 (10) –

GB 180-240 3/8 (10) –

GB 260-540 1/2

Overlap
in. (mm)

(13) –

2. Wheel position is preset and the unit is test run at
the factory. Movement may occur during shipment
and realignment may be necessary.

3. Only G model - Centering height alignment can
be accomplished by loosening the set screws in
the wheel and moving the wheel to the desired
position.

4. Only GB model - Centering can be accomplished
by loosening the bolts holding the drive frame
to the shock mounts and repositioning the drive
frame.

Wheel and inlet cone overlap can be adjusted by

loosening the set screws in the wheel and moving
the wheel to the desired position.

Fan RPM should be checked and verified with a

tachometer.

5. Check wheel rotation (viewing from the shaft side)
by momentarily energizing
the unit. Rotation should be
clockwise as shown in Figure
8 and correspond to rotation
decal on the unit.

If wheel rotation is incorrect,

reverse two of the wiring leads
or check motor wiring for
single phase.

Figure 8

Gap

Gap

in. (mm)

Clockwise Rotation

WARNING

Correct direction of wheel rotation is critical.
Reversed rotation will result in poor air performance,
motor overloading and possible motor burnout.

AVERTISSEMENT

La turbine doit impérativement tourner dans le bon
sens. Une rotation en sens inverse entraînerait
de mauvaises performances de soufflage, une
surcharge du moteur voire un grillage du moteur.

IMPORTANT

The fan has been checked for mechanical noises at
the factory prior to shipment. If mechanical noise
should develop, suggested corrective actions are
offered in the Troubleshooting section.

IMPORTANT

Over tightening will cause excessive bearing wear
and noise. Too little tension will cause slippage at
startup and uneven wear.

Model GB Pre-Starting Belt Tension Checks

6. Always loosen tension enough to install belts
without stretching, see Figure 9.

Do not force belt(s). Forcing the belts will break the

cords and cause belt failure.

Figure 9

7. For units with two groove pulleys, adjust so the
tension is equal in both belts.

8. If adjustments are made, it is very important to
check the pulleys for proper alignment. Misaligned
pulleys lead to excessive belt wear vibration, noise
and power loss, see Figure 10.

CORRECT WRONG WRONG WRONG

Figure 10

9. For GB units: Belt tension can be adjusted by
loosening four fasteners on the drive frame, see
Figure 11. The motor plate slides on the slotted
adjusting arms and
drive frame angles in
the same manner.

Four (4) fasteners in

total.

Identical fasteners on

opposing side must
also be loosened.

Figure 11

®

Downblast Centrifugal Roof Exhaust 7

10. Belt tension can be adjusted by loosening four
fasteners on the drive frame, see Figure 11. The
motor plate slides on the slotted adjusting arms
and drive frame angles in the same manner.

11. Sizes 071-161: Belts should be tensioned just
enough to prevent slippage at full load.

Note: Belts should have a slight bow on the slack

side while running at full load, see Figure 12a.

Deflection =

Slack
Side

Figure 12a Figure 12b

Belt Span

64

Belt

Span

Sizes 180-540: Belt tension should be adjusted

to allow 1/64 in. (0.397 mm) of deflection per inch
of belt span. For example, a 15 in. (381 mm) belt
span should have 15/64 in. (0.234 mm) (or about
1/4 in. (6 mm)) of deflection with moderate thumb
pressure at mid-point between pulleys, see
Figure 12b.

12. The adjustable motor pulley is factory set for
the RPM specified. Speed can be increased by
closing or decreased by opening the adjustable
motor pulley.

13. Any increase in speed represents a substantial
increase in the horsepower required by the unit.

14. Motor amperage should always be checked to
avoid serious damage to the motor when speed
is varied.

Operation

1. Before starting up or operating fan, check all
fasteners for tightness. In particular, check the
setscrews in wheel hub.

2. While in the OFF position or before connecting the
fan to power, turn the fan wheel by hand to be sure
it is not striking the venturi or any obstacle.

3. Start the fan and shut it off immediately to check
rotation of the wheel with directional arrow in the
motor compartment.

4. When the fan is started, observe the operation and
check for any unusual noises.

5. With the system in full operation and all ductwork
attached, measure current input to the motor and
compare with the nameplate rating to determine if
the motor is operating under safe load conditions.

6. Keep inlets and approaches to fan clean and free
from obstruction.

IMPORTANT

Adjust (tighten) belt tension after the first
24-48 hours of operation.

Inspection

Inspection of the fan should be conducted at the
first 30 minute and 24 hour intervals of satisfactory
operation.

30 Minute Interval

Inspect bolts, setscrews and motor mounting bolts.
Adjust and tighten as necessary.

24 Hour Interval

Check all internal components. On GB unit only,
inspect belt alignment and tension. Adjust and tighten
as necessary.

Downblast Centrifugal Roof Exhaust8

®

Routine Maintenance

DANGER

Disconnect and secure to the “off” position all
electrical power to the fan prior to inspection
or servicing. Failure to comply with this safety
precaution could result in serious injury or death.

DANGER

Pour écarter les risques de blessure grave ou
de mort, débrancher et verrouiller l’alimentation
électrique en position « Arrêt » avant tout contrôle
ou entretien.

IMPORTANT

Uneven cleaning of the wheel will produce an out of
balance condition that will cause vibration in the fan.

WARNING

This unit should be made non-functional when
cleaning the wheel or housing (fuses removed,
disconnect locked off).

AVERTISSEMENT

L’appareil doit être rendu non opérationnel lors
du nettoyage de la turbine ou du caisson (fusibles
retirés, sectionneur verrouillé).

Greasing of motors is only intended when fittings are
provided. Many fractional horsepower motors are
permanently lubricated and should not be lubricated
after installation. Motors supplied with grease fittings
should be greased in accordance with manufacturers’
recommendations. Where motor temperatures do not
exceed 104ºF (40ºC), the grease should be replaced
after 2,000 hours of running time as a general rule.

Wheels require very little attention when moving
clean air. Occasionally, oil and dust may accumulate
causing imbalance. When this occurs, the wheel and
housing should be cleaned to ensure smooth and safe
operation.

All fasteners should be checked for tightness each
time maintenance checks are performed prior to
restarting unit.

A proper maintenance program will help these units
deliver years of dependable service.

Belt and Bearing Maintenance for GB
Model

1. Belts tend to stretch after a period of time. They
should be checked periodically for wear and
tightness. When replacing belts, use the same
type as supplied with the unit.

2. Matched belts should always be used on units
with multi-groove pulleys.

3. For belt replacement, loosen the tensioning device
enough to allow removal of the belt by hand.

4. Once installed, adjust belts as shown in
“Pre-Starting Checks.”

5. To ensure tightness, check pulley setscrews.
Proper keys must be in keyways.

6. Fan RPM should not be readjusted. Only use
pulleys of identical size and type when replacing
pulleys.

7. Shaft bearings can be classified in two
groups: relubricating and non-relubricating. All
non-relubricating bearings on model GB fans
are factory lubricated and require no further
lubrication under normal use (between -20º
to 180ºF (-29º to 82ºC) in a relatively clean
environment).

8. On GB belt driven fans, the standard cast pillow
block bearings are factory lubricated and are
provided with external grease fittings. Annual
lubrication is recommended, or more frequently
if needed (See Table 2). Do not over-grease. Use
only one or two shots of lubricant with a hand
gun. Maximum hand gun rating is 40 psi. Rotate
bearings during lubrication where good safety
practice permits. Caution should be employed to
prevent over packing or contamination.

9. Grease fittings should be wiped clean. The unit
should be in operation while lubricating. Extreme
care should be used around moving parts.

10. Grease should be pumped in very slowly until a
slight bead forms around the seal. A high grade
lithium base grease should be used. (See Table 3)

11. During the first few months of operation,
check bearing setscrews periodically to ensure
tightness.

12. If unit is to be left idle for an extended period,
remove belts and store in a cool, dry place to
avoid premature belt failure.

®

Downblast Centrifugal Roof Exhaust 9

Recommended Bearings Lubrication
Frequency in Months

NOTE: If unusual environment conditions exist
(extreme temperature, moisture or contaminants)
more frequent lubrication is required.

A good quality lithium base grease, conforming to
NLGI Grade 2 consistency, such as those listed in
Table 3 may be used.

Table 2: Suggested Fan Bearing Lubrication Intervals

Interval

(months)

1 to 3

3 to 6

6 to 12

12 to 18 Infrequent operation or light duty in clean atmosphere

Heavy duty in dirty, dusty locations; high ambient
temperatures; moisture laden atmosphere; vibration.

12 to 24 hours per day, heavy duty, or if moisture is
present

8 to 16 hours per day in clean, relatively dry
atmosphere

Table 3: Grease Manufacturers

Manufacturer Grease (NLGI #2)

U.S. Electric Motors Grease No. 83343

Chevron U.S.A. Inc Chevron SRI Grease #2

Mobil Oil Corporation

Texaco, Inc.

Amoco Oil Co. Rykon Premium #2

Exxon Unirex N2

Shell B Shell Alvania #2

Type of Service

Mobilith

Mobil 532

Premium BRB #2

Texaco Multifak #2

Fan Inlet Connections

In order to assure proper fan performance, caution
must be exercised in fan placement and connection
to the ventilation system. Obstructions, transitions,
poorly designed elbows, improperly selected
dampers, etc., can cause reduced performance,
excessive noise and increased mechanical stress.
For performance to be as published, the system must
provide uniform and stable airflow into the fan.

Poor

Dampers must open fully.
Use motorized dampers in
low airflow applications to
reduce losses.

Good

Avoid sharp turns or
entrance conditions which
cause uneven flow. Use
turning vanes in elbows to
reduce adverse effects.

Poor

Good

Provide uniform airflow at
fan inlet and through the
damper to assure optimum
performance. The curb
cap should be three wheel
diameters from the radius.
Use turning vanes in duct
when possible.

Provide uniform airflow at
fan inlet to assure optimum
performance.

Downblast Centrifugal Roof Exhaust10

®

Troubleshooting

WARNING

Before taking any corrective action, make certain
unit is not capable of operation during repairs.

PROBLEM CAUSE CORRECTIVE ACTION

Adjust wheel and/or inlet cone. Tighten wheel hub or bearing collars
on shaft.

Tighten pulleys on motor/fan shaft. Adjust belt tension. Align pulleys
properly, see page 7, Figure 9-10. Replace worn belts or pulleys.

Replace defective bearing(s). Lubricate bearings. Tighten collars
and fasteners.

Clean all dirt off wheel. Check wheel balance, rebalance in place if
necessary.

Center wheel on inlet, see page 7, Figure 7.

Remove objects, check for damage or unbalance.

Replace motor with same frame size, RPM-HP.

Resize ductwork. Check proper operation of face and bypass
dampers. Check filters and access doors.

Check fuses/circuit breakers. Check for switches off. Check for
correct supply voltage.

Assure motor is correct horsepower and not tripping overload
protector.

Replace damaged bearing. Relieve excessive belt tension. Align
bearings. Check for bent shaft.

Check motor wiring (page 4) verify motor is wired for correct
rotation.

Check drives or slow down fan by opening variable pitch pulley on
motor shaft.

Check system: Proper operation of backdraft or control dampers,
obstruction in ductwork, clean dirty filters.

Excessive
noise
or vibration

High
horsepower

Fan does
not operate

Motor
overloads
or overheats

Reduced
airflow

Wheel rubbing inlet

V-belt drive

Bearings

Wheel unbalance

Belts too tight or too loose Adjust tension, see page 8, Figure 12a-b.
Wheel improperly aligned and

rubbing
Loose drive or motor pulleys Align and tighten. See “Pre-Starting Checks”, see page 7.
Foreign objects in wheel or

housing
Fan base not securely anchored Secure properly.
Motor hood loose and rattling Tighten screws securing motor hood.
Defective or loose motor

bearings
Fan Check rotation of wheel, see page 7, Figure 8. Reduce fan speed.

Duct system

Electrical supply

Drive Check for broken belts. Tighten loose pulleys.

Motor

Lubrication Check for excessive or insufficient grease in the bearing.

Mechanical

Belt slippage Adjust tension or replace bad belts, see page 7-8.
Over/Under line voltage Contact power company.

Incorrect wheel rotation

Wheel RPM too high

Undersized motor Check motor ratings with catalog speed and air capacity chart.
Motor wired incorrectly Check motor wiring to wiring diagram located on fan motor.

System resistance too high

Unit running backwards Correct as shown on page 7, Figure 8.
Excessive dirt buildup on wheels Clean wheel.
Improper wheel alignment Center wheel on inlets, see Pre-Starting checks on page 7, Figure 7.
Dampers closed Inspect and repair.
Blocked duct/clogged filter Clean or replace.
Belt slippage Replace and adjust tension.
Speed too slow Check for correct drives.

Avant d’entreprendre toute action corrective,
s’assurer que l’appareil ne pourra pas fonctionner
durant les réparations.

AVERTISSEMENT

®

Downblast Centrifugal Roof Exhaust 11

Parts List

Each fan bears a manufacturer’s nameplate with model number and serial number embossed. This information
will assist the local Greenheck representative and the factory in providing service and replacement parts. Before
taking any corrective action, make certain unit is not capable of operation during repairs.

CAUTION

A fan manufactured with an explosion resistant
motor does not certify the entire unit to be explosion
proof. Refer to ULListing Mark for the fans
approved usage.

La présence d’un moteur antidéflagrant sur un
ventilateur ne garantit pas que tout l’appareil est
antidéflagrant. Pour connaître les emplois autorisés
de l’appareil, voir son marquage de conformité UL.

G Direct Drive GB Belt Drive

Motor Cover

Shaft Pulley

Bearings

Drive Frame

Assembly

Shock Mounts

Shroud

Wheel

Conduit

Chase

Vertical

Support

Shock

Mounts

Shroud

Birdguard

Wheel

Curb Cap/

Venturi

Motor

Hood Clip

Shroud Brace

Vertical
Support

Lower
Windband

CAUTION

Motor Cover

Belt

Motor Pulley

Motor

Fan Shaft

Birdguard

Shroud Brace

Windband

Curb Cap/
Venturi

Our Commitment

As a result of our commitment to continuous improvement, Greenheck reserves the right to change specifications
without notice.

Specific Greenheck product warranties are located on greenheck.com within the product area tabs and in the
Library under Warranties.

Greenheck’s Centrifugal Upblast and Sidewall Exhaust
catalog provides additional information describing the
equipment, fan performance, available accessories, and
specification data.

®

Phone: [phone] • Fax: [phone] • Parts: 800.355.5354 • E-mail: [e-mail] • Website: www.greenheck.com

471558 • Model G and GB, Rev. 4, December 2014 Copyright 2014 © Greenheck Fan Corporation12

AMCA Publication 410-96, Safety Practices for Users and
Installers of Industrial and Commercial Fans, provides
additional safety information. This publication can be
obtained from AMCA International, Inc. at www.amca.org.