performance data - LMCurbs

CONSTRUCTION FEATURES 

Model LQ ventilators are direct drive propeller roof fans designed to deliver large volumes of air. Nine sizes are 

available from 10" to 36" diameter. Capacities range from 135 to 14,100 CFM for exhaust ventilators and 465 to 13,500 

CFM for supply ventilators. LQ fans operate more quietly than conventional propeller roof ventilators and are 

recommended for applications requiring lower noise levels. LQ ventilators can be mounted in any position such as walls 

or sloping roofs. 

Birdscreen 

Constructed of .50” x 1.00” 

mesh heavy guage 

galvanized steel welded wire. 

Hood 

Heavy gauge aluminum 

hood with attractive low 

silhouette design. Hood is 

removable for accessibility 

to motor or propeller for 

servicing. 

Disconnect Switch 

Weather proof disconnect switch 

is factory mounted on ventilator 

base near motor terminal box, 

except for 3.00 HP units which 

use a rain-tight field mounted 

and wired disconnect switch. 

The switch is operated from 

outside of ventilator for 

maximum safety. Explosion 

proof disconnect switches are 

not mounted or wired and are 

not for outdoor use. 

Orifice 

Large streamlined 

orifice permits efficient, 

smooth air flow. 

Motor 

Motor is located in the full 

airstream which provides 

superior cooling, longer 

operation and reduces possible 

motor burn-outs from high 

ambient heat. 

All motors are totally enclosed 

type with lubricated shielded 

ball bearings. 

Steel Frame Construction 

Rugged structural steel frame 

transmits weight of the motor 

and propeller directly to 

curbcap. This eliminates any 

weight on hood, housing or 

curbcap base. Steel frame is 

finished with acrylic epoxy for 

resistance against most 

corrosive elements. 

Propeller 

Propellers feature an advanced 

tear-drop shape blade designed 

for exceptionally low noise level 

performance. 

The swept-back tear-drop blade 

shape with its aerodynamic 

leading edge propels the air 

through the streamlined orifice 

with a minimum of air turbulence. 

Aluminum blades are fastened to 

a formed steel hub with 

heavy-duty oversize rivets. The propeller is precision 

balanced for smooth vibrationless operation. 

Acme Engineering & Manufacturing Corp. certifies that the LQ Ventilators shown herein are licensed to bear the AMCA 

seal. The ratings shown are based on tests and procedures performed in accordance with AMCA Publication 211 and 

AMCA Publication 311 and comply with the requirements of the AMCA Certified Ratings Program. 

Page 2 LMCurbs Phone: 1-800-284-1412 Fax: 1-903-759-3598

Fan 

Size 

Fan 

Model 

RPM 

Tip 

Speed 

Ft./ 

Min. 

HP 

Sones 

@ 

.000" 

SP 

PERFORMANCE DATA 

LQ Exhaust Ventilators 

Approx 

Licensed CFM vs. Static Pressure 

Max. Ship Wt. 

BHP 

.000" .125" .250" .375" .500" .625" .750" .875" 1.000" 1.125" 1.250" 1.500" 1.750" 2.000" Lbs. 

10 

LQ108LO 1500 3925 .03 4.4 540 440 225 *111 19 

LQ108HI 1650 4320 .03 7.1 590 505 295 185 *111 19 

LQ12A6 1160 3590 .05 5.5 840 685 475 270 135 .054 38 

12 

LQ129LO 1350 4180 .11 6.7 975 845 695 500 335 210 .084 26 

LQ129HI 1550 4795 .11 9.7 1120 1005 885 740 565 415 310 200 .128 26 

LQ12D4 1760 5445 .17 11.3 1275 1180 1070 955 820 665 520 420 325 235 155 .187 40 

LQ14C6 1160 4150 .13 9.7 1310 1155 890 640 420 .105 49 

14 LQ14E4 1760 6295 .25 15.4 1655 1565 1465 1360 1205 1000 895 790 685 590 485 .242 49 

LQ14F4 1760 6295 .33 13.5 2000 1900 1790 1670 1510 1250 1080 950 800 670 540 .366 47 

LQ16D8-1 860 3560 .17 6.1 1360 1115 635 350 .071 55 

LQ16D8-2 860 3560 .17 5.1 1525 1245 820 480 .092 55 

LQ16C6 1160 4800 .13 11.1 1840 1670 1470 1050 770 570 370 .175 55 

16 LQ16D6 1160 4800 .17 8.8 2050 1870 1650 1290 980 730 530 .225 57 

LQ16F4 1760 7280 .33 21 2290 2200 2100 1980 1830 1580 1390 1270 1150 1030 910 710 .512 53 

LQ16G4 1760 7280 .50 18.4 2790 2680 2570 2470 2320 2140 1700 1540 1360 1180 1060 800 .610 63 

LQ16H4 1760 7280 .75 16.9 3160 3010 2870 2740 2600 2440 2130 1930 1750 1550 1350 1020 .783 67 

LQ18D8-1 860 4080 .17 6.3 1940 1620 1230 850 490 .106 67 

LQ18D8-2 860 4080 .17 7.0 2400 2080 1670 1110 640 .178 67 

LQ18E6 1160 5505 .25 11.2 2620 2390 2140 1880 1530 1270 1020 810 550 .259 65 

18 LQ18G6 1160 5505 .50 11.7 3240 3000 2760 2540 2000 1660 1310 920 700 .436 79 

LQ18H4 1760 8350 .75 18.3 3970 3810 3650 3500 3340 3200 3030 2840 2580 2390 2190 1840 1530 1250 .905 79 

LQ18J4 1760 8350 1.00 18.7 4340 4190 4030 3870 3720 3560 3380 3160 2870 2620 2420 2040 1670 1310 1.085 83 

LQ18K4 1760 8350 1.50 23 4920 4780 4620 4460 4300 4120 3960 3820 3680 3120 2820 2420 1940 1460 1.530 84 

LQ21D8 860 4690 .17 8.4 2820 2510 1790 1480 1000 .190 149 

LQ21E8 860 4690 .25 8.1 3220 2760 2080 1550 1150 .252 151 

LQ21F8 860 4690 .33 9.0 3570 3120 2400 2050 1460 .331 161 

21 

LQ21G6-1 1160 6325 .50 12.8 3800 3520 3230 2780 2230 1950 1780 1490 1000 .468 161 

LQ21G6-2 1160 6325 .50 13.1 4350 4050 3720 3260 2650 2240 2020 1680 1110 .620 161 

LQ21H6 1160 6325 .75 13.5 4820 4540 4160 3700 3100 2800 2750 2140 1400 .818 165 

LQ21K4 1760 9595 1.50 26 5760 5580 5400 5210 5020 4830 4610 4300 3940 3460 3180 2880 2670 2250 1.635 166 

LQ21L4 1760 9595 2.00 25 6540 6370 6170 5960 5750 5540 5270 4830 4410 4100 3800 3280 3000 2590 2.160 165 

LQ24E8 860 5430 .25 7.6 3570 3175 2475 2010 1650 .285 172 

24 LQ24H6 1160 7325 .75 14.1 4700 4450 3980 3400 2980 2660 2380 2080 1670 1210 .700 186 

LQ24J6 1160 7325 1.00 16.9 5560 5280 4960 4600 4200 3740 3390 3130 2860 2530 2040 .997 208 

LQ30H8 860 6700 .75 19.1 7180 6780 6220 5400 4450 3970 3570 3060 2440 .837 292 

30 

LQ30J8 860 6700 1.00 14.5 9060 8520 8000 7400 6350 5300 4980 4500 3880 3120 2230 1.213 303 

LQ30L6 1160 9035 2.00 27 9450 9160 8820 8450 7970 7330 6400 5900 5580 5270 4950 4280 3500 2300 2.070 336 

LQ30M6 1160 9035 3.00 25 12000 11620 11230 10800 10400 9960 9510 8550 7620 7120 6790 6200 5510 4650 2.850 342 

36 

LQ36K8 860 8020 1.50 21 11150 10530 9870 8950 7430 6600 6300 5900 5300 1.860 409 

LQ36L8 860 8020 2.00 17.9 14100 13500 12800 12100 11000 9300 8600 8200 7700 7000 5900 2.420 415 

*Watts 

Performance shown is for installation Type A - Free inlet, Free outlet. 

Performance ratings include the effects of a birdscreen in the airstream. 

The sound level ratings shown are loudness values in fan sones at 5 

feet (1.524 m) in a hemispherical free field calculated per AMCA 

Standard 301. Values shown are for Installation Type A: Free Inlet fan 

sone levels. 

The brake horsepower capability of a fan motor is dependent of the 

degree of cooling the motor receives from the moving airstream over 

the motor. The above motor loadings do not overheat the motor and are 

within NEMA recommended limits. It is therefore not detrimental to the 

motor and is economically desirable. 


Fan 

Size 

12 

14 

16 

18 

21 

24 

30 

36 

Fan 

Model 

RPM 

Tip 

Speed 

Ft./ 

Min. 

HP 

Sones 

@ 

.000" 

SP 

PERFORMANCE DATA 

LQ Supply Ventilators 

Approx 

Licensed CFM vs. Static Pressure 

Max. Ship Wt. 

BHP 

.000" .100" .125" .250" .375" .500" .625" .750" .875" 1.000" 1.125" 1.250" Lbs. 

LQ12A6-S 1160 3590 .05 5.8 920 550 465 .050 49 

LQ12D4-S 1760 5445 .17 11.9 1395 1240 1180 835 .176 51 

LQ14B6-S 1160 4150 .08 7.1 1075 840 740 .059 52 

LQ14E4-S 1760 6295 .25 14.5 1630 1500 1460 1235 875 .210 57 

LQ16C6-S 1160 4800 .13 9.4 1790 1440 1405 .135 68 

LQ16D6-S 1160 4800 .17 11.8 1965 1440 .178 70 

LQ16F4-S 1760 7280 .33 17.8 2310 2240 2210 1790 1510 1205 .402 66 

LQ16G4-S 1760 7280 .50 18.3 2720 2530 2475 2100 1595 .476 76 

LQ16H4-S 1760 7280 .75 21 2980 2690 2625 .705 76 

LQ18D8-S 860 4080 .17 9.1 2175 1725 1620 995 .206 139 

LQ18E6-S 1160 5505 .25 12.4 2655 2410 2350 2000 1605 .320 137 

LQ18J4-S 1760 8350 1.00 23 4030 3860 3820 3615 3390 3160 2915 2665 2415 2150 1885 1620 1.130 155 

LQ18K4-S 1760 8350 1.50 34 4450 4240 4180 3920 3640 3340 3010 2690 2490 2200 1.760 156 

LQ21D8-S 860 4690 .17 8.6 2585 2245 2155 1745 1335 .216 161 

LQ21F8-S 860 4690 .33 10.4 3140 2745 2625 2000 1190 .350 173 

LQ21G6-S 1160 6325 .50 14.1 3485 3240 3175 2850 2530 2250 1950 1580 1075 .530 173 

LQ21H6-S 1160 6325 .75 19.3 4235 3925 3850 3430 3000 2535 1990 1055 .850 177 

LQ21K4-S 1760 9595 1.50 32 5270 5145 5110 4945 4755 4520 4150 3580 3280 3090 2945 2800 1.675 178 

LQ24F8-S 860 5430 .33 11.5 3750 3420 3330 2840 2275 .384 183 

LQ24H6-S 1160 7325 .75 20 5030 4790 4720 4360 3950 3580 3210 2800 .897 187 

LQ24J6-S 1160 7325 1.00 21 5550 5240 5160 4760 4360 3970 3570 3140 1.173 209 

LQ30J8-S 860 6700 1.00 19.4 6870 6400 6280 5660 4980 4120 3170 1.070 301 

LQ30K8-S 860 6700 1.50 19.7 8040 7460 7320 6620 5800 4350 3470 2280 1.570 334 

LQ30L6-S 1160 9035 2.00 30 9380 9070 9000 8590 8130 7690 7140 6550 2.380 334 

LQ30M6-S 1160 9035 3.00 34 10700 10270 10180 9750 9420 9110 8480 7690 6750 5260 3.490 340 

LQ36L8-S 860 8020 2.00 21 10550 10000 9870 9190 8500 7800 7080 6340 5530 4690 2.170 409 

LQ36M8-S 860 8020 3.00 26 13500 12980 12850 12120 11380 10570 9740 8830 7900 6920 5830 4600 3.490 426 

Performance shown is for installation Type A - Free inlet, Free outlet. 

Performance ratings include the effects of a birdscreen in the airstream. 

The sound level ratings shown are loudness values in fan sones at 5 

feet (1.524 m) in a hemispherical free field calculated per AMCA 

Standard 301. Values shown are for Installation Type A: Free Outlet fan 

sone levels. 

The brake horsepower capability of a fan motor is dependent of the 

degree of cooling the motor receives from the moving airstream over the 

motor. The above motor loadings do not overheat the motor and are 

within NEMA recommended limits. It is therefore not detrimental to the 

motor and is economically desirable. 


OPTIONAL ACCESSORIES 

Solid State Controller 

Solid state controllers are available for the 

ventilators equipped with 115 volt, single 

phase, shaded pole and the smaller size 

permanent split-capacitor motors. They 

provide a variable speed control and are 

easily installed in a standard wall box. 

They require only a simple 2 wire connection but are 

equipped with a third wire that maintains a constant voltage 

to the damper motor in the event a motorized backdraft 

damper is used with the ventilator. 

Backdraft Dampers 

Prefabricated Curbs 

Heavy gauge galvanized steel or aluminum curbs for easy 

installation of exhauster over roof opening. Replaces 

conventional field constructed curbs for steel, concrete or 

wood roofs. 

Type RF - Roofed-over type features built-in cant strip to 

accommodate roofing materials for flashing up over top of 

curb. Wood nailer is standard except on Model CR curbs. 

Type SF - Self-flashing type features wide base flange for 

easy flashing to roof. This eliminates need for extending 

roofing material up over top of curb. ¼" polystyrene gasket 

is standard. 

Large oversized design provides for lower air velocity and 

quieter operation. All aluminum multi-blade construction. 

Precision balanced full opening blades with nylon bearings. 

The double tie rods reduce flutter. Exhaust dampers 

available as automatic or motorized; supply dampers 

available as motorized only. 

Damper Box 

A box type adapter for 

easy installation of 

damper. Fits inside the 

prefabricated or field 

constructed curb. Required 

for installation of damper in 

an Acme prefabricated 

curb. 

CURB DIMENSIONS 

DAMPER 

DAMPER 

BOX 

FAN 

SIZE 

MODEL J K N M H LQ LQ-S MODEL 

10 C20.5x20.5x8 28.50 20.50 17.50 14.50 8.00 AR14 ⎯ DB14LQ 

12 C22.5x22.5x8 30.50 22.50 19.50 16.50 8.00 AR16 WAGC16 DB16LQ 







36 C51x51x8 59.00 51.00 48.00 45.00 8.00 AR44 WAGC44 DB44LQ 

Dimensions shown in inches. 


OPTIONAL COATINGS 

Coatings 

Aluminum and galvanized components remain unpainted as 

a standard finish, but when required, are processed through 

the finishing system to apply decorative or special coatings. 

A high turbulence oven is used to produce a baked on finish 

for most special coatings. Decorative coatings are not baked 

on. 

Decorative Coatings 

Acme offers 16 popular colors for decorative finishes utilizing 

an industrial grade enamel applied to the exterior of the fan. 

Special colors are available upon request. See your Acme 

Representative for complete color selections. 

Special Coatings 

Products receiving special coatings have components 

painted before assembly. Fasteners are not painted. 

• Acrylic Epoxy 

This product provides a more durable surface. 

• Carboline Sanitile 

(Eisenheiss) 

This air dry synthetic polyester forms a black coating that 

offers greater resistance to most organic and inorganic 

acids. 

• Heresite (air dry) 

A phenolic coating with greater resistance to most 

organic and inorganic acids. 

• Insulmastic 

A black asphalt based mastic that provides some 

condensation control, sound deadening and corrosion 

resistance. 

NOTE: For any coating selected the user assumes the responsibility for the corrosive agent, its concentration, 

temperature, moisture content and the ultimate effect on the coating and the equipment. 

DRAWING AND DIMENSIONAL DATA 

Typical drawings for dimensional purposes only. They are correct within limits suitable for normal installation requirements 

and do not necessarily show actual construction. Dimensions shown in inches. 

LQ &LQ-S DIMENSIONS 

Fan 

LQ LQ-S LQ LQ-S LQ LQ-S LQ LQ-S Metal Gauges 

A 

Size 

B C E F Hood Base 

10 22.08 6.61 6.61 18.63 18.63 2.36 2.36 4.41 4.41 .050 .050 

12 24.08 6.74 7.24 21.00 24.00 2.49 2.50 7.88 7.88 .050 .050 

14 26.08 8.10 9.41 24.00 27.63 3.35 4.16 8.06 8.06 .050 .050 

16 28.08 9.83 10.31 27.63 31.60 4.58 4.56 9.00 9.00 .050 .050 

18 31.08 10.76 11.84 31.60 36.00 5.01 5.22 7.42 10.66 .050 .050 

21 34.10 12.09 13.48 36.72 41.38 5.47 4.98 9.00 13.45 .050 .063 

24 38.10 13.70 13.70 41.38 41.38 5.20 5.20 11.25 11.25 .050 .063 

30 46.10 15.89 15.89 52.13 52.13 6.89 6.89 13.06 13.06 .050 .063 

36 52.50 19.00 18.67 62.38 82.00 8.13 9.67 12.75 12.81 .080 .080 


TYPICAL SPECIFICATIONS 

Low silhouette roof exhaust or supply fan shall be of a 

propeller, direct drive type. 

The precision balanced propeller shall have aluminum 

blades, die-formed with swept-back tear-drop shape and 

shall be attached to a heavy duty steel hub. 

The aluminum fan housing shall consist of a die-formed, 

double orifice for efficient airflow and a die-formed, 

aerodynamic shaped hood for less turbulent airflow. 

The acrylic epoxy finished structural steel frame shall 

transmit the weight of the motor and propeller directly to the 

curbcap/curb to prevent orifice distortion and shall allow for 

mounting in any position. 

Sealed ball bearing motors shall be adjustable on the motor 

base. 

Birdscreen shall be made from heavy duty galvanized wire. 

A disconnect device/switch shall be factory installed with a 

special weather resistant toggle cover for external operation. 

(Explosion proof not mounted or wired). 

All fans shall bear the AMCA Certified Ratings Seal for 

sound and air performance. 

Each fan shall have a permanently affixed manufacturer's 

nameplate containing the model number and serial number 

for future identification. 

Thermal overload protectors shall be available for single 

phase motors. 

Fans to be supplied with a two year limited warranty. 

Fans shall be Model LQ as manufactured by Acme 

Engineering and Manufacturing Corporation of Muskogee, 

Oklahoma. 

Most RoofMaster ® fans are listed by the 

Canadian Standards Association Testing 

Laboratory as approved. 

Most Acme RoofMaster ® fans bear the U.L. 

listing mark; consult the Acme representative 

for availability. 


CENTRIFUGAL 

EXHAUSTERS 

CEILING AND CABINET 

EXHAUSTERS 

IN-LINE CENTRIFUGAL 

FANS 

IN-LINE AXIAL FANS 

PROPELLER 

ROOF FANS 

PROPELLER 

WALL FANS 

UTILITY BLOWERS 

SUPPLY AIR FANS 

ROOF VENTS 

PLENUM FANS 

BACKWARD 

INCLINED/AIRFOIL 

CENTRIFUGAL FANS 

CENTRIFUGAL 

INDUSTRIAL 

EXHAUSTERS 

LIMITED WARRANTY Acme Engineering 

and Manufacturing Corporation extends this 

limited warranty to the original buyer and warrants 

that products supplied by the Company 

shall be free from original defects in workmanship 

and materials for two years from 

date of shipment (except for Acme’s exclusive 

duplex split pillow block bearings and shaft 5 

years from shipment, belts one year from 

shipment, and polyethylene tubing at 90 days 

from shipping), provided same have been 

properly handled, stored, installed, serviced, 

maintained and operated. Refer to Form 

MS149 for complete limited warranty terms 

and conditions. 

WARNING Acme products are designed and 

manufactured to provide reliable performance 

but they are not guaranteed to be 

100% free of defects. Even reliable products 

will experience occasional failures and this 

possibility should be recognized by the User. 

If these products are used in a life support 

ventilation system where failure could result in 

loss or injury, the User should provide adequate 

back-up ventilation, supplementary 

natural ventilation or failure alarm system, or 

acknowledge willingness to accept the risk of 

such loss or injury. 

WARNING DO NOT use in HAZARDOUS 

ENVIRONMENTS where fan’s electrical system 

could provide ignition to combustible or 

flammable materials unless unit is specifically 

built for hazardous environments. 

CAUTION Guards must be installed when fan 

is within reach of personnel or within seven (7) 

feet (2.134 m) of working level or when 

deemed advisable for safety. 

DISCLAIMER The Company has made a diligent 

effort to illustrate and describe the products 

in this literature accurately; however, such 

illustrations and descriptions are for the sole 

purpose of identification, and do not express or 

imply a warranty that the products are merchantable, 

or fit for a particular purpose, or that 

the products will necessarily conform to the illustrations 

or descriptions or dimension. 

Member Air Movement and Control Association 

LMCurbs 

P.O. Box 5299,Longview, Texas 75604 

Telephone: 800-284-1412 Fax: 903-759-0879 

www.. .lmcurbs.com email: lmcurbs@lmcurbs.com November 2002 Form C5U

Read and Save These Instructions 

FORM 613090 

INSTALLATION & MAINTENANCE INSTRUCTIONS 

Models EC, ECH, LQ, USC, USCH, and USQ 

RECEIVING AND INSPECTION 

Immediately upon receipt of a shipment, carefully inspect for 

damage and shortage. Turn propeller by hand to see that it turns 

freely and does not bind. If any damage and/or shortage is 

detected or suspected the carrier must be asked to conduct an 

inspection. The consignee’s representative should not accept 

shipment without a notation on the delivery receipt indicating 

items not delivered or apparent extent of damage. 

When a shipment is opened and damage is found which was not 

evident externally (concealed damage), it is mandatory that the 

consignee request an immediate inspection by the carrier. Report 

damage to the carrier within 15 days. Failure to report damage 

within the above time limit will cause rejection of a claim. 

HANDLING 

When handling fans and their accessories, always use equipment 

and methods that will not cause damage. Fans should be lifted 

using slings and padding or spreaders to avoid damage. 

CAUTION! Always make sure that all lifting and handling 

equipment and techniques conform to current safety standards. 

Avoid lifting fans in a way that will bend or distort fan parts. Never 

pass slings or timbers through the orifices of fan. 

CAUTION! Do not lift by the fan hood. Fans with special coatings 

or paints must be protected in handling to prevent damage. 

STORAGE 

Fans are protected against damage during shipment. If they 

cannot be installed and put into operation immediately upon 

receipt certain precautions are necessary to prevent deterioration 

during storage. Responsibility for integrity of fans and 

accessories during storage must be assumed by the user. The 

manufacturer will not be responsible for damage during storage. 

These suggestions are provided solely as a convenience to the 

user, who shall make his own decision as to whether to use any or 

all of them. 

INDOOR: The ideal storage environment for 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 at 

between 70°F and 105°F (wide temperature swings may cause 

condensation and "sweating" of metal parts). Windows should be 

covered to prevent temperature variations caused by sunlight. 

Provide thermometers and humidity indicators at several points 

and maintain the atmosphere at 40% relative humidity, or lower. 

It may be necessary to use trays of renewable desiccant or 

portable dehumidifier to remove moisture from the air in the 

storage enclosure. 

Thermostatically controlled portable heaters (vented to outdoors) 

may be required to maintain even temperatures inside the 

enclosure. 

CAUTION! Provide fire extinguishers, or fire alarms, or 

emergency response communication to protect building and 

equipment against fire damage. Be sure that building and storage 

practices meet all local, state and federal fire and safety codes. 

The following fans or accessories must be stored indoors, in a 

clean dry atmosphere: 

a. Propeller wall fans not in wall housings. 

b. Any fan protected by a cardboard carton. 

c. Motors dismounted from fans. 

d. Spare wheels or propellers. 

e. Belts, sheaves, bushings and other parts when not 

mounted on fan. 

f. Boxes, bags or cartons of hardware. 

g. Curbs 

h. Dampers 

Remove any accumulations of dirt, water, ice or snow and wipe 

dry before moving indoor storage. Allow cold parts to reach room 

temperature to avoid “sweating” of metal parts. Open boxes or 

cartons. Remove any accumulated moisture; if necessary use 

portable electric heaters to dry parts and packages. Leave 

coverings loose to permit air circulation and to permit periodic 

inspection.

Rotate wheels or propellers by hand to distribute bearing grease 

over the entire bearing surfaces. 

Store at least 3 ½” off the floor on wooden blocks covered with 

moisture proof paper or polyethylene sheathing. Provide aisles 

between parts and along all walls, to permit air circulation and 

space for inspection. 

OUTDOOR: Fans designed for outdoor use may be stored 

outdoors, if absolutely necessary. The storage area should be 

reasonably level and drained or ditched to prevent 

accumulation of water. Fencing and lighting for security are 

desirable. Roads or aisles for portable cranes and hauling 

equipment are needed. Consider the use of drift fencing to 

minimize accumulation of blowing snow or dirt. 

The following fans may be stored outdoors, if dry indoor storage 

space is not available: 

a. Fans intended for outdoor use that are crated in wood. 

b. Wall fans installed in wall housings. 

All fans must be supported on wooden blocks or timbers above 

water or normal snow levels. Provide enough blocking to 

prevent settling into soft ground. Fans should be set in place 

using the directional arrow markings on the crate as a guide. 

Locate pieces far enough apart to permit air circulation, sunlight, 

and space for periodic inspection. Place all parts on their 

supports so that rain water will run off, or to minimize water 

accumulation. Do not cover parts with plastic film or 

tarps-these cause condensation of moisture from the air 

passing through heating and cooling cycles. 

Fan wheels and propellers should be blocked to prevent 

spinning caused by strong winds. 

INSPECTION AND MAINTENANCE DURING STORAGE 

Inspect fans and accessories at least once per month, while in 

storage. Log results of inspection and maintenance performed. 

A typical log entry should include the following: 

a. Date 

b. Inspector’s Name 

c. Name of Fan 

d. Location 

e. Condition of Paint or Coating 

f. Is moisture present 

If moisture or dirt accumulations are found on parts, the source 

should be located and eliminated. Fans should be rotated at 

each inspection by hand ten to fifteen revolutions to redistribute 

the motor and bearing lubricant. 

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. The most 

critical items are pulleys, shafts and bearing locking collars. At 

the first sign of rusting on any of the above parts, remove the 

original rust preventive coating with petroleum solvent and 

clean lint-free cloths. Polish any remaining rust from surfaces 

with crocus cloth or fine emery paper and oil. Do not destroy the 

continuity of the surfaces. Wipe clean with lint-free cloths and 

recoat surfaces evenly and thoroughly with Tectly 506 (Ashland 

Oil Company) or equal. For hard to reach internal surfaces or 

for occasional use, consider using Tectly 511M Rust Preventive 

or WD40 or equal. 

REMOVING FROM STORAGE 

As fans are removed from storage to be installed in their final 

location, they should be protected and maintained in similar 

fashion, until the fan equipment goes into operation. 

INSTALLATION 

1. CAUTION! This unit has rotating parts and safety 

precautions should be exercised during installation, 

operation and maintenance. 

2. WARNING! Do not use in hazardous environments where 

the fan’s electrical system could provide ignition to 

combustible or flammable materials, unless unit is 

specifically built for hazardous environments. 

3. If the fan manufacturer prefab curb is used, a flange is 

provided for mounting the damper. Damper should be 

installed before setting the exhauster. 

4. If a damper box is being used, assemble the box and mount 

in the curb before setting the ventilator. The damper may 

be installed at this time if desired. The damper should be 

fastened to the bottom of the damper box, curb flanges or 

nailing strips in the curb. 

5. WARNING! The belt driven hood, when opened for 

maintenance, may present a hazard in winds of moderate 

to high velocity. It is therefore recommended that: 

a. Maintenance work requiring the hoods to be opened 

be performed in periods when winds are light or calm, 

if possible. 

g. Is dirt accumulated 

h. Corrective steps taken 

b. If the hood must be opened in wind, it should be 

hinged with the hood top facing away from the 

prevailing wind direction, if possible. 


c. A prop support, such as a 2” x 4” of appropriate 

length, should be placed between the opened hood 

and the fan body to prevent accidental closing. 

6. Larger units are shipped with hoods in two halves because 

of their size. See the assembly instructions (Form 613104) 

attached to the hood. 

7. Before starting, check all fasteners for tightness; 

particularly in the propeller hub. Turn the propeller by hand 

to make sure it is in alignment with the orifice and the fan 

blades do not strike. 

8. CAUTION! Before proceeding, make sure electrical 

service to fan is locked in the “OFF” position. 

9. All wiring should be in accordance with local ordinances 

and the National Electric code. 

10. WARNING! Check voltage at the fan to see if it 

corresponds with the motor nameplate. High or low voltage 

can seriously damage the motor. Extra care should be 

taken when wiring two speed motors since improper 

connections will damage motor and void motor warranty. 

On belt driven ventilators, leave enough slack in wiring to 

allow for motor movement when adjusting belt tension. 

11. Apply power momentarily and compare the rotation of the 

impeller with the directional arrow on fan. In the case of 

three phase motors, the direction can be changed by 

interchanging any two of the three motor leads. In the case 

of single phase motors, the reversing instructions will 

appear on the wiring diagram on the motor wiring 

compartment cover, or on the side of the motor. 

12. Using a minimum of eight (8) lag bolts, two (2) on each side 

near corners, securely fasten exhauster to curb, replace 

small hood and fasten all bolts securely. The fan should 

rest on the curb as level as possible. 

13. After all installation and wiring has been completed, a final 

check should be made to determine that the hood fasteners 

are tightly secured. 

14. CAUTION! Guards must be installed when fan is within 

reach of personnel or within seven (7) feet (2.134 m) of 

working level or when deemed advisable for safety. 

MAINTENANCE 

1. Under normal usage, no spare parts are recommended for 

one year of operation. Recommended spare parts are 

shown on page 4 and 5. 

2. CAUTION! Before proceeding make sure electrical service 

to fan is locked in the “OFF” position. 

WINDMILLING: Even when the power supply is locked 

out, fans may cause injury or damage if the impeller is 

subject to “windmilling” which is the turning of the impeller 

and drive components due to a draft in the system. To 

guard against this hazard, the impeller should be secured 

to physically restrict rotational movement. 

3. Motor bearings are prelubricated. Consult information 

printed on the motor for lubrication instructions. 

4. Impeller shaft bearings on belt driven units are 

prelubricated and do not require relubrication. Units with 

pillow block bearings have grease fittings and, under 

normal operating conditions, will need no required for 3 to 5 

years. If relubrication is required, use a grease conforming 

to NLGI No. 2. CAUTION! Lubricating bearings with a high 

pressure gun can blow bearing seals and overfill the 

bearing with grease. This condition can result in excessive 

churning and overheating. For normal operating conditions 

it is standard practice to fill only 30% of the bearing void 

with grease. Do not over lubricate. 

5. On belt driven units, check belt tension after the first 48 

hours of operation and there after annually. Belt should 

depress its width when pressed firmly inward at midway 

point between the pulleys. Too much tension will damage 

the bearings. Belt should be tight enough to prevent 

slippage. When replacing worn belt, replace motor pulley if 

“shoulder” is worn in groove. WARNING! Do not operate 

at speeds higher than that cataloged for this equipment. Do 

not replace motor pulley with a larger diameter pulley. Do 

not replace the fan pulley with one smaller in diameter. The 

pulley ratios are set so that the motor will not be 

overloaded. 

6. WARNING! When changing bearings, secure propeller 

with ropes or equivalent before loosening bearing set 

screws on fan shaft. 

7. If impeller shaft bearings need replacement, replace with 

bearings comparable to original equipment. If duplex split 

pillow block bearings are used, install new bearings into 

neoprene rings, check correct position of propeller with 

orifice, position bearings in die-formed recess and tighten 

screws. Replace die-formed bearing cap and tighten four 

bolts. 

NOTE: If locking collar type bearing is used, collar must first 

be positioned against inner race on bearing nearest the 

impeller and turned in direction of impeller rotation with drift 

pin and hammer until it locks. Locking collars must be on 

inboard (facing) sides of bearings. Secure bearing to shaft 

with set screw. Lock and secure other bearing to shaft in 

same manner. 

NOTE: If pillow block type bearings are used, slide 

bearings onto the shaft to desired location and bolt bearing 


lock securely to support base. Slide shaft back and forth 

in secured bearing (do not drive with hammer) and rotate 

to make certain it turns freely. Check correct position of 

propeller with inlet orifice. Then secure bearings to shaft by 

tightening set screws. 

SET SCREW TIGHTENING SCHEDULE 

1. Before initial operation of the fan, tighten set screws 

according to the procedure outlined below. 

2. After 500 operating hours or three months, whichever 

comes first, tighten set screws to the full recommended 

torque. 

3. At least once a year, tighten set screws to the full 

recommended torque. 

PROCEDURE FOR TIGHTENING SET SCREWS IN 

BEARINGS AND HUBS 

VARIABLE FREQUENCY 

DRIVES AND MOTORS 

There are occasions when a Variable Frequency Drive (VFD) 

will cause poor motor performance and possible damage. To 

avoid these problems, the Company recommends the following: 

1. Select compatible motor and VFD converter; if possible, 

the motor and the converter should be from the same 

manufacturer or at least the converter selected should be 

recommended by the motor manufacturer. 

2. A motor shaft grounding system should be used to prevent 

motor bearing damage from eddy currents. 

NOTE: The Company will not honor motor warranty claims 

if the customer fails to follow these recommendations. 

One Set Screw Application 

Using a torque wrench, tighten the set screw to the torque 

recommended in Table 1. 

Two Set Screw Application 

1. Using a torque wrench, tighten one set screw to half of the 

torque recommended in Table 1. 

2. Tighten the second set screw to the full recommended 

torque. 

3. Tighten the first set screw to the full recommended torque. 

Table 1. Recommended Tightening Torque 

for Set Screws 

Set Screw Diameter Torque (in-lbs) 

#10 35 

1/4 80 

5/16 126 

3/8 240 

7/16 384 

1/2 744 

9/16 1080 

5/8 1500 

3/4 2580 

7/8 3600 

1 5400 


Belt Drive 

Models EC, ECH, USC, USCH 

Parts List Legend 

No. Description Qty. 

1 Hood Corner Piece 4 

2 Hood Top and Slide 2 

3 Hood Center 1** 

4 Support Beam 2 

5 Support Post 4 

6 Hood Ends 2 

7 Birdscreen 1 

8 Belt* 1 

9 Fan Pulley* 1 

10 Motor Pulley* 1 

11 Motor* 1 

12 Bearing Cap 1 

13 Frame Assembly 1 

14 (HD) Propeller 1*** 

15 Propeller 1 

16 Channel Corners 4 

17 End Channels 2 

18 Hinge Bracket 4 

19 Curbcap Sides 2 

20 Curbcap Ends 2 

21 Inner Curbcap 4 

*Recommended spare parts 

** Sizes 48 through 72 require quantity of 2 

***Heavy Duty Propeller 


Direct Drive 

Models LQ & USQ 

Parts List Legend 

No. Description Qty 

1 Hood 1 

2 Propeller 1 

3 Birdscreen 1 

4 Reinforcing Piece 4 

5 Gasket 4 

6 Housing Assembly 1 

7 Frame Assembly 1 

8 Motor* 1 

9 Disconnect Switch 1 

*Recommended spare parts 


TYPICAL EXHAUST & SUPPLY VENTILATORS 

EXHAUST 

SUPPLY 

PREFABRICATED CURBS 

EXHAUST 

SUPPLY 


DESIGN CHANGES Acme reserves the right to 

make changes in design, improvements and 

additions in and to its products any time without 

imposing any liability or obligations to itself to 

apply or install the same in any product manufactured 

by it. 

TERMS AND CONDITIONS 

TITLE The title and right of possession of the 

equipment sold herein shall remain with the 

Company and such equipment shall remain 

personal property until all payments herein (including 

deferred payments whether evidenced 

by notes or otherwise) shall have been made in 

full in cash and the Purchaser agrees to do all 

acts necessary to perfect and maintain such 

right and title in the Company. 

SAFETY ACCESSORIES The Company manufactures 

equipment designed to serve multiple 

applications and offers a wide range of safety 

equipment, including guards and other devices, 

as may be required to meet customer specifications. 

Without exception, the Company recommends 

that all orders include applicable safety 

devices. Equipment ordered without applicable 

safety devices is clearly the responsibility of the 

Purchaser. Further, the Purchaser warrants 

that he has determined and acquired any and 

all safety devices required for equipment sold 

by the Company. Weather covers and guards 

for motor and V-belt drives, couplings, shafts 

and bearings, along with inlet and outlet 

screens, are optional accessories noted in the 

price list. 

These instructions cover the usual installation, operation and maintenance methods for which the product(s) was designed. They do not purport to 

cover all details or variations in the product(s) nor to provide for every possible contingency that might be met in connection with the installation, operation 

and maintenance. For any departures from these instructions, or should particular problems arise which are not covered sufficiently for the purchaser’s 

purpose, the matter should be referred to the Company. 

WARNING Acme products are designed and manufactured to provide reliable performance but they are not guaranteed to be 100% free of defects. 

Even reliable products will experience occasional failures and this possibility should be recognized by the User. If these products are used in a life support 

ventilation system where failure could result in loss or injury, the User should provide adequate back-up ventilation, supplementary natural ventilation 

or failure alarm system, or acknowledge willingness to accept the risk of such loss or injury. 

WARNING DO NOT use in HAZARDOUS ENVIRONMENTS where fan’s electrical system could provide ignition to combustible or flammable materials 

unless unit is specifically built for hazardous environments. Comply with all local and national safety codes including the National Electrical Code (NEC) 

and National Fire Protection Act (NFPA). 

CAUTION Guards must be installed when fan is within reach of personnel or within seven (7) feet (2.134 m) of working level or when deemed advisable 

for safety. 

DISCLAIMER The Company has made a diligent effort to illustrate and describe the products in this literature accurately; however, such illustrations 

and descriptions are for the sole purpose of identification, and do not express or imply a warranty that the products are merchantable, or fit for a particular 

purpose, or that the products will necessarily conform to the illustrations or descriptions or dimension. 

LIMITED WARRANTY 

WARRANTY AND DISCLAIMER: Acme Engineering 

and Manufacturing Corporation extends 

this limited warranty to the original buyer and 

warrants that products supplied by the Company, 

shall be free from original defects in 

workmanship and materials for two years from 

date of shipment (except for the warranty periods 

noted for products listed below), provided 

same have been properly handled, stored, installed, 

serviced, maintained and operated. 

This warranty shall not apply to products which 

have been altered or repaired without the Company’s 

express authorization, or altered or repaired 

in any way so as, in the Company’s 

judgment, to affect its performance or reliability, 

nor which have been improperly installed or 

subjected to misuse, negligence, or accident, or 

incorrectly used in combination with other substances. 

The Buyer assumes all risks and liability 

for results of use of all products. 

Evaporative cooling pads are warranted to be 

free of defects in materials and workmanship 

for a period of two years from date of shipment 

provided same have been properly handled, 

stored, installed, serviced, maintained and operated; 

and further, not subjected to excessive 

heat, corrosive agents or chemicals, or mechanical 

abuse that may cause tearing, crushing 

or undue deterioration, nor used on a system 

or in a manner other than that for which it 

was designed as explained in the product literature. 

The following products are warranted to be free 

of defects in materials and workmanship for the 

periods shown from date of shipment: Acme’s 

exclusive duplex split pillow block bearings and 

shaft five years, belts one year, Polyethylene 

tubing 90 days, AIR40 Heater warranty one 

year, AIR40 Emitter warranty three years and 

LMCurbs 

P.O. Box 5299 

Longview, Texas 75604 

Telephone 800-284-1412 

Fax 903-759-0879 

DDP fan lifetime warranty on its propeller, cone, 

and housing. 

LIMITATION OF REMEDY AND DAMAGES: 

All claims under this warranty must be made in 

writing and delivered to P. O. Box 978, Muskogee, 

Oklahoma, 74402, within 15 days after discovery 

of the defect and prior to the expiration 

of two years from the date of shipment by the 

Company of the product claimed defective, and 

Buyer shall be barred from any remedy if Buyer 

fails to make such claim within such period. 

Within 30 days after receipt of a timely claim, 

the Company shall have the option either to inspect 

the product while in Buyer’s possession 

or to request Buyer to return the product to the 

Company at Buyer’s expense for inspection by 

the Company. The Company shall replace, or 

at its option repair, free of charge, any product 

it determines to be defective, and it shall ship 

the repaired or replacement product to Buyer 

F.O.B. point of shipment; provided, however, if 

circumstances are such as in the Company’s 

judgment to prohibit repair or replacement to 

remedy the warranted defects, the Buyer’s sole 

and exclusive remedy shall be a refund to the 

Buyer of any part of the invoice price, paid to 

the Company, for the defective product or part. 

The Company is not responsible for the cost of 

removal of the defective product or part, damages 

due to removal, or any expenses incurred 

in shipping the product or part to or from the 

Company’s plant, or the installation of the repaired 

or replaced product or part. 

Implied warranties, when applicable, shall commence 

upon the same date as the express warranty 

provided above, and shall, except for warranties 

of title, extend only for the duration of 

the express warranty. Some states do not allow 

limitations on how long an implied 

warranty lasts, so the above limitation 

may not apply to you. The only remedy 

provided to you under an applicable 

implied warranty and the express 

warranty shall be the remedy provided 

under the express warranty, 

subject to the terms and conditions 

contained therein. The Company shall not be 

liable for incidental and consequential losses 

and damages under the express warranty, any 

applicable implied warranty, or claims for negligence, 

except to the extent that this limitation is 

found to be unenforceable under applicable 

state law. Some states do not allow the exclusion 

or limitation of incidental or consequential 

damages, so the above limitation or exclusion 

may not apply to you. This warranty gives you 

specific legal rights, and you may also have 

other rights which vary from state to state. 

No employee, agent, dealer, or other person is 

authorized to give any warranties on behalf of 

the Company or to assume for the Company 

any other liability in connection with any of its 

products except in writing and signed by an officer 

of the Company. 

REPLACEMENT PARTS If replacement parts 

are ordered, buyer warrants that the original 

components in which these replacement parts 

will be placed are in satisfactory working condition, 

and when said replacement parts are installed, 

the resultant installation will operate in a 

safe manner, at speeds and temperatures for 

which the original equipment was purchased. 

TECHNICAL ADVICE AND RECOMMENDA- 

TIONS, DISCLAIMER: Notwithstanding any 

past practice or dealings or any custom of the 

trade, sales shall not include the furnishing of 

technical advice or assistance or system design. 

Any such assistance shall be at the Company’s 

sole option and may be subject to additional 

charge. 

The Company assumes no obligation or liability 

on account of any recommendations, opinions 

or advice as to the choice, installation or use of 

products. Any such recommendations, opinions 

or advice are given and shall be accepted at 

your own risk and shall not constitute any warranty 

or guarantee of such products or their 

performance. 

GENERAL In no event shall any claim for consequential 

damages be made by either party. 

The Company will comply with all applicable 

Federal, State, and local laws. 

LMCurbs Phone: 1-800-284-1412 Fax: 1-903-759-3598 December 2003 Form 613090

performance data - LMCurbs

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