Sterling TC User Manual

INSTALLATION INSTRUCTIONS AND PARTS IDENTIFICATION

TUBULAR GAS-FIRED BLOWER STYLE UNIT HEATER

ATTENTION: READ THIS MANUAL AND ALL LABELS ATTACHED TO THE UNIT CAREFULLY BEFORE
ATTEMPTING TO INSTALL, OPERATE OR SERVICE THESE UNITS! CHECK UNIT DATA PLATE FOR TYPE OF GAS
AND ELECTRICAL SPECIFICATIONS AND MAKE CERTAIN THAT THESE AGREE WITH THOSE AT THE POINT OF
INSTALLATION. RECORD THE UNIT MODEL AND SERIAL No.(s) IN THE SPACE PROVIDED. RETAIN FOR FUTURE
REFERENCE.

TBII-3

J30-08867

Unit No.

Serial No.

FOR YOUR SAFETY

The use and storage of gasoline or other fl ammable vapors and liquids in open containers in
the vicinity of this appliance is hazardous.

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FOR YOUR SAFETY

If you smell gas:

1. Open windows.

2. Don't touch electrical switches.

3. Extinguish any open fl ame.

4. Immediately contact your gas supplier.

V

E

CM

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ENERGY

PERFORMANCE

VERIFIED

RENDEMENT

ENERGETIQUE

VERIFIE

Improper installation, adjustment, alteration, service, or maintenance
can cause property damage, injury, or death. Read the installation, operating, and
maintenance instruction thoroughly before installing or servicing this equipment.

APPROVED FOR USE IN CALIFORNIA

APPROVED FOR USE IN CALIFORNIA

Install, operate, and maintain unit in accordance with the manufacturer's
instructions to avoid exposure to fuel substances, or substances from incomplete
combustion, which can cause death or serious illness. The state of California
has determined that these substances may cause cancer, birth defects, or other
reproductive harm.

08/13

INSTALLER'S RESPONSIBILITY

Installer Please Note: This equipment has been test fired and inspected. It has been

shipped free from defects from our factory. However, shipment and installation
problems such as loose wires, leaks, or loose fasteners may occur. It is the installer's

responsibility to inspect and correct any problem that may be found.

RECEIVING INSTRUCTIONS

Inspect shipment immediately when
received to determine if any damage
has occurred to the unit during
shipment. After the unit has been
uncrated, check for any visible
damage to the unit. If any damage
is found, the consignee should sign
the bill of lading indicating such
damage and immediately file claim
for damage with the transportation
company.

260 NORTH ELM ST., WESTFIELD, MA 01085

TEL: [phone] FAX: [phone]

www.mestek.com

TABLE OF CONTENTS

DESCRIPTION………………. ....................................... 2

GENERAL SAFETY INFORMATION
Installation Codes………………………………… 2, 3
Special Precautions………………………………. 2, 3

PERFORMANCE AND DIMENSIONAL DATA .............. 4

INSTALLATION
Locating Units………………………………………… 5
Combustion Air……………………………………… . 5
Heat Throw Data……………………………………. . 6

Clearances…………………………………….. ......... 7

Suspension of Units………………………………. ....7

Gas Piping……………………………………… ........ 8

Pipe Installation……………………………………. ... 9

BLOWER SET UP AND ADJUSTMENT……………...10

NOTICE: It is the equipment owners responsibility to provide any scaffolding or other apparatus required to
perform emergency service or annual/periodic maintenance to this equipment.

MOTOR AND PULLEY .............................................. 11

ELECTRICAL CONNECTIONS…………………. ...12-16

VENTING ..............................................................17-21

OPERATION
Explanation of Controls…………………………… . 22

Start-Up, Shut Down………………......…………....22

Main Burner Orifi ce Schedule…………….……….23
Gas Input Rate and Adjustments…………….. 23, 24

TROUBLESHOOTING GUIDE ..............................25-28

LED Indicator Troubleshooting .............................. 29

MAINTENANCE… ...................................................... 30

WARRANTY…............................................................31

IDENTIFICATION OF PARTS ................................32-33

UNIT NUMBER DESCRIPTION ................................. 35

START-UP INSPECTION SHEET ............................... 36

DESCRIPTION

The Power Vented Gas Fired Blower Unit Heaters are
factory assembled, high static pressure type, centrifugal
blower units designed for heavy duty applications such
as continuous operation or where a single unit heater
must do the entire heating job in a large area.These
blower type unit heaters may be used with the standard
adjustable louvers, with short duct runs or discharge

nozzles for spot heating. These blower type unit heaters
may be used where low sound levels are required. The
designs are certified by ETL as providing a minimum
of 83% thermal efficiency, and approved for use in
California. Do not alter these units in any way. If you
have any questions after reading this manual, contact
the manufacturer.

Figure 1 - Tubular Blower Unit Heater

See Identifi cation of Parts, Figures 12 through 18.

The following terms are used throughout this manual, in addition to the ETL requirements to bring attention to the
presence of potential hazards, or to important information concerning the product:

Indicates an imminently hazardous
situation which, if not avoided, will result in
death, serious injury, or substantial property
damage.

Indicates an imminently hazard­ous situation which, if not avoided, could result
in death, serious injury, or substantial property
damage.

situation which, if not avoided, may result in minor
injury or property damage.

NOTICE: Used to notify of special instructions on
installation, operation, or maintenance which are
important to equipment but not related to personal
injury.

2

Indicates an imminently hazardous

GENERAL SAFETY INFORMATION

Failure to comply with the general
safety information may result in extensive
property damage, severe personal injury, or

death.

This product must be installed by
a licensed plumber or gas fi tter when installed
within the Commonwealth of Massachusetts.

Installation must be made in accordance with local
codes, or in absence of local codes, with the latest
edition of the ANSI Standard Z223.1 (N.F.P.A. No. 54)
National Fuel Gas Code. All of the ANSI and NFPA

Standards referred to in these installation instructions
are those that were applicable at the time the design
of this appliance was certified. The ANSI Standards
are available from CSA Information Services, 1-800­463-6727. The NFPA Standards are available from the
National Fire Protection Association, Batterymarch Park,
Quincy, MA 02269. These unit heaters are designed for
use in airplane hangars when installed in accordance
with ANSI/NFPA No. 409, and in public garages when
installed in accordance with NFPA No. 88A and NFPA
No.88B.

If installed in Canada, the installation must conform with
local building codes, or in the absence of local building
codes, with CSA-B149.1 “Installation Codes for Natural
Gas Burning Appliances and Equipment” or CSA-B149.2
“Installation Codes for Propane Gas Burning Appliances
and Equipment.” These unit heaters have been designed
and certifi ed to comply with CSA 2.6. Also see sections
on installation in AIRCRAFT HANGARS and PUBLIC
GARAGES.

Do not alter the unit heater in any
way or damage to the unit and/or severe personal
injury or death may occur!

Disconnect all power and gas
supplies before installing or servicing the heater.
If the power disconnect is out of sight, lock
it in the open position and tag it to prevent
unexpected application of power. Failure to do
so could result in fatal electric shock, or severe

personal injury.

Do not attempt to convert the
heater for use with a fuel other than the one
intended. Such conversion is dangerous, as it
will create the risks previously listed.

Make certain that the power source conforms to the
electrical requirements of the heater.

Do not depend upon a thermostat
or other switch as sole means of disconnecting
power when installing or servicing heater.
Always disconnect power at main circuit breaker
as described above. Failure to do so could result
in fatal electric shock.

Special attention must be given to any grounding
information pertaining to this heater. To prevent the risk of
electrocution, the heater must be securely and adequately
grounded. This should be accomplished by connecting
a ground conductor between the service panel and the
heater. To ensure a proper ground, the grounding means
must be tested by a qualifi ed electrician.

Do not insert fi ngers or foreign objects into heater or its
air moving device. Do not block or tamper with the heater
in any manner while in operation, or just after it has been
turned off, as some parts may be hot enough to cause
injury.

This heater is intended for general heating applications
ONLY. It must NOT be used in potentially dangerous
locations such as fl ammable, explosive, chemical-laden,
or wet atmospheres.

In cases in which property damage may result from
malfunction of the heater, a back-up system or
temperature sensitive alarm should be used.

The open end of piping systems being
purged shall not discharge into areas where there
are sources of ignition or into confined spaces
UNLESS precautions are taken as follows: (1) by
ventilation of the space, (2) control of the purging
rate, (3) elimination of all hazardous conditions. All
precautions must be taken to perform this operation

in a safe manner!

Ensure that all power sources conform
to the requirements of the unit heater, or damage to
the unit will result!

Follow installation instructions CAREFULLY to avoid
creating unsafe conditions. All wiring should be done
and checked by a qualifi ed electrician, using copper wire
only. All gas connections should be made and leak-tested
by a suitably qualifi ed individual, per instructions in this
manual. Also follow procedures listed on “Gas Equipment
Start-Up Sheet” located in this manual.

Use only the fuel for which the heater is designed (see
rating plate). Using LP gas in a heater that requires
natural gas, or vice versa, will create risk of gas leaks,
carbon monoxide poisoning, and explosion.

Unless otherwise specifi ed, the following conversions
may be used for calculating SI unit measurements:
1 foot = 0.305 m
1 inch = 25.4 mm
1 gallon = 3.785 L
1 pound = 0.453 kg
1 psig = 6.894 kPa
1 cubic foot = 0.028m

1000 BTU/cu. ft. = 37.5 MJ/m
1000 BTU per hour = 0.293 kW
1 inch water column = 0.249 kPa
1 litre/second = CFM x 0.472
1 meter/second = FPM ÷ 196.8

3

3

3

Table 1 - Performance and Dimensional Data - Tubular Blower Unit Heater

Unit Size 100 125 150 175 200 250 300 350 400
PERFORMANCE DATA†

Input - BTU/Hr. 100,000 125,000 150,000 175,000 200,000 250,000 300,000 350,000 400,000
(kW) (29.3) (36.6) (44.0) (51.3) (58.6) (73.3) (87.9) (102.6) (117.2)
Output - BTU/Hr. 83,000 103,750 124,500 145,250 166,000 207,500 246,000 290,500 332,000
(kW) (24.3) (30.4) (36.5) (42.6) (48.6) (60.8) (72.1) (85.1) (97.3)
Thermal Effi ciency - % 83 83 83 83 83 83 82 83 83
Free Air Delivery - CFM 1,181 1,476 1,771 2,067 2,362 2,953 3,501 4,134 4,724
(cu. m/s) (0.557) (0.697) (0.836) (0.976) (1.115) (1.394) (1.652) (1.951) (2.230)
Air Temperature Rise - Deg. F 65 65 65 65 65 65 65 65 65
(Deg. C) (36) (36) (36) (36) (36) (36) (36) (36) (36)
Outlet Velocity - FPM 370 463 555 395.0 451.0 564.0 422 498 570
(m/s) (1.879) (2.351) (2.819) (2.006) (2.291) (2.864) (2.143) (2.529) (2.895)
Full Load Amps at 115V 7.3 9.4 9.4 14.2 14.2 15.6 15.6 20.8 20.8
Maximum Circuit Ampacity 8.6 11.2 11.2 17.1 17.1 18.9 18.9 25.4 25.4
MOTOR DATA: Motor HP 1/4 1/2 1/2 3/4 3/4 1 1 1-1/2 1-1/2
Motor kW 0.19 0.37 0.37 0.56 0.56 0.75 0.75 1.11 1.11
Motor Type ODP** SPH SPH SPH SPH SPH Cap. Start Cap. Start Cap. Start Cap. Start
RPM 1,725 1,725 1,725 1,725 1,725 1,725 1,725 1,725 1,725
Amps @ 115V 5.1 7.2 7.2 11.6 11.6 13.0 13.0 18.2 18.2
DIMENSIONAL DATA - inches (mm)
"A" Height to Top of Flue 33-3/4 33-3/4 33-3/4 33-3/4 33-3/4 33-3/4 34 34 34
(857) (857) (857) (857) (857) (857) (864) (864) (864)
"B" Jacket Width of Unit 20-3/4 20-3/4 20-3/4 32-3/4 32-3/4 32-3/4 50-3/4 50-3/4 50-3/4
(527) (527) (527) (832) (832) (832) (1289) (1289) (1289)
"C" Width to Centerline Flue 13-3/8 13-3/8 13-3/8 19-3/8 19-3/8 19-3/8 28-3/8 28-3/8 28-3/8
(340) (340) (340) (492) (492) (492) (721) (721) (721)
"D" Depth to Front Hanger 21 21 21 21 21 21 21 21 21
(533) (533) (533) (533) (533) (533) (533) (533) (533)
"E" Hanging Distance Width 18-5/8 18-5/8 18-5/8 30-5/8 30-5/8 30-5/8 48-5/8 48-5/8 48-5/8
(473) (473) (473) (778) (778) (778) (1235) (1235) (1235)
"F" Hanging Distance Depth 19 19-1/2 19-1/2 32-3/4 32-3/4 32-3/4 23-1/2 32-3/4 32-3/4
(483) (495) (495) (832) (832) (832) (597) (832) (832)
"G" Discharge Opening Width 18-3/4 18-3/4 18-3/4 30-3/4 30-3/4 30-3/4 48-3/4 48-3/4 48-3/4
(476) (476) (476) (781) (781) (781) (1238) (1238) (1238)
"H" Depth to Centerline Flue 4-3/4 4-3/4 4-3/4 4-3/4 4-3/4 4-3/4 5-1/8 5-1/8 5-1/8
(121) (121) (121) (121) (121) (121) (130) (130) (130)
"L" Discharge Opening Height 24-1/2 24-1/2 24-1/2 24-1/2 24-1/2 24-1/2 24-1/2 24-1/2 24-1/2
(622) (622) (622) (622) (622) (622) (622) (622) (622)
"M" Overall Unit Width 25-1/4 25-1/4 25-1/4 37-1/4 37-1/4 37-1/4 55-1/4 55-1/4 55-1/4
(641) (641) (641) (946) (946) (946) (1403) (1403) (1403)
"P" Overall Unit Depth 49-3/4 49-3/8 49-3/8 56-1/8 56-1/8 56-1/8 53-3/8 56-1/8 56-1/8
(1264) (1254) (1254) (1426) (1426) (1426) (1356) (1426) (1426)
*Flue Size Diameter - in 5 5 5 5 5 5 6 6 6
(mm) (127) (127) (127) (127) (127) (127) (152) (152) (152)
Blower Size - inches (Qty) 9 10 10 12 12 12 10 (2) 12 (2) 12 (2)
Gas Inlet, Natural Gas - in 1/2 1/2 1/2 1/2 1/2 3/4 3/4 3/4 3/4
Gas Inlet, LP Gas - in 1/2 1/2 1/2 1/2 1/2 1/2 OR 3/4 1/2 OR 3/4 1/2 OR 3/4 1/2 OR 3/4
Approximate Unit Weight - lb 171 175 202 245 264 289 370 390 429
(kg) (78) (79) (92) (111) (120) (131) (168) (177) (195)
Approximate Ship Weight - lb 256 261 289 381 400 425 520 547 595
(kg) (116) (118) (131) (173) (181) (193) (236) (248) (270)

† Ratings shown are for unit installations at elevations between 0 and 2,000 ft (0 to 610m). For unit installations in U.S.A. above 2,000 ft. (610m), the unit input must be fi eld derated 4%

for

each 1,000 ft. (305m) above sea level; refer to local codes, or in absence of local codes, refer to the latest edition of the National Fuel Gas Code, ANSI Standard Z223.1 (N.F.P.A. No. 54).

For installations in Canada, any reference to deration at altitudes in excess of 2,000 ft. (610m) are to be ignored. At altitudes of 2,000 ft. to 4,500 ft. (610 to 1372m), the unit must be

fi eld derated to 90% of the normal altitude rating, and be so marked in accordance with the ETL certifi cation. See Table 8A for fi eld deration information.

* Flue collar is factory supplied with unit; to be fi eld installed per included instructions.
** LEGEND: SPH = SPLIT PHASE CAP. START = CAPACITOR START ODP = OPEN DRIP PROOF

4

INSTALLATION

Figure 2 - Dimensional Drawing – Tubular Blower Unit Heater

1 1/8

D8931B

E

C

Electrical Control Panel

Rear View

Flue

H

F

Gas Valve

Do not install unit heaters in
corrosive or fl ammable atmospheres! Premature
failure of, or severe damage to the unit will
result!

Avoid locations where extreme
drafts can affect burner operation. Unit heaters
must not be installed in locations where air for
combustion would contain chlorinated, halo­genated or acidic vapors. If located in such an
environment, premature failure of the unit will
occur!

Since the unit is equipped with an automatic gas ignition
system, the unit heater must be installed such that the
gas ignition control system is not directly exposed to
water spray, rain or dripping water.

NOTICE: Location of unit heaters is related directly to
the selection of sizes. Basic rules are as follows:

MOUNTING HEIGHT: Unit Heaters equipped with

standard fan guards must be installed at a minimum
of 8' (2.4m) above the fl oor, measured to the bottom of
the unit. For mounting heights above 8', see Table 2 to
compare unit height to heat throw distance.

AIRCRAFT HANGARS: Unit Heaters must be installed
in aircraft hangars as follows: In aircraft hangars, unit
heaters must be at least 10' (3.0m) above the upper
surface of wings or engine enclosures of the highest
aircraft to be stored in the hangar, and 8' (2.4m) above
the floor in shops, offices and other sections of the
hangar where aircraft are not stored or housed. Refer
to current ANSI/NFPA No. 409, Aircraft Hangars. In
Canada, installation is suitable in aircraft hangars when
acceptable to the enforcing authorities.

32 1/2

D

P

Side View

M

B

G

(Discharge

Opening)

Front View

L

(Discharge

Opening)

D8931B

33

PUBLIC GARAGES: In repair garages, unit heaters must
be located at least 8' (2.4m) above the fl oor. Refer to the
latest edition of NFPA 88B, Repair Garages.

In Canada, installation must be in accordance to the
latest edition of CSA B149 “Installation Codes for Gas
Burning Appliances and Equipment.”

AIR DISTRIBUTION: Direct air towards areas of
maximum heat loss. When multiple heaters are involved,
circulation of air around the perimeter is recommended
where heated air fl ows along exposed walls. Satisfactory
results can also be obtained where multiple heaters are
located toward the center of the area with heated air
directed toward the outside walls. Be careful to avoid
all obstacles and obstructions which could impede the
warm air distribution patterns. Heat throw distances are
presented in Table 2.

Unit heaters should not be installed to maintain low
temperatures and/or freeze protection of buildings.
A minimum of 50°F (10°C) thermostat setting must
be maintained. If unit heaters are operated to maintain

lower than 50°F (10°C), hot flue gases are cooled
inside the heat exchanger to a point where water
vapor (a fl ue gas by-product) condenses onto the heat
exchanger walls. The result is a mildly corrosive acid that
prematurely corrodes the aluminized heat exchanger and
can actually drip water down from the unit heater onto
fl oor surface. Additional unit heaters should be installed
if a minimum 50°F (10°C) thermostat setting cannot be
maintained.

A

5

INSTALLATION (continued)

Table 2 - Heat Throw Data

Standard Heater 30° Nozzle 60° Nozzle 90° Nozzle

Degree

Nozzle

None 8 60 65 70 75 80 90 105 110 120

90°* 15 30 x 25 35 x 30 40 x 35 45 x 40 50 x 40 60 x 45 70 x 45 80 x 50 100 x 50

* It is not recommended to mount a unit with a 90 nozzle under 10 feet.
Notes: 1. All throw data fi gures are approximations. Allowances should be made for optimum performance, altitude, etc.

2. NR - Units not recommended at these mounting heights.

3. 30°, 60° and 90° nozzles are shipped unassembled.

Distance From

Floor to Bottom

of

of Unit "H" - ft

(m)

(2.4) (18.3) (19.8) (21.3) (22.9) (24.4) (27.4) (32.0) (33.5) (36.6)

10 54 56 60 64 68 78 90 95 100

(3.0) (16.5) (17.1) (18.3) (19.5) (20.7) (23.8) (27.4) (29.0) (30.5)

12 44 46 49 57 61 68 80 84 90

(3.7) (13.4) (14.0) (14.9) (17.4) (18.6) (20.7) (24.4) (25.6) (27.4)

15

(4.6) (13.7) (14.9) (15.8) (18.3) (21.3) (22.6) (24.4)

20

(6.1) (14.0) (16.5) (19.2) (20.1) (21.3)

30° 8 65 70 75 80 85 95 115 120 125

(2.4) (19.8) (21.3) (22.9) (24.4) (25.9) (29.0) (35.1) (36.6) (38.1)

10 57 60 64 68 72 86 99 105 110

(3.0) (17.4) (18.3) (19.5) (20.7) (21.9) (26.2) (30.2) (32.0) (33.5)

12 50 54 57 60 64 77 88 94 100

(3.7) (15.2) (16.5) (17.4) (18.3) (19.5) (23.5) (26.8) (28.7) (30.5)

15

(4.6) (13.7) (14.6) (15.2) (16.2) (19.5) (22.6) (24.1) (25.6)

20

(6.1) (13.4) (14.3) (17.7) (20.1) (21.6) (22.9)

60° 8 75 80 85 90 95 110 125 130 138

(2.4) (22.9) (24.4) (25.9) (27.4) (29.0) (33.5) (38.1) (39.6) (42.1)

10 65 70 75 79 83 95 109 115 120

(3.0) (19.8) (21.3) (22.9) (24.1) (25.3) (29.0) (33.2) (35.1) (36.6)

12 60 64 68 72 76 84 100 103 108

(3.7) (18.3) (19.5) (20.7) (21.9) (23.2) (25.6) (30.5) (31.4) (32.9)

15 50 54 56 61 65 71 85 88 94

(4.6) (15.2) (16.5) (17.1) (18.6) (19.8) (21.6) (25.9) (26.8) (28.7)

20

(6.1) (14.9) (15.8) (16.8) (18.0) (19.8) (23.5) (24.7) (25.9)

(4.6) (9.1) (7.6) (10.7) (9.1) (12.2) (10.7) (13.7) (12.2) (15.2) (12.2) (18.3) (13.7) (21.3) (13.7) (24.4) (15.2) (30.5) (15.2)

20

(6.1) (12.2) (10.7) (17.1) (12.2) (19.8) (12.2) (21.3) (13.7) (24.4) (13.7)

25

(7.6) (15.2) (10.7) (18.3) (10.7) (19.8) (12.2) (22.9) (12.2)

30

(9.1) (16.8) (10.7) (18.3) (10.7) (19.8) (12.2)

100,000 125,000 150,000 175,000 200,000 250,000 300,000 350,000 400,000

Approximate Distance of Heat Throw - Feet (Meters)

NR NR

NR NR NR NR

NR

NR NR NR

NR

NR NR NR NR

NR NR NR NR NR

NR NR NR NR NR NR

45 48 50 53 64 74 79 84

49 52 55 59 65 77 81 85

45 49 52 60 70 74 80

UNIT SIZE BTU/Hr

46 54 63 66 70

44 47 58 66 71 75

40 x 35 56 x 40 65 x 40 70 x 45 80 x 45

50 x 35 60 x 35 65 x 40 75 x 40

55 x 35 60 x 35 65 x 40

6

INSTALLATION (continued)

AIR FOR COMBUSTION: The unit heater shall be
installed in a location in which the facilities for
ventilation permit satisfactory combustion of gas,
proper venting, and the maintenance of ambient
temperature at safe limits under normal conditions of
use. The unit heater shall be located in such a manner

as not to interfere with proper circulation of air within the
confi ned space. When buildings are so tight that normal
infi ltration does not meet air requirements, outside air
shall be introduced per Sections 1.3.4.2 and 1.3.4.3 of
ANSI Z223.1 for combustion requirements. A permanent
opening or openings having a total free area of not less
than one square inch per 5,000 BTU/Hr (1.5 kW) of total
input rating of all appliances within the space shall be
provided.

NOTICE: Unit Heater sizing should be based on heat
loss calculations where the unit heater output equals
or exceeds heat loss.

CLEARANCES: Each Gas Unit Heater shall be

located with respect to building construction and other
equipment so as to permit access to the Unit Heater.
Clearance between vertical walls and the vertical sides
of the Unit Heater shall be no less than 6" (152mm).
To ensure access to the control box, a minimum of 18"
(457mm) is required for the control box side. A minimum
clearance of 6" (152mm) must be maintained between
the top of the Unit Heater and the ceiling. The bottom of
the Unit Heater must be no less than 12" (305mm) from
any combustible. The distance between rear of unit and
vertical wall should be no less than 18" to maintain inlet
air fl ow. The distance between the fl ue collector and any
combustible must be no less than 6" (152mm). Also see
AIR FOR COMBUSTION and VENTING sections.

Unit Heaters must be hung level
from side to side and from front to back, see Figure
3A and 3B. Failure to do so will result in poor
performance and/or premature failure of the unit.

Ensure that all hardware used in
the suspension of each unit heater is more than
adequate for the job. Failure to do so may result
in extensive property damage, severe personal
injury, or death!

Refer to Figures 3A and 3B for suspension of units.

Figure 3A - Heater Mounting*

D2788A

*All hanging hardware and wood is not included with the unit (To
be fi eld supplied).

Figure 3B - Heater Suspension

NOTICE: Increasing the clearance distances may
be necessary if there is a possibility of distortion or
discoloration of adjacent materials.

Make certain that the lifting
methods used to lift the heater and the method
of suspension used in the fi eld installation of the
heater are capable of uniformly supporting the
weight of the heater at all times. Failure to heed
this warning may result in property damage or
personal injury!

Make sure that the structure
to which the unit heater is to be mounted is
capable of safely supporting its weight. Under
no circumstances must the gas lines, the venting
system or the electrical conduit be used to
support the heater; or should any other objects
(i.e. ladder, person) lean against the heater gas
lines, venting system or the electrical conduit for
support. Failure to heed these warnings may result
in property damage, personal injury, or death.

D4804

7

INSTALLATION (continued)

GAS PIPING

To avoid damage or possible personal injury, do not connect gas piping to this unit
until a supply line pressure/leak test has been completed. Connecting the unit before completing the
pressure/leak test may damage the unit gas valve and result in a fi re hazard.

Do not rely on a shut-off valve to isolate the unit while conducting gas pressure/leak tests.
These valves may not be completely shut off, exposing the gas valve to excessive pressure and damage.

PIPE SIZING

To provide adequate gas pressure to the gas unit heater,
size the gas piping as follows:

by the same piping arrangement, the total cu. ft./hr.
input and length of pipe must be considered.

1. Find the cu. ft./hr. by using the following formula:

Cu. ft./hr. =

Input BTU/Hr.

1000

2. Refer to Table 3. Match “Length of Pipe in Feet”
with appropriate “Gas Input - Cu. Ft./Hr.” fi gure. This
fi gure can then be matched to the pipe size at the
top of the column.

Example:
It is determined that a 67 foot (20.4m) run of gas

pipe is required to connect a 200 MBTU gas unit
heater to a 1,000 BTU/cu ft. (0.29kW) natural gas
supply.

200,000 BTU/Hr
1,000 BTU/cu. ft.

= 200 Cu. ft./hr.

Using Table 3, a 1 inch pipe is needed.

NOTICE: If the gas unit heater is to be fi red with LP
gas, consult your local LP gas dealer for pipe size
information.

NOTICE: HEATER INSTALLATION FOR USE WITH
PROPANE (BOTTLED) GAS MUST BE MADE BY
A QUALIFIED L.P. GAS DEALER OR INSTALLER.
HE/SHE WILL INSURE THAT PROPER JOINT
COMPOUNDS ARE USED FOR MAKING PIPE
CONNECTIONS; THAT AIR IS PURGED FROM
LINES; THAT A THOROUGH TEST IS MADE FOR
LEAKS BEFORE OPERATING THE HEATER; AND
THAT IT IS PROPERLY CONNECTED TO THE
PROPANE GAS SUPPLY SYSTEM.

Before any connection is made to the existing line
supplying other gas appliances, contact the local gas

NOTE: See General Safety Information section for
English/Metric unit conversion factors.

company to make sure that the existing line is of adequate
size to handle the combined load.

NOTICE: If more than one unit heater is to be served

Table 3 - Gas Pipe Size

Maximum Capacity of Pipe in Cubic Feet of Gas per Hour (Cubic Meters per Hour) for Gas Pressures of 0.5 psig (3.5 kPa) or Less,
and a Pressure Drop of 0.5 Inch Water Column (124.4 Pa)
(Based on a 0.60 Specifi c Gravity Gas)
Nominal

Iron Internal Length of Pipe, Feet (meters)

Pipe Size

Dia. 10 20 30 40 50 60 70 80 90 100 125 150 175 200

in. in. (3.0) (6.1) (9.1) (12.2) (15.2) (18.3) (21.3) (24.4) (27.4) (30.5) (38.1) (45.7) (53.3) (61.0)
1/2 0.622 175 120 97 82 73 66 61 57 53 50 44 40 37 35

(4.96) (3.40) (2.75) (2.32) (2.07) (1.87) (1.73) (1.61) (1.50) (1.42) (1.25) (1.13) (1.05) (0.99)
3/4 0.824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
(10.2) (7.08) (5.66) (4.81) (4.28) (3.91) (3.54) (3.34) (3.11) (2.92) (2.63) (2.38) (2.18) (2.04)
1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
(19.3) (13.2) (10.6) (9.06) (8.07) (7.36) (6.80) (6.23) (5.80) (5.52) (4.96) (4.53) (4.11) (3.82)
1 1/4 1.380 1400 950 770 660 580 530 490 460 430 400 360 325 300 280
(39.6) (26.9) (21.8) (18.7) (16.4) (15.0) (13.9) (13.0) (12.2) (11.3) (10.2) (9.20) (8.50) (7.93)
1 1/2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
(59.5) (41.3) (33.4) (28.0) (25.5) (22.9) (21.2) (19.5) (18.4) (17.6) (15.6) (14.2) (13.0) (12.2)
2 2.067 3950 2750 2200 1900 1680 1520 1400 1300 1220 1150 1020 950 850 800
(112) (77.9) (62.3) (53.8) (47.6) (43.0) (39.6) (36.8) (34.5) (32.6) (28.9) (26.9) (24.1) (22.7)
2 1/2 2.469 6300 4350 3520 3000 2650 2400 2250 2050 1950 1850 1650 1500 1370 1280
(178) (123) (99.7) (85.0) (75.0) (68.0) (63.7) (58.0) (55.2) (52.4) (46.7) (42.5) (38.8) (36.2)
3 3.068 11000 7700 6250 5300 4750 4300 3900 3700 3450 3250 2950 2650 2450 2280
(311) (218) (177) (150) (135) (122) (110) (105) (97.7) (92.0) (83.5) (75.0) (69.4) (64.6)
4 4.026 23000 15800 12800 10900 9700 8800 8100 7500 7200 6700 6000 5500 5000 4600
(651) (447) (362) (309) (275) (249) (229) (212) (204) (190) (170) (156) (142) (130)

1. Determine the required Cu. Ft./Hr. by dividing the input by 1000. For SI/Metric measurements: Convert BTU/Hr. to kilowatts. Multiply the units

inputs (kW) by 0.0965 to determine Cu. Meters./Hr. 2. FOR NATURAL GAS: Select pipe size directly from the table. 3. FOR PROPANE GAS:
Multiply the Cu. Ft./Hr. value by 0.633; then, use the table. 4. Refer to the metric conversion factors listed in the General Safety section for SI Unit
measurement conversions.

8

INSTALLATION (continued)

D3631C

PIPE INSTALLATION

1. Install the gas piping in accordance with applicable
local codes.

2. Check gas supply pressure. Each unit heater must
be connected to a manifold pressure and a gas
supply capable of supplying its full rated capacity as
specifi ed in Table 4. A fi eld LP tank regulator must
be used to limit the supply pressure to a maximum
of 14" W.C. (3.5 kPa). All piping should be sized in
accordance with the latest edition of ANSI Standard
Z223.1 (NFPA54), National Fuel Gas Code; in
Canada, according to CSA B149. See Tables 1
& 3 for correct gas piping size. If gas pressure is
excessive on natural gas applications, install a
pressure regulating valve in the line upstream from
the main shutoff valve.

3. Adequately support the piping to prevent strain on
the gas manifold and controls.

4. To prevent the mixing of moisture with gas, run the
take-off piping from the top, or side, of the main.

5. Standard Unit Heaters, optional two-stage units are
supplied with a combination valve which includes:

a. Manual "A" valve
b. Manual "B" valve
c. Solenoid valve
d. Pressure regulator
Pipe directly into the combination valve (see Figure

4).

6. Gas valve has a pressure test post requiring a
3/32" hex head wrench to read gas supply and
manifold pressures. Open 1/4 turn counterclockwise
to read, turn clockwise to close and reseat. A 5/16"
ID hose fi ts the pressure post.

7. Provide a drip leg in the gas piping near the gas
unit heater. A ground joint union and a manual gas
shutoff valve should be installed ahead of the unit
heater controls to permit servicing. The manual
shutoff valve must be located external to the jacket
(See Figure 4).

8. Make certain that all connections have been
adequately doped and tightened.

Do not over tighten the inlet gas
piping into the valve. This may cause stresses that
will crack the valve!

NOTICE: Use pipe joint sealant resistant to the
action of liquefied petroleum gases regardless of
gas conducted.

Figure 4 - Pipe Installation, Standard Controls

D3631C

Never use an open fl ame to detect
gas leaks. Explosive conditions may exist which
may result in personal injury or death!

The appliance and its individual shutoff valve must be
disconnected from the gas supply piping system during
any pressure testing of that system in excess of 1/2 psig
(3.5 kPa).

The appliance must be isolated from the gas supply
piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less than
1/2 psig (3.5 kPa).

Table 4 - Gas Piping Requirements

SINGLE STAGE GAS PIPING REQUIREMENTS*

GasType Natural Gas Propane (LP) Gas

Manifold 3.5 in. W.C. 10.0 in. W.C.

Pressure (0.9 kPa) (2.5 kPa)

14.0 in. W.C. Max. 14.0 in. W.C. Max.

Supply Inlet (3.5 kPa) (3.5 kPa)
Pressure

(1.2 kPa) (2.7 kPa)

*For single stage application only at normal altitudes.

5.0 in. W.C. Min. 11.0 in W.C. Min.

Check all pipe joints for leakage
using a soap solution or other approved method.
Never use an open flame or severe personal
injury or death may occur!

9

BLOWER SET UP AND ADJUSTMENT

BLOWER SET UP

BLOWER DRIVE ADJUSTMENT

The drive ratio of the motor and blower sheaves has
been preset at the factory for a temperature rise of 65°F
at .2" W.C. If the unit is to be operated under different
static air fl ow or pressure requirements, the drive ratio
must be altered by means of the adjustable sheave on

belt without fi rst disconnecting all electrical
power to the unit or severe personal injury may
result!

Never attempt to adjust the drive

the blower motor.

1. Ensure that all packing material, support blocks, etc.
have been removed from the unit.

2. Adjust the blower drive belt tension by means of the
two tension bolts on the blower motor base. When
proper tension has been achieved, the mid-point
defl ection of the belt will be 3/4" when subjected to a
5 lb. force.

3. Recheck all electrical connections.

4. When power is applied, ensure that the motor and
blower are rotating in a counter clockwise direction
when viewed from the drive side.

1. Remove the belt guard and loosen the belt tension
bolts on the blower motor base.

2. Loosen the set screw on the adjustable half of the
motor sheave. To increase the blower speed, turn
the adjustable half of the sheave clockwise, counter
clockwise to slow the blower. Retighten the set
screw.

3. Realign the blower and motor sheaves if necessary.

4. Adjust the belt tension as specifi ed in the BLOWER
SET UP section under step 2.

5. Replace the belt guard.

5. Measure the current draw of the motor.

Never operate the unit without

The "at speed" current draw of the

motor must never exceed that specified on the

the belt guard in place or severe personal injury

may result!
motor rating plate or severe damage to the motor
will result!

6. Check that the air flow of the unit, the rpm
and current draw of the blower motor and the
temperature rise are within the limits specified in
Table 1, the blower motor rating plate and the rating
plate on the unit, respectively (also see Motor Data
on page 11).

Figure 5 - Motor & Blower Assembly *

* PART DESCRIPTION
A. Blower Housing and Wheel
C. Blower Shaft
D. Bearings
E. Drive Pulley
F. Driven Pulley
G. V-Belt
H. Blower Motor
I. Blower Housing Support (LH)
H. Blower Housing Support (RH)

Never operate the unit beyond
the specified limits or severe damage to, and or
premature failure of, the unit will result!

D9000

* NOTICE: THE BLOWER ASSEMBLY FOR THE 100/250 UNITS
CONSISTS OF 1 WHEEL, 1 HOUSING, 1 SHAFT AND 2 BEARINGS.
FOR 300/400 UNITS THE BLOWER ASSEMBLY CONSISTS OF 2
WHEELS, 2 HOUSINGS, 1 SHAFT AND 3 BEARINGS.

10

MOTOR AND PULLEY

All motor data based on standard ODP Motors.

Table 5

Motor Full Load Amps*

VOLTAGE - PHASE

HP 115-1 208-1 230-1 208-3 230-3 460-3 575-3
1/4 5.1 2.2 2.3 1.7 1.3 0.7 N/A
1/2 7.2 3.7 3.8 2.3 2.2 1.1 0.8
3/4 11.6 5.2 5.0 3.0 3.4 1.7 1.1

1 13.0 6.6 6.5 3.4 3.4 1.7 1.3

1-1/2 18.2 9.1 9.1 5.1 5.2 2.6 1.7

2 21.0 11.3 10.5 6.2 6.0 3.0 N/A

* Average value, all speeds and frequencies.

Table 6

Pulley Table 1725 RPM Motors (1/3 to 2 H.P.)

MOTOR PULLEYS

BLOWER PULLEYS

IVL34

1.9-2.9

Turns Open

5
4-1/2
4
3-1/2
3
2-1/2
2
1-1/2
1
1/2
0

IVL44

2.8-3.8

5
4-1/2
4
3-1/2
3
2-1/2
2
1-1/2
1
1/2
0

AK51

4.7

697
734
771
807
844
880
918
954

991
1027
1064
1101
1137
1174
1211
1247
1284
1321
1357
1394

AK56

5.2

630
663
697
730
763
796
829
863
896
928
962

995
1028
1061
1094
1127
1161
1194
1227
1260

AL64

6.0

546
575
603
633
661
690
719
748
776
805
834
863
891
920
949

978
1006
1035
1064
1093

AL74

7.0

468
493
517
542
567
591
616
641
665
690
715
739
764
789
813
838
863
887
912
936

AL84

8.0

410
431
453
474
496
517
539
560
582
604
625
647
668
690
712
733
755
776
798
819

AL104

10.0

327
345
362
380
397
414
431
448
466
483
500
518
535
552
569
587
604
621
638
656

11