Cambridge Engineering S Series User manual

S-TM7-02-18
S400-S3200 REV. F
S-SERIES
DIRECT GAS-FIRED
INDUSTRIAL BLOW-THRU® SPACE HEATER
TECHNICAL MANUAL
mWARNING:
Improper installation, adjustment, alteration, service or maintenance can cause property dam-
age, injury or death. Read the installation, operating, and maintenance instructions thoroughly
before installing or servicing this equipment.
FOR YOUR SAFETY
The use and storage of gasoline or other flammable vapors and liquids in open containers in
the vicinity of this appliance is hazardous.
FOR YOUR SAFETY
If you smell gas:
1. Open windows.
2. Don’t touch electrical switches.
3. Extinguish any open flame.
4. Immediately call your gas supplier.
®
90.1
ASHRAE
ASHRAE
COMPLIANT
COMPLIANT
Made in the USA ®

LIMITED WARRANTY
Cambridge Engineering's Limited Warranty is included within the Terms and Conditions that are sent
with every Order Acknowledgement. For questions regarding Limited Warranty, contact Cambridge
Engineering's Customer Service Group at 1-800-473-4569.

S-SERIES
BLOW-THRU®SPACE HEATER
TECHNICAL MANUAL
Cambridge Engineering, Inc.
760 Long Road Crossing Dr.
Chesterfield, MO. 63005
Phone: [phone]
Fax: [phone]
www.cambridge-eng.com
Copyright 2018
Cambridge Engineering, Inc.
All Rights Reserved
Contents
Hazard Summary ..............................................................................................................2
Typical System Overview .................................................................................................3
Accessory Identication..................................................................................................3
Heater Operation.............................................................................................................4
Heater Conguration.......................................................................................................4
Installation Instructions.....................................................................................................5
Uncrating Instructions.....................................................................................................5
Mounting Location..........................................................................................................5
Roof Top Mounting - Curb / Stand / Rail .......................................................................6
Roof Top / Thru Wall Mounting - Stand / Rail ...............................................................7
Under Roof Mounting - Curb .........................................................................................7
Roof Top Mounting.........................................................................................................8
Thru Wall Mounting......................................................................................................10
Roof Top / Thru Wall Mounting ...................................................................................12
Under Roof Mounting...................................................................................................14
Vertical Indoor Mounting..............................................................................................16
Vertical Outdoor Mounting ...........................................................................................18
Rain Hood Inlet Skirt ...................................................................................................20
Unit Inlet Skirt ..............................................................................................................21
Gas Piping.....................................................................................................................22
Electrical Wiring ..........................................................................................................23
Start-Up Instructions.......................................................................................................24
Calibration Procedures ...................................................................................................29
Operating Instructions.....................................................................................................32
Operating Sequence ......................................................................................................32
Electronic Thermostat ...................................................................................................33
TSS Controller .............................................................................................................35
Maintenance Instructions................................................................................................44
Troubleshooting Instructions ..........................................................................................48
Troubleshooting Guide..................................................................................................48
Damper Motor Replacement & Adjustment .................................................................54
Reference ........................................................................................................................56
Electrical Control Enclosure Isometric Drawing..........................................................56
Electrical Wiring Diagrams ..........................................................................................57
Electrical Connection Diagram ....................................................................................62
Gas Train Drawings ......................................................................................................63
Individual Component Descriptions .............................................................................67
ANSI/ASHRAE/IESNA Standard 90.1 ........................................................................73

Cambridge Engineering, Inc. 2 S-Series Technical Manual
HAZARD SUMMARY
Hazard Identification
Warnings and Cautions appear at appropriate sections throughout this manual. Read these carefully.
mWARNING: Indicates a potentially hazardous situation which could result in
death or serious injury.
mCAUTION: Indicates a potentially hazardous situation which may result in
minor or moderate injury. It may also be used to alert against
unsafe practices.
CAUTION: Indicates a situation that may result in accidents with equipment or
property damage only.
The following safety precautions apply to the instal-
lation, operation, and maintenance of the equipment
described by this technical manual.
mWARNING:
Any unauthorized modification of this equipment
shall void the warranty.
mWARNING:
Only qualified personnel should attempt instal-
lation, service, and repair of this equipment. Use
extreme caution and observe safety regulations at
all times.
mWARNING:
Recirculation of room air is not permitted.
Adequate building relief must be provided so as to not
over pressurize the building when the heating system
is operating at its rated capacity. It should be noted
that this can be accomplished by taking into account,
through standard engineering methods, the structure’s
designed infiltration rate, by providing properly sized
relief openings, or by interlocking a powered exhaust
system, or by a combination of these methods.
If the failure or malfunction of this heater creates a
hazard to other fuel burning equipment in the build-
ing, (e.g. when the heater is providing the make-up air
to a boiler room), the unit is to be interlocked to open
inlet air dampers or other such devices.
If the heater is installed such that an inlet duct is
utilized, the duct system must be purged with at least
four air changes prior to an ignition attempt.
Installation in Aircraft Hangars
Refer to the Standard for Aircraft Hangars,
ANSI/NFPA 409, for specific information on the
installation requirements for these heaters in air-
craft hangars.
Installation in Parking Garages
Refer to the Standard for Parking Structures, ANSI/
NFPA 88A, or the Standard for Repair Garages,
ANSI/NFPA 88B, for specific information on the
installation requirements for these heaters in public
garages.
Installation in Car Wash Facilities
A non-recirculating, S-Series Space Heater used in a
Car Wash tunnel application may be designated as a
T-Series Heater on the nameplate.
This S-Series Technical Manual also applies to all
T-Series Heaters.
IMPORTANT
If in doubt regarding installation application, con-
tact Cambridge Customer Service Group at 1-800-
473-4569 during the hours of 8:00 a.m. to 5:00 p.m.
Central Time, Monday through Friday.

S-Series Technical Manual 3 Cambridge Engineering, Inc.
TYPICAL SYSTEM OVERVIEW
ACCESSORY IDENTIFICATION
Roof Top Mounting
RH-RT
MDD
DT
UNIT
MC
MR
AMS
DD
DE
Indoor Vertical Mounting
DT
DE
DT
IE
RH-TW
ISR
UNIT
Thru Wall Mounting
MDD
RH-TW
ISR
DT
DE
UNITFS
AMS Adjustable Mounting Stand
DD Discharge Duct
DE Directional Elbows
DT Downturn
FS Filter Section
ID Inlet Duct
IE Inlet Elbow
IP Inlet Plenum
ISR Inlet Skirt-Rain Hood
ISU Inlet Skirt-Unit
MC Mounting Curb
MDD Motorized Discharge Damper
MR Mounting Rail
RH-RT Rain Hood-Roof Top
RH-TW Rain Hood-Thru Wall
Component Identification
RH-RT MDD
UNIT
MR
AMS
DE
DT
WALL SLEEVE
(BY OTHERS)
Roof Top / Thru Wall Mounting
Under Roof Mounting
IE UNIT
DE
DT
MDD
IP
MC
ID
Outdoor Vertical Mounting
ISU
DE
DT
WALL SLEEVE
(BY OTHERS)
DT
UNIT
MDD

Cambridge Engineering, Inc. 4 S-Series Technical Manual
HEATER CONFIGURATION
PORT FOR MEASURING
MANIFOLD PRESSURE
MODULATING GAS VALVE
SAFETY SHUT-OFF VALVE
HIGH LIMIT
LEAK TEST PORT
DISCHARGE TEMPERATURE SENSOR
DISCHARGE AIR TEMPERATURE
DAMPER BLADES
DAMPER MOTOR
ELECTRICAL CONTROL
ENCLOSURE
SHUT-OFF VALVE
SAMPLING BOX
HINGED ACCESS DOOR
REGULATOR
MANUAL SHUT-OFF VALVEBURNER VIEWPORT
BURNER ASSEMBLY
IGNITER & FLAMEROD
Cambridge S-Series Blow-Thru®heaters are utilized
to meet the space heating requirements of commercial
or industrial buildings. The control system is typically
designed to cycle the heaters on and off in response to
the rise and fall of the space temperature. The heater
will discharge air at the temperature selected (up to
160ºF). The operating thermostat is typically located
near the perimeter of the building in a location which
is out of the direct path of the heated discharge air,
insulated from cold surfaces, and shielded from cold
drafts created by air infiltrating the building.
TYPICAL SYSTEM OVERVIEW
HEATER OPERATION

S-Series Technical Manual 5 Cambridge Engineering, Inc.
1. Verify that the number of items on the Bill of
Lading matches the number of items received.
2. Check for shipping damage. Take photographs of
any damage.
IMPORTANT
If damage is found, immediately file a claim with the
carrier before proceeding further.
3. Check the items received to make sure they agree
with the ordering information including verification
of data on the unit nameplate.
IMPORTANT
Do not discard any components or accessories.
MOUNTING LOCATION
Verify feasibility of the installation location selected
with respect to accessibility to the heater for service
and maintenance functions. Ensure the positioning of
the heater does not inhibit fork truck operation, stor-
age rack locations, or other operations within the facil-
ity. Ensure the heater inlet and outlet are not blocked
or severely restricted in any way that would affect the
rated airflow through the heater or affect the desired
air distribution pattern of the heater.
It is the responsibility of the installer to communicate
any potential problems with the installation to the per-
son or persons responsible for providing the installa-
tion instructions or drawings prior to proceeding with
the installation.
IMPORTANT
Where the mounting height of the heater is a con-
sideration, work platforms or service lifts should be
provided for accessibility to the equipment for ser-
vice and maintenance activities.
IMPORTANT
Field constructed intake accessories should be de-
signed to minimize the entry of snow and rain.
IMPORTANT
The minimum clearance from the face of the elec-
trical control enclosure to surrounding grounded
surfaces for service activities is 42". Adequate clear-
ance of 42" for burner removal is also required.
Access for service functions is also required on the
side of the unit opposite the control enclosure for a
distance of 24".
INSTALLATION INSTRUCTIONS
UNCRATING INSTRUCTIONS

Cambridge Engineering, Inc. 6 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
ROOF TOP MOUNTING - CURB / STAND / RAIL
MOUNTING STAND
MOUNTING RAIL
DOWNTURN / CURB
WITH FLASHING
ROOF INSULATION
2 X 6 TREATED LUMBER B
A
C
24"
TYP.
REF.
24"
4
5
3
2
1
CURB SECTION
INSULATION
2.5"1 5/8"
2 x 2 WOOD NAILER
(PROVIDED)
FLASHING
Model A B C
S400/S800 65½" 33¼" 25 3/8"
S950/S1200/S1600 78 5/8" 33¼" 42"
S1850/S2200/S3200 90¼" 36¼" 47 1/8"
STAND DETAIL NOTES
1
TREATED TIMBER AS REQUIRED UNDER MOUNTING
CURB, RAIL AND STAND TO SECURE AND LEVEL UNIT.
2
SECURE MOUNTING STAND TO TIMBER WITH WOOD LAG
SCREWS AS SHOWN.
3
SECOND MOUNTING ASSEMBLY IS REQUIRED ONLY ON
UNITS WITH FILTER SECTIONS.
4
MOUNTING STAND CONSTRUCTION:
12 GA. GALVANIZED STEEL
5
MOUNTING RAIL CONSTRUCTION:
18 GA. GALVANIZED STEEL
6
REMOVE HANGER BRACKET AND REPLACE SCREWS
7
ADJUSTABLE ± 3¾"
6
(BY OTHERS)
2 x 6 TREATED LUMBER
7 10½"

S-Series Technical Manual 7 Cambridge Engineering, Inc.
INSTALLATION INSTRUCTIONS
ROOF TOP / THRU WALL MOUNTING - STAND / RAIL
Model A B C
S400/S800 57 7/8" 33¼" 25 3/8"
S950/S1200/S1600 69 7/8" 33¼" 42"
S1850/S2200/S3200 75¾" 36¾ " 47 1/8"
UNDER ROOF MOUNTING - CURB
MOUNTING STAND
MOUNTING RAIL
ROOF INSULATION
2 X 6 TREATED LUMBER B
A
C
24"
TYP.
4
5
3
2
1
STAND DETAIL NOTES
1
TREATED TIMBER AS REQUIRED UNDER MOUNTING RAIL
AND STAND TO SECURE AND LEVEL UNIT.
2
SECURE MOUNTING STAND TO TIMBER WITH WOOD LAG
SCREWS AS SHOWN.
3THIRD MOUNTING ASSEMBLY IS REQUIRED ONLY ON
UNITS WITH FILTER SECTIONS.
4
MOUNTING STAND CONSTRUCTION:
12 GA. GALVANIZED STEEL
5
MOUNTING RAIL CONSTRUCTION:
18 GA. GALVANIZED STEEL
6
REMOVE HANGER BRACKET AND REPLACE SCREWS
7
STAND IS ADJUSTABLE ±3¾"
CURB
ROOF INSULATION
REF.
24"
CURB SECTION
INSULATION
2.5" 1 5/8"
2 x 2 WOOD NAILER
(PROVIDED)
6
(BY OTHERS)
2 x 6 TREATED LUMBER
7 10½"

Cambridge Engineering, Inc. 8 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
ROOF TOP MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer and the roof manufacturer before install-
ing this equipment.
IMPORTANT
Before proceeding with the installation, verify the
feasibility of the location selected with respect to
accessibility for service and maintenance functions.
IMPORTANT
To minimize snow and rain ingestion, position the
heater inlet opposite the prevailing winds.
mCAUTION
To prevent contaminated air from being drawn
into the heater, install the heater’s inlet at least
10 feet from any building exhaust, process ex-
haust, sewer stacks, or other sources that would
allow contaminants to be drawn into the heater.
Consult local codes for additional references.
1. Prepare roof penetration to the dimensions below.
See page 6 for Roof Top Mounting - Curb/Stand/
Rail drawing.
IMPORTANT
Accurate measurements are critical and will affect
the installation process. Verify that the roof opening
aligns with the curb opening.
2. Secure the mounting curb and mounting rail(s) per
the structural engineer and roof manufacturer’s rec-
ommendations.
IMPORTANT
The roof curb and mounting rail(s) should be
installed so that the heater will mount level.
Cambridge recommends mounting the heater a mini-
mum of 24" off the roof surface in areas where snow
accumulation could impact heater operations.
3. Attach the mounting stands to the heater while the
heater is on the ground. Adjust the height of the
stands so the heater inlet is slightly (1/8” below
level) lower than the discharge. This allows any
ingested moisture to drain out of the heater, through
weep holes located at the inlet of the heater, onto
the roof surface.
4. Lower the discharge duct through the mounting
curb and the roof opening and secure the counter-
flashing to the mounting curb.
5. Use a crane or comparable lifting device to raise
and position the equipment. Use a spreader bar to
prevent damage and connect slings to the lifting
brackets.
mWARNING:
Do not attach lifting means to heater accessories.
Make connections to heater only.
IMPORTANT
Inlet accessories may be attached on the ground or
on the roof depending on the method chosen by the
installer.
6. Caulk all the joints between the heater and the
accessories with silicone caulk to prevent water
leaks.
IMPORTANT
Do not caulk the downturn/counterflashing for the
curb interface.
7. Seal all roof penetrations to prevent roof leaks.
8. Install the directional elbows. Consult the job lay-
out for the orientation of the elbows.
Weight
Roof Opening*
Model L W
S400/S800 550 lbs. 13" 24¾"
S950/S1200/S1600 800 lbs. 15" 41½"
S1850/S2200/S3200 1500 lbs. 24¼" 46½"
* Dimensions allow for ¾" clearance on each side

S-Series Technical Manual 9 Cambridge Engineering, Inc.
CURB / RAIL / STAND DETAIL
RAIN HOOD
ADJUSTABLE MOUNTING STAND
DO NOT CAULK
THIS JOINT
EXTERNAL GAS TRAIN WITH ENCLOSURE
ELECTRICAL JUNCTION BOX
(APPLICABLE TO SOME FM AND XL GAPS OPTIONS)
FM: FACTORY MUTUAL
XL GAPS: FORMERLY IRI (INDUSTRIAL RISK INSURERS)
NOTE:
ELECTRICAL CONTROL ENCLOSURE
(PROVIDED WITH EXTERNAL GAS TRAIN)
MOUNTING RAIL
FILTER SECTION
UNIT
DOWNTURN
(OPTIONAL)
COUNTERFLASHING
MOUNTING CURB
DISCHARGE DUCT
DIRECTIONAL
ELBOWS
TYPICAL INSTALLATION
ROOF TOP MOUNTING
10½"
12"
2 X 4 TREATED LUMBER
(PROVIDED)
2 X 6 TREATED LUMBER
(BY OTHERS)
TREATED LUMBER
(BY OTHERS)
ROOF
TREATED LUMBER
(BY OTHERS) OPENING
24"
TREATED LUMBER (THICKNESS OF ROOF INSULATION) AS
REQUIRED UNDER MOUNTING STANDS AND CURB TO SECURE
AND LEVEL THE UNIT AND TO SPREAD THE LOAD. (BY OTHERS)

Cambridge Engineering, Inc. 10 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
THRU WALL MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer before installing this equipment.
IMPORTANT
Before proceeding with the installation, verify the
feasibility of the location selected with respect to
accessibility to the equipment for service and main-
tenance functions.
mCAUTION
To prevent contaminated air from being drawn into
the heater, install the heater’s inlet at least 10 feet
from any building exhaust, process exhaust, sewer
stacks, or other sources that would allow contami-
nants to be drawn into the heater. Consult local
codes for additional references.
1. Prepare wall penetration to the dimensions below.
2. Connect inlet accessories to the unit including
filter section (optional) and rain hood prior to lift-
ing the heater in place. Note the inlet skirt for rain
hood (optional) is installed from the outside of the
building (page 20).
3. Install hanging rods to adequate ceiling supports
and align with the hanging brackets on the unit.
Refer to hanging rod size shown on table below.
Locate the hanging rods so that the weep holes
provided in the rain hood are located a minimum
of 3" beyond the outside wall surface.
4. Remove the lag bolts used to fasten the unit to the
skid. Do not remove the hanging brackets from the
side of the heater. On S400/S800 model heaters,
rotate the mounting brackets 180˚ and retighten
the securing hardware.
5. Use a forklift or comparable lifting device to raise
and position the heater. Take precautions to pre-
vent equipment damage (dents and/or scratches)
when the heater is being lifted into position.
6. Use washers and double lock nuts to secure the
unit on the hanging rods.
IMPORTANT
The discharge end of the heater should be raised
slightly (1/8" above level). This allows any ingested
moisture to drain out of the heater through weep
holes located in the rain hood to the exterior of the
building.
7. Apply shims, by others, at the bottom of the rain
hood to take up slack in the opening, leaving a
small joint between the top of the rain hood and
the wall.
8. Install fiberglass insulation in the gaps around the
wall opening and the rain hood. Apply enough
material to accommodate the full thickness of the
wall.
9. Install finish trim pieces (by others) to the top,
sides and bottom of the rain hood on both the
inside and outside wall surfaces.
10. Apply silicone caulk at the joint between the top
of the rain hood and the outside wall surface.
Make certain this is a continuous bead and that it
runs the entire width of the rain hood. Caulk all
other exposed joints.
11. Install the directional elbows. Consult the job lay-
out for the orientation of the elbows.
Weight
Hanging Rods Wall Opening**
Model Qty. Size A B* C H W
S400/S800 550 lbs. 4 (6*) 3/8" dia. 57 7/8" 33¼" 27 7/8" 26" 25½"
S950/S1200/S1600 800 lbs. 4 (6*) 3/8" dia. 69 7/8" 33¼" 43 7/8" 29" 42¼"
S1850/S2200/S3200 1500 lbs. 4 (6*) 1/2" dia. 75¾" 36¾" 48 7/8" 38¾" 47¼"
*For optional lter section
** Dimensions allow for 1" clearance on each side

S-Series Technical Manual 11 Cambridge Engineering, Inc.
TYPICAL INSTALLATION
THRU WALL MOUNTING
RAINHOOD
ELECTRICAL CONTROL ENCLOSURE
HANGING ROD
HANGING BRACKET
INTERIOR WALL TRIM
(BY OTHERS)
(BY OTHERS)
DOWNTURN
UNIT
ELBOWS
DIRECTIONAL
REMOTE CONTROL STATION
SEDIMENT TRAP
HIGH PRESSURE REGULATOR (HPR)
HIGH PRESSURE SHUT-OFF VALVE
HIGH PRESSURE SUPPLY TAP
LOW PRESSURE SHUT-OFF VALVE
(OPTIONAL)
(BY OTHERS)
CONTROL WIRING CONDUIT
(BY OTHERS)
VENT PIPE TO OUTDOORS
(LOCATE MIN. 10 FT. FROM INTAKE)
VENT w/SCREEN
INCOMING POWER
(BY OTHERS)
EXTERIOR WALL TRIM
INLET GAS PIPE
(BY OTHERS)
(OPTIONAL)
FILTER SECTION
HANGING ROD DETAILHANGING BRACKET DETAIL
HANGING ROD
WASHER
WASHER
NUT
DOUBLE LOCK NUTS
DOUBLE LOCK NUTS
SHIPPING POSITION
NUT
WASHER
WASHER
HANGING ROD
L BRACKET
FOR S400 - S800 UNITS
C BRACKET
FOR S950 - S3200 UNITS
HANGING RODS, NUTS AND WASHERS BY OTHERS

Cambridge Engineering, Inc. 12 S-Series Technical Manual
Weight
Wall Opening*
Model H W
S400/S800 550 lbs. 16" 28¼"
S950/S1200/S1600 800 lbs. 18" 45"
S1850/S2200/S3200 1500 lbs. 27½" 50"
INSTALLATION INSTRUCTIONS
ROOF TOP / THRU WALL MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer and the roof manufacturer before install-
ing this equipment.
IMPORTANT
Before proceeding with the installation, verify the fea-
sibility of the location selected with respect to acces-
sibility to the equipment for service and maintenance
functions.
IMPORTANT
To minimize snow and rain ingestion, position the
heater inlet opposite the prevailing winds.
mCAUTION
To prevent contaminated air from being drawn
into the heater, install the heater’s inlet at least 10
feet from any building exhaust, process exhaust,
sewer stacks, or other sources that would allow
contaminants to be drawn into the heater. Consult
local codes for additional references.
1. Prepare wall penetration to the dimensions below.
See page 7 for Roof Top/Thru Wall Mounting
Stand/Rail drawing.
IMPORTANT
Accurate measurements are critical and will affect
installation process.
2. Secure the mounting rails per the structural engi-
neer and roof manufacturer’s recommendations.
IMPORTANT
The mounting rails should be installed so that the
heater will mount level. Cambridge recommends
mounting the heater a minimum of 24" off the roof
surface in areas where snow accumulation could
impact heater operations
3. Attach the mounting stands to the heater while
the heater is on the ground. Adjust the height
of the stands so the heater inlet is slightly (1/8”
below level) lower than the discharge. This allows
any ingested moisture to drain out of the heater,
through weep holes located at the inlet of the
heater, onto the roof surface.
4. Use a crane or comparable lifting device to raise
and position equipment. Use a spreader bar to
prevent damage and connect slings to the lifting
brackets.
mWARNING:
Do not attach lifting means to heater accessories.
Make connections to heater only.
IMPORTANT
Inlet accessories may be attached on the ground or
on the roof depending on the method chosen by the
installer.
5. Install the wall sleeve to the heater discharge.
6. Install fiberglass insulation in gaps around the
wall opening and wall sleeve. Apply enough mate-
rial to accommodate the full thickness of the wall.
7. Install finish trim pieces (by others) to top, sides
and bottom of the wall sleeve on both the inside
and outside wall surfaces.
8. Apply silicone caulk at the joint between the top
of the wall sleeve and the outside wall surface.
Make certain this is a continuous bead and that it
runs the entire width of the wall sleeve. Caulk all
other exposed joints.
9. Seal all roof penetrations to prevent roof leaks.
10. Install the downturn and directional elbows.
Consult the job layout for the orientation of the
elbows.
* Dimensions allow for 1½" clearance on each side

S-Series Technical Manual 13 Cambridge Engineering, Inc.
STAND DETAIL
RAIN HOOD
ADJUSTABLE MOUNTING STAND
EXTERNAL GAS TRAIN WITH ENCLOSURE
ELECTRICAL JUNCTION BOX
(APPLICABLE TO SOME FM AND XL GAPS OPTIONS)
ELECTRICAL CONTROL ENCLOSURE
(PROVIDED WITH EXTERNAL GAS TRAIN)
MOUNTING RAIL
FILTER SECTION
UNIT
DOWNTURN
(OPTIONAL)
ELBOWS
DIRECTIONAL
INTERIOR WALL TRIM
(BY OTHERS)
WALL SLEEVE
(BY OTHERS)
EXTERIOR WALL TRIM
TYPICAL INSTALLATION
ROOF TOP / THRU WALL MOUNTING
10½"
12"
2 X 4 TREATED LUMBER
(PROVIDED)
2 X 6 TREATED LUMBER
(BY OTHERS)
TREATED LUMBER
(BY OTHERS)

Cambridge Engineering, Inc. 14 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
UNDER ROOF MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer and the roof manufacturer before install-
ing this equipment.
IMPORTANT
Before proceeding with the installation, verify the
feasibility of the location selected with respect to
accessibility to the equipment for service and main-
tenance functions.
m CAUTION
To prevent contaminated air from being drawn
into the heater, install the heater’s inlet at least 10
feet from any building exhaust, process exhaust,
sewer stacks, or other sources that would allow
contaminants to be drawn into the heater. Consult
local codes for additional references.
1. Prepare roof penetration to the dimensions below.
See page 7 for Under Roof Mounting - Curb
drawing
IMPORTANT
Accurate measurements are critical and will affect
the installation process. Verify that the roof opening
aligns with the curb opening.
2. Install the mounting curb and the mounting struc-
ture per the structural engineer and roof manufac-
turer’s recommendations.
IMPORTANT
The mounting curb or mounting structure should
be installed such that the heater’s inlet plenum will
mount level.
3. Seal all roof penetrations to prevent roof leaks.
4. Lower the inlet duct through the mounting curb
and the roof opening.
5. Secure the inlet plenum to the curb.
6. Connect inlet accessories to the heater including
filter section (optional) and inlet elbow prior to
lifting the heater in place.
7. Install hanging rods to adequate ceiling supports
and align with the hanging brackets on the heater.
Refer to hanging rod size shown on table below.
8. Remove the lag bolts used to fasten the unit to the
skid. Do not remove the hanging brackets from the
side of the heater. On S400/S800 model heaters,
rotate the hanging brackets 180˚, and retighten the
securing hardware.
9. Use a forklift or comparable lifting device to raise
and position the heater. Take precautions to pre-
vent equipment damage (dents and/or scratches)
when the heater is being lifted into position.
10. Use washers and double lock nuts to secure equip-
ment on the hanging rods.
11. Install the directional elbows. Consult the job lay-
out for the orientation of the elbows.
Weight
Hanging Rods Roof Opening**
Model Qty. Size A B* C L W
S400/S800 550 lbs. 4 (6*) 3/8" dia. 57 7/8" 33¼" 27 7/8" 25" 25"
S950/S1200/S1600 800 lbs. 4 (6*) 3/8" dia. 69 7/8" 33¼" 43 7/8" 30" 41¼"
S1850/S2200/S3200 1500 lbs. 4 (6*) 1/2" dia. 75¾" 36¾" 48 7/8" 37¼" 46¾"
*For optional lter section
** Dimensions allow for ¾" clearance on each side

S-Series Technical Manual 15 Cambridge Engineering, Inc.
CURB DETAIL
FILTER SECTION (OPTIONAL)
TREATED LUMBER (THICKNESS OF ROOF INSULATION) AS
REQUIRED UNDER MOUNTING CURB TO SECURE AND LEVEL
THE UNIT AND TO SPREAD THE LOAD. (BY OTHERS)
TYPICAL INSTALLATION
UNDER ROOF MOUNTING
HANGING ROD DETAILHANGING BRACKET DETAIL
HANGING ROD
WASHER
WASHER
NUT
DOUBLE LOCK NUTS
DOUBLE LOCK NUTS
SHIPPING POSITION
NUT
WASHER
WASHER
HANGING ROD
L BRACKET
FOR S400 - S800 UNITS
C BRACKET
FOR S950 - S3200 UNITS
HANGING RODS, NUTS AND WASHERS BY OTHERS

Cambridge Engineering, Inc. 16 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
VERTICAL INDOOR MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer before installing this equipment.
IMPORTANT
Before proceeding with the installation, verify the
feasibility of the location selected with respect to
accessibility to the equipment for service and main-
tenance functions.
m CAUTION
To prevent contaminated air from being drawn
into the heater, install the heater’s inlet at least 10
feet from any building exhaust, process exhaust,
sewer stacks, or other sources that would allow
contaminants to be drawn into the heater. Consult
local codes for additional references.
1. Prepare wall penetration to the dimensions below.
2. Connect the inlet accessories to the heater including
the filter section (optional), the inlet elbow and the
rain hood prior to standing the heater upright. Note
the inlet skirt for the rain hood (optional) is installed
from the outside of the building (page 20).
3. Install hanging rods to adequate ceiling and/or wall
supports per the structural engineer’s recommenda-
tions and align with the hanging brackets on the
heater. Refer to the hanging rod size shown on the
table below. Locate the hanging rods so that the
weep holes provided in the rain hood are located a
minimum of 3" beyond the outside wall surface.
4. Remove the lag bolts used to fasten the unit to the
skid. Rotate the hanging brackets for the vertical
application and retighten the securing hardware.
5. Utilizing the lifting brackets on the front of the heater,
use a forklift or comparable lifting device to raise
and position the heater. Take precautions to prevent
equipment damage (dents and/or scratches) when the
heater is being lifted into position.
6. Use washers and double lock nuts to secure equip-
ment on hanging rods.
IMPORTANT
The rain hood should be sloped slightly (1/8" off
level). This allows any ingested moisture to drain
out of the heater through weep holes located in the
rain hood to the exterior of the building.
7. Apply shims at the bottom of the rain hood to take up
slack in the opening, leaving a minimal joint between
the top of the rain hood and the wall.
8. Install fiberglass insulation in the gaps around the
wall opening and the rain hood. Apply enough mate-
rial to accommodate the full thickness of the wall.
9. Install finish trim pieces (by others) to the top, sides
and bottom of the rain hood on both the inside and
outside wall surfaces.
10. Apply silicone caulk at the joint between the top
of the rain hood and the outside wall surface.
Make certain this is a continuous bead and that it
runs the entire width of the rain hood. Caulk all
other exposed joints.
11. Install the second downturn and directional
elbows. Consult the job layout for the orientation
of the elbows.
Weight
Hanging Rods Wall Opening*
Model Qty. Size A B H W
S400/S800 650 lbs. 4 3/8" dia. 23 3/8" 27 7/8" 26" 25½"
S950/S1200/S1600 950 lbs. 4 3/8" dia. 26" 43 7/8" 29" 42¼"
S1850/S2200/S3200 1750 lbs. 4 1/2" dia. 34 7/8" 48 7/8" 38¾" 47¼"
* Dimensions allow for 1" clearance on each side

S-Series Technical Manual 17 Cambridge Engineering, Inc.
TYPICAL VERTICAL INDOOR INSTALLATION
INLET ELBOW
RAIN HOOD
FILTER SECTION
DOWNTURN
SECOND DOWNTURN
(OPTIONAL)
DIRECTIONAL
ELBOWS
HANGING ROD
(BY OTHERS)
INTERIOR WALL TRIM
KNEE BRACE
(BY OTHERS)
(BY OTHERS)
STRUCTURAL
ELECTRICAL CONTROL
ENCLOSURE
GAS TRAIN WIRING
(FIELD CONNECTED)
(OPTIONAL)
GAS TRAIN
(BY OTHERS)
EXTERIOR WALL TRIM
UNIT
BASE OF HEATER
mWARNING:
The primary structural support
element of a vertically mounted
heater is the base. Any support to
the heater cabinet should be con-
sidered secondary, only as a means
to help stabilize the heater.
HANGING BRACKET DETAIL
L BRACKET
FOR S400 - S800 UNITS
C BRACKET
FOR S950 - S3200 UNITS
HANGING RODS, NUTS AND WASHERS BY OTHERS
HANGING ROD DETAIL
DOWNTURN
SECOND DOWNTURN
(OPTIONAL)
MOUNTING POSITION
SHIPPING POSITION
DOUBLE LOCK NUTS
NUT
WASHER
WASHER
HANGING ROD
MOUNTING POSITION
SHIPPING POSITION
HANGING ROD
WASHER
WASHER
NUT
DOUBLE LOCK NUTS

Cambridge Engineering, Inc. 18 S-Series Technical Manual
INSTALLATION INSTRUCTIONS
VERTICAL OUTDOOR MOUNTING
mWARNING:
Due to the size and weight of this equipment, it
is recommended the heater mounting structure be
reviewed and approved by a qualified structural
engineer before installing this equipment.
IMPORTANT
Before proceeding with the installation, verify the
feasibility of the location selected with respect to
accessibility to the equipment for service and main-
tenance functions.
mCAUTION
To prevent contaminated air from being drawn
into the heater, install the heater’s inlet at least 10
feet from any building exhaust, process exhaust,
sewer stacks, or other sources that would allow
contaminants to be drawn into the heater. Consult
local codes for additional references.
1. Prepare wall penetration to the dimensions below.
2. Connect the inlet accessories to the heater includ-
ing the filter section (optional).
3. Install structural uprights and associated wall sup-
ports per structural engineers recommendations.
4. Remove the lag bolts used to fasten the unit to the
skid.
5. Utilizing the lifting brackets on the front of the
heater, use a forklift or comparable lifting device
to raise and position the heater. Take precau-
tions to prevent equipment damage (dents and/
or scratches) when the heater is being lifted into
position.
6. Secure the heater in place with contractor supplied
hardware.
7. Install the wall sleeve to the downturn.
8. Install fiberglass insulation in the gaps around the
wall opening and the wall sleeve. Apply enough
material to accommodate the full thickness of the
wall.
9. Install finish trim pieces (by others) to the top,
sides and bottom of the wall sleeve on both the
inside and outside wall surfaces.
10. Apply silicone caulk at the joint between the wall
sleeve and the outside wall surface. Make certain
this is a continuous bead and that it runs the entire
width of the wall sleeve. Caulk all other exposed
joints.
11. Mount the gas train enclosure to the wall structure
and connect gas piping between the heater and the
enclosure.
12. Install the inlet skirt to the heater inlet and attach
the skirt extension to the exterior wall (page 21).
13. Install wall sleeve, second downturn and direc-
tional elbows. Consult the job layout for the orien-
tation of the elbows.
Weight
Mounting Holes Wall Opening*
Model A B C H W
S400/S800 500 lbs. 57 7/8" 33¼" 27 7/8" 16" 25¼"
S950/S1200/S1600 750 lbs. 69 7/8" 33¼" 43 7/8" 18" 42½"
S1850/S2200/S3200 1500 lbs. 75¾" 36¾" 48 7/8" 27½" 47¾"
* Dimensions allow for 1½" clearance on each side