Trane GRAA Owner's manual

^
AF
Installation
GRAA-IOM-1
Operation
Maintenance
Library
Service
Literature
P roduct
Sec t
ion
Air
Handling
Product
Make - Up
Air
Model
GRAA ,
GRBA ,
GRCA ,
GRDA
Literature T
ype
I
nstallation ,
Operation ,
Maintenance
Sequence
^
Date
January
1995
File No.
SV - AH -
MUA -
GRAA - IOM -
1 - 1
95
Supersedes
Ne
w
Rooftop
Gas
Heating ,
Cooling
and
Ventilating
Unit
Sizes
100
MBh -
1200
MBh
" A "
Design
Sequence
Since
the
Trans
Company has
a policy of
continuous product
improvement, it
reserves
the right to
change
specifications
and
design without
notice.
The installation
and servicing
of the
equipment referred
to in this
booklet
should be
done
by
qualified,
experienced
technicians.
OAmerican
Standard
Company
1995

General
Information
Literature
Chang
e
History
GRAA
- IOM
- 1 (January
1995
)
Original
issue
of manual
describes
installation
of GRAA,
GRBA,
GRCA,
GRDA
Rooftop
Gas
Heating,
Cooling
and
Ventilating
Units,
for A
Design.
Warnings
and
Cautions
Notice
that
WARNINGS
and
CAUTIONS
appear at
appropriate
intervals
throughout
this
manual.
Warnings
alert
installer,
owner,
operator
or service
personnel
to
potential
hazards
that could
result
in
personal
injury
or
death.
Cautions
are provided
to alert
personnel
to
conditions
which
could
result
in
damage
to the
equipment
or
cause
property
damage.
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.
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 .
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.
WARNING:
Improper
installation,
adjustment,
alteration,
service
or
maintenance
can
cause property
damage,
injury
or
death.
Read
the
installation,
operating
and
maintenance
instructions
thoroughly
before
installing
or
servicing
this
equipment.
Warnings
Approved
for use
in California
when
equipped
with
spark
ignition
.
Installer
Please
Note:
This
equipment
has
been
test fired
and
inspected
. It
has been
shipped
free
from
defects
from
our
factory .
However
, during
shipment
and
instal
l ation
,
problems such
as loose
wires,
leaks or
loose
fasteners
may
occur.
It is the
installer
' s
responsibility
to inspect
and
correct
any
problems
th
a t may be
found
.
Install,
operate and
maintain
unit in
accordance
with
manufacturer's
instructions
to avoid
exposure
to
.,
fiP
P
R
OYED
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.

Model
Number Description
(All furnaces)
DIGIT
1 - Gas
Heating
Equipment
G =
G as
DIGIT 2 - Unit
Type
F = Rooftop D uct
Furnace
R = R
oofto p
H
eating
U
ni t
S
= Special
U ni t T y p
e
DIGIT
3 - Furnace
Type
A
= S t a ndard
T e m p
R
ise (
20 -6 0 D eg. F )
LH
B = S tandard
Te m p R ise ( 2
0-
60
Deg .
F )
RH
C = High
Temp Rise (60-90
Deg. F)
LH
D
= High
Tem p R is e
(60-90 De
g.
F ) RH
E = B lank F
urnac e S
l
ee v e
LH
G
= Blank
Furnace
Sleeve RH
S
= Special
Furnace
Type
DIGIT
4
-
Development
Sequence
A
= F irs t G
eneratio n
DIGIT 5,6
-
Input
Capacity
Single Furnace
10 =
100
MBh Input 30 =
300 MBh
Input
15 = 150
MBh Input 35 =
350 MBh
Input
20 = 200
MBh
Input 40 =
400 MBh
Input
25 =
250
MBh x
Double Furnace
50 = 500
MBh Input 70 =
700 MBh
Input
60 = 600
MBh Input
80 =
800
MBh Input
Triple Furnace
12 = 1200
MBh Input
SS
=Special
unit
DIGIT
7 - Venting
Type
G = G ravi t y V e n
ting
P = P ower
Ventin g
S = S pecial
V enting
DIGIT 9
- Gas
Control Option
(Intermittent Pilot Ignition)
A = Single-Stage
B = Two-Stage
C
= Hydraulic
Modulating (60-100)
D = Hydraulic
Modulating
(75-200)
E
= Hydraulic
Modulating W/Bypass and
limit
(60-100)
F = Hydraulic
Modulating W/Bypass
(75-200)
G = Electronic
Modulating W/Room T-Stat
H = Electronic
Modulating W/Duct T-Stat
J = Electronic
Modulating
W/Duct T-Stat
and
Override Room
Thermostat
K=
Electronic Modulating
W/External 4-20
mA Input (Furnace 1)
L = Electronic
Modulating W/External 4-20
mA
Input
M=
Electronic
Modulating W/External 0-10
VDC Input
(Furnace 1)
N
= Electronic
modulating
W/External 0-10
VDC
Input
P =
VAV Control Two-Stage
R=
VAV Control Three-Stage
T =
VAV Control Four-Stage
U =
S-350 2 Stage Modular Electronic
Control
System
W =
S-350 3
Stage Modular Electronic
Control System
X =
S-350 4 Stage
Modular Electronic
Control System
Y = S-350 6
Stage Modular Electronic
Control
System
S
=Special Gas
Control
DIGIT
13
- Heat
Exchanger Material
1
= Aluminized
S teel
2
= # 409
St ainless
S
teel ( F
i r s
t
Furn
a
ce
Only)
3 = #409 Stainless
Steel (All
Furnace
Sections)
4 = # 3 21 S
t a
inless
S t e el ( F irst
F
ur n ac e
O nly)
5 = #3 21 St ainless
S teel
( A ll
F ur na
ce
Sections)
6
= # 4 09
S tainless
S
teel
P
ackag
e ( F ir s t
Furnace Only)
7 = #409 S tainless
St
eel
P
acka
ge (
A
ll
F urnace S ections)
8
= #32 1 S tainless
S
teel P acka
g
e( F
irs t
Furnace
Only)
9 = #321
Stainless
Steel P acka g e(
A
ll
F urnace S ec t ions)
S
= Special
Heat Exchanger P ackage
DIGIT
14
- Rooftop
Arrangements
(Des i gnator
A -
L Assumes Furnace
S
ecti
on )
A
= D uct
Furnace
B
= B lower ( S
tandard)
C
= Blower
(Standard) Plenum
D
= B lower (Standard)
E vaporative
C
oole r
E
= Blower
(Standard) E vaporativ e
C ooler/Plenum
G =Blower (High CFM)
J = B lower
( H
igh C
F M
)/Plenum
K = B lower
(
H igh C F M )/ C oolin g
L = B lower
( H
igh C
F
M )/ C oo lin
g
/ P le n u m
S =
S
pecial R oofto p
A
rr a ng m ent
DIGIT 8
- Main
Power Supply
A =
115/60/1 E =230/60/3
B =
208/60/1
F =
460/60/3
C =
230/60/1 G =
575/60/3
D =
208/60/3 S = Special
Main
Power
Supply
DIGIT
10
-
Design
Sequence
A =
F irst D esi gn
DIGIT
11
-Design
Sequence
0=
F irst
D
esign
DIGIT
12
-
Fuel
Type
N
=
N atural
Ga
s
P =
LP G as (
P ropane)
L =
N a
t
ural G as
with 1 00% L
ockout
S
=
S pecial
F uel
type
DIGIT 15
= Roo fto p
H
eati
ng Un
i
t
Motor
Selection
0 = N one
(Rooftop duct furnace)
A = 1/2 HP w/contactor
B =
3/4 HP
w/contactor
C = 1
HP w/contactor
D = 1 1/2 HP
w/contactor
E = 2 HP w/contactor
F = 3
HP w/contactor
G =
5 HP
w/contactor
H = 1/2 HP w/magnetic starter
J = 3/4 HP w/magnetic
starter
K = 1 HP
w/magnetic
starter
L = 1 1/2 HP
w/magnetic starter
N =
2
HP w/magnetic starter
P =
3
HP w/magnetic starter
Q = 5
HP
w/magnetic
starter
R = 7
1/2
HP
w/magnetic starter
T = 10 HP
w/magnetic starter
U = 15
HP w/magnetic starter
S = Special
Motor
1a

DIGIT 16 = Motor
Speed
0 = N o
Selection
1 = Single
Speed ODP 1 800
RPM
2 = Single
Speed T EF C 180 0 R PM
3
=Single S peed H
igh E
fficiency ODP
1800 RPM
4 = S ingle
S p eed H
igh E fficie n c y
TEFC
1800 RPM
5 = 2S1
W ODP
1800/900 RPM
6 = 2S2W
ODP 1800/1200
RPM
7 = Special
M o t o
r Spee d & S
tarter
DIGIT 17 =
Coil
Options
0 = N o
cooling coil
selection
A = DX
coil, 4 R ow,
Single C
ircuit
B =
DX coil, 4 R
ow, D ual C
ircui
t
C =
DX coil, 6 R ow, S
ingle
Circuit
D = DX coil, 6 R
ow, D ual C
ircuit
E = Chilled
W ater C
oil, 4 R ow,
G = Chilled
Wa t
er Co il, 6 R
ow,
S = Special
coil
DIGIT 18
= Air
Inlet
Configuration
0 = N one ( R
ooftop
duct
furnace)
1 = Outside
Air( OA )
2 = Outside
A ir W /
A ir H ood
3 = R etur n
Air( R A)
4 = Outside
An d R
eturn A ir (
OA / RA )
5 = Outside
and R e t
urn Air W / A
ir H ood
S = Special A
ir inlet
configu r a t io n
DIGIT 19
= Air
Control & Damper
Arrangement
0 = N one (
R ooftop duct
f urnace)
A = O u t side
Air 2 pos. M otor/ SR
B = R eturn
Air 2 pos. Mo tor/
SR
C =
OA / RA 2 p os S
R
D =
OA / RA M o
d
M i r . W / M
ixe d A ir
C on t
rol/ M in. P o t
E = O
A/ R A M od
M tr W / M ixe d A
ir
Control/Min Pot/SR
G = OA
/
RA
M od
Mi r
W
/
M
ixed A ir Co ntr o l
H =
O A / RA
Mod Mtr
W/Mixed Air Control/ SR
J =
O A/
RA M od M tr W / M i n
P o
t
K =
OA/RA Mod
Mtr W/Min
P
ot/SR
L = O A /
RA
M
od Mtr w
/ D
ry
B ulb/ M ixe d A
ir
C o
n trol/ M in P ot
M = O
A/ RA M od
M tr w/ D
ry
B
ulb/ M ixe d A ir
C
ontrol/ M in
P ot/S R
N = OA
/
R
A M od
Mi r
w/ E nthalpy Co n
trolled
E conomizer/ SR
P = OA
/
RA
M o d M tr W / S p
ac e P re ss ur e
Controller
R =
OA / RA M od
M tr W / S -35 0 P
Proportional
Mixed
Air Control/SR
T =
OA
/
RA
M tr.
W /External
0- 10 VDC a
nd
4 - 20 mAAn
alog Inpu t
/( Ex tern a l In pu t)
U =
OA / RA
M tr. W /Exter na l
0 - 10 VDC a n d
4 -
2
0
m A A
nalog I npu t / SR (
Exte rnal I npu t )
W = A
shrae C ycle
I ( OA / RA 2 p os,
w/warm-u p stat/ SR
X =
Ashrae C
ycle I I ( OA / RA M
o d
W / W
arm-up S ta t/ M
ixe
d A ir/min
pot/S R
Y =
Ashrae
C ycle 111( O
A/RA M o d .
W/Warm-up
St at/ M ixed
Air/ SR
Z = M anual
D ampe
r
s
S = S pecial
air control a n d dam p
er
a r r ange m e
n
t
DIGIT 20
0 = N o n - C ali fo rnia
S hi pm ent
1 = California
Shipment
DIGIT 21 = Miscellaneous
Options
A = O rifice s
For E lev at io n A bov e 2 000 F
e et
( S pe c i f y E
l
e v a
ti
o n)
B = 1 2" E va p
or
a
tive M ed i a
C = M ois t ure
E limin at ors
D = H ori zonta l R
eturn
E = I nterlock
R elay -2 4V C
oil DPD T 1 0 A
F = Fr e e ze s t at
G = Fa n
T i m e D elay C on tr
ol ( D uc
t
F urnac e
Only)
H =
R etu r n A
ir Fir
e
sta
t
J= Supply Air
Firestat
K = M anual B lower S
wi
t
ch
L = 4 09 S
tainle ss S teel Furnace
D rip Pa n
N = F oil
F ace I
nsulation
P = Lo w Le ak
Da mpers
Q
= C logg ed
Filter S witch
R = H ig h /L ow
G as P ress u re L i m i t S
wi
t
c h e s
T = St a t us
Indicat o r La m ps (
E lec cab ine t )
V = Manu al Res et H
i gh
L imi t
Sw i tc h
W =Interl o ck Re lay -
2 4/ 1 15 V Co il
SPDT
10A
X = I nt e rloc k R
elay - 24 /1 1 5- 2 3
0V
Co
il
DPDT 1 0A
lb

Model Number
Description
(Air
Handling Units)
D I GIT 1 ,
2
- U
nit
T y p e
A H =
Air
Handling U
nit
DIGIT 3
-
Furnace
Type
0 = N one
DIGIT 4
- De
v
elopment
Sequence
A = F irst G
eneration
DIGIT 5 , 6 -
Unit Size
20
=
1500
-
8000 C fm
4
0 =
400 - 14000 Cf m
DIGIT 7
-
Vent i ng
Type
0 = N one
DIGIT 8 - Main
Power
Supply
A =
115/60/1
E =230/60/3
B = 208/60/1
F =460/60/3
C =
230/60/1 G =
575/60/3
D = 208/60/3
S = Special
Main
Power
Supply
D I
GIT
9 - Gas
Control Option
0 = N o
gas con t rol
optio n
DIGIT 9 - Gas
ConTrol
Option
(Intermittent Pilot Ign i
tion) (Cont . )
P = VAV C
ontrol Two- St
age
R = VA V Con t
rol T hree-Stage
T =
VAV Control F
our-Stage
U = S -350 2
S t age
Modular E lectronic
Control System
W = S -350 3
Stage M
odular E lectronic
C ontrol System
X = S-350 4
Stage M o d ular
E lectronic
Control
System
Y =
S-350 6
Stage M odular
E lectronic
Control System
S = Special
Gas C
ontrol
D I
GIT 10 - Design
Sequence
A = Firs t D
esign
DIGIT 11
- Design
Sequence
0 = First
Design
DIGIT 12
- Fuel
Type
0 =
No selection
DIGIT 13
-
Heat
Exchanger M
aterial
0 =
No selection
DIGIT 14
- Air
Handler
Arrangements
B = Blower
(Standard)
C = Blower
(Standard)
Plenum
D = Blower
(Standard)
Evaporative
Cooler
E = Blower
(Standard)
Evaporative
Cooler/Plenum
G
=Blower (High
CFM)
J
=Blower (High
CFM)/Plenum
K
=Blower (High
CFM)/Cooling
L =Blower
(High
CFM)/Cooling/Plenum
S
=Special Rooftop
Arrangment
DIGIT 15 = Motor
Selection
A = 1/2
HP w/contactor
B =
3/4
HP w/contactor
C = 1
HP w/contactor
D =
1
1/2 HP
w/contactor
E = 2 HP
w/contactor
F = 3
HP w/contactor
G =
5 HP w/contactor
H =
1/2
HP
w/magnetic starter
J =
3/4
HP w/magnetic
starter
K = 1 HP
w/magnetic starter
L = 1 1/2
HP w/magnetic
starter
N = 2 HP
w/magnetic starter
P = 3 HP
w/magnetic starter
Q = 5 HP
w/magnetic starter
R = 7 1/2 HP
w/magnetic starter
T = 10 HP
w/magnetic starter
U = 15
HP w/magnetic starter
S = Special
Motor
DIGIT 16 =
Motor
Speed & Starter
0 = N o
Selection
1 = S ingle S peed
O D P 1800 RP M
2 = Single
Speed T EF C
1 800 RPM
3 = Single
Speed High Efficiency
O DP
1800 RP M
4 = S ingle
S peed
High
E
fficiency
TEF C 1800 R P M
5 = 2 S1 W O D P 1
800/900 R P M
6 =
2S2W ODP
1800/1200 RP M
7 = Special
Motor
Speed & Starter
DIGIT 17 = Co l l
Options
0 = N
o co o ling coil
selection
A =
DX coil, 4 R ow,
Single C ircuit
B =
DX coil, 4 R ow,
D ual C ircuit
C = DX
coil, 6 R ow,
Single C ircuit
D = DX coil, 6 R ow, D
ual Circui t
E = C hilled
Water Coil, 4 R ow, S
ingle C ircuit
G = C hilled
Water C oil, 6 R ow,
D ual C ircuit
S = Special
coil
D IGIT 18 = Air
Inlet
Configuration
1 = Outside
Air(OA)
2 = Outside
Air W/Air Hood
3 = Return
Air(RA)
4 = Outside
And
Return Air
(OA/RA)
5 = Outside
and
Return Air W/Air Hood
S = Special
Air
inlet configuration
DIGIT 19 = Air
Control &
Damper
Arrangement
0 = N
o S election
A
= Outside
Air 2 pos. Mo t
or/S R
B = R eturn
Air 2 p os. M otor/S R
C =
OA/ RA 2 pos S R
D =
OA/ RA
M
o d Mtr.
W/
M
ixed Air
C ontrol/ M in. P ot
E =
OA/ RA Mod M t
r W/Mixed A ir
C
ontrol/Min P
ot/
SR
G =
O A/ RA M od M ir
W/Mixed Air C ontrol
H = OA/R A M od M
tr W/Mixe d
Air C ontroVS R
J =
O A/ R A M od
M tr W/ M in P o t
K =
OA/ R A M od M
tr W/ M in
P
ot/ SR
L =
O A/R A M o d
Mtr W/D
ry
B ulb/ M
ixed Air
Co n
tr ol/ M in P ot
M =
OA/
R A M od M tr W/ D
ry
B ulb/ M
ixed A ir
C ontrol/ M in P ot/ SR
N = O A/ R A M od Mtr W/ E nthalpy
C ontrolled E conomi z er/ SR
P =
O A/ R A
M od M t r W / S pace P
ressure
Controller
R = OA/ R A M od M tr
W/
S-350
P
P roportional M ixed A ir C ontrol/ SR
T =
OA/R
A M tr. W/External 0 -10 VDC
and
4-20mAAnalog
I n p ut/(External
Inpu t )
U = O A/ RA M t r . W/ E
xternal
0-10 VDC
an d
4 - 2 0
m
A Analog Inpu
t/ SR (
E xternal I npu t )
W =
Ashrae C ycle I( O
A/
RA 2 pos.
w/warm-up
stat/ SR
X = Ashrae C ycle I I (OA/ RA M o d
W/Warm-u p Stat/ M ixed Air/min
p ot/ SR
Y = Ashrae Cycle III(OA/ R A Mod.
W/Warm-up Stat/ M ixed Air/S R
Z
= M anual
D ampers
S = Special air control and damper
arrangement
DIGIT 20
- California
Sh i pment
0
= N on- C alifornia
Shipment
1 = C alifornia
Shipmen
t
DIGIT 21
= Miscellaneous
Options
A =
O rifices
F
or E levation A bove 2000
(Specify E levation)
B = 12" Evaporative M edia
C =
Mois t ure
E liminators
D =
Horizontal
R
eturn
E =
Interlock
R elay -2 4 V C oil DPDT 1
F =
Freezestat
G =
Fan
T ime D elay C ontrol ( D uc t
F ur
Only)
H = Return
Air Firestat
J= Supply
Air Firestat
K = Manual
Blower Switch
Feet
OA
ace
L = 409
Stainless Steel Furnace Drip
Pan
N
=Foil Face Insulation
P =Low Leak Dampers
Q =Clogged Filter Switch
R =High/Low
Gas Pressure Limit
Switches
T =Status
Indicator Lamps (Elec
cabinet)
V =
Manual
Reset High Limit
Switch
W =Interlock Relay
-24/115V Coil SPDT
10A
X= Interlock
Relay
-24/115-230V Coil
DPDT 10A
1c

TABLE
OF
CONTENTS
1 .
RECEIVING &
PRE -
INSTALLATION
INSTRUCTIONS
Access Panel Removal
...:................ 3
Rigging ........ .... ................3
Combustion Air Considerations
.............. 3
Location .....................
.......3
Mounting
/
Locations
..................... 3
II .
GENERAL REQUIREMENTS ............. 3
III .
INSTALLATION
Installation Clearances ....................
5
Mounting on Field Furnished
Supports ........ 5
Mounting on Roof Curb ...................
6
Venting ...............:................6
Duct Connections.......
...........
...
6
Gas
Piping
...........................6
Modulating
Gas
Control .. ..............
.
8
'Electrical Connections ... ............... 9
DX Coil Equipped Units
..................
10
Chilled Water Coil Equipped Units .......... 11
Evaporative Cooling Equipped Units ......... 11
IV . OPERATION
General Information
.....................
11
Gas Control System
..... ........
.
.....
11
Optional Gas Controls ... ' .............. 12
Air Handling
Requirements
and A
djustments
. .
12
Lighting
........... ........... 13
Gas Input Adjustment....
.............. 14
Pilot
Adjustment
........................
14
Primary Air
Shutter Adjustment ............. 14
Controls
..............................14
V . START
UP ...........
............... 15
VI
.
MAINTENANCE
......! ...............
16
VII .
TROUBLESHOOTING
................ 19
VII
I.
REP L ACEMENT
PARTS
.............. 24
IX .
SERVICE
NOTE
..... ............. 24
X .
START UP SHEET
....................
25
The following
terms are used
throughout this manual
to
bring attention to the presence of
potential
hazards or to
important information
concerning
the
product:
CAUTION: Indicates an
imminently
hazardous
situa-
tion
which,
if
not avoided, may result
in
minor
injury
or property damage.
NOTE: Used to notify of
special instructions on instal-
lation,
operation or
maintenance which are
important
to
equipment but not
related
to personal
injury haz-
ards.
1 .
RECEIVING INSTRUCTIONS
Inspect
shipment immediately when
received to deter-
mine
if any damage has
occurred to the
crate during
ship-
ment.
After
the
unit has been
uncrated, check for any
visible
damage to
the
unit. Check motor position
and turn blower
wheel to determine if damage has occurred to
these criti-
cal parts.
If
any damage is found,
the
cosignee
should sign the bill
of lading indicating such damage and
immediately file
claim for damage with
transportation
company.
PRE - INSTALLATION INSTRUCTIONS
W
he
n the u
nit
i
s
received and
uncrated,
check
the exter-
nal data plate and
all
labels
on the
unit for
type of gas,
electrica
l , and operational specifications to confir
m
tha
t
t hese agree with those
at
point
o
f installation. If the unit is
equipped with
an
Outdoor Duct Furnace, also check the
d
ata plate and all labels located inside each furnace.
Every
rooftop unit
will
include
an
informational
packet
which
will include the following: The blower manual, out-
door duct furnace and evaporative cooler/cooling coil
manuals (if applicable
to
the
unit order),
wiring
diagram(s),
and
special controls/data sheets.
ACCESS PANEL REMOVAL
Each access panel is held in place with two "grip" latches.
To remove an access panel:
use a slotted head screw dri-
ver to turn the latch
screwhead counter clockwise. Using
the handle provided, push
the
panel upwards.
Pull the bot-
tom of the
panel out and lower the panel to disengage
it
from
the top
lip.
To replace
an
access door
panel, guide
-2-

the
panel door
upwards on
the
tracks, and push
up
into
the
top
lip, swing
and
lower the
panel
in place
until it
engages
with the bottom
panel.
Turn the
screwhead
on
each
latch
clockwise.
The
screw
must turn
freely
one
quarter
turn before
resistance is
felt in
order for
the
lock to
engage. If
latch does
not
hold,
turn
screw
counter-clock-
wise
several turns
and
repeat the
above
procedure.
RIGGING
Rig unit
using
either
belt or cable
slings.
Use
spreader
bars
to protect
the top
of the
unit
when it is
lifted. See
fig-
ure 1.
On
units
with
a
total
length of
less
than 104"
(2642 mm),
excluding
evaporative
cooler,
two
holes are
provided in
the base
rail on each
side
of the
unit. Slide
pipes
beneath
the unit
through
these
holes and attach
rigging to
pipes for
lifting
the unit.
On
units with a
total
length of a
104"
(2642 mm)
or greater,
excluding evaporative
cooler,
lifting lugs
attached
to the
base
rail are
provided.
Attach
rigging to
lugs
for lifting
the
unit. For
distance
between
lifting lugs and
total
unit
lengths, refer
to
original
Submittal
Sheets
supplied
specified
for the
unit. Also see
Center of
Gravity and
Weights
Sections
in this
manual.
COMBUSTION
AIR
CONSIDERATIONS
The presence
of
chlorine
vapors or
other
corrosive
vapors
in the
combustion
air
supply
for gas-fired
heating equip-
ment
presents
a
potential
corrosive
hazard. Chlorine
will,
when exposed
to
flame,
precipitate
from the
compound
(usually freon
or degreaser
vapors) and
go
into solution
with any
condensation
that is
present in
the heat
exchang-
er or
associated parts.
The
result is
hydrochloric acid
which
will readily
attack all
metals,
including 300
grade
stainless
steel. Care
should be
taken
to
separate these
vapors
from the
combustion
process.
This may
be
done
by wise
location of the
unit
with regard
to
exhausters or
prevailing wind
direction.
LOCATION
Before placing
roofto p
unit in its
permanent
location,
make
certain that
the
roof is
capable
of
carrying
the additional
load
of this
equipment.
Check the
unit
weight given
at the
end of
this manual.
Refer to
Figure 2
for
required
clearances
to
combustible
material.
Figure 1
USE
SPRE A D
T O
PREVE
N
TI
T O U
N I
USE SPRE ADE R BAR
T O
PRE V E N T
DAMAGE
T O
UN IT
MOUNTING/
LOCATIONS
These
units
are
suitable for
installation
on
combustible
flooring.
Single,
double
and
triple duct furnace
only
models
have
base
rails which
can be
mounted
either
on
solid
planking
or
steel channels.
All other
units
installed
on
field
furnished
supports
must use
the
recommended
method
shown in
Mounting
on
Field
Furnished
Supports
or
equivalent.
Roof curb
kits for
rooftop
units are
shipped
unassembled.
Included
with the
roof
curb kit are
insulated
or
uninsulated
curb
rails,
bolts and
screws
needed
for
assembly,
sealant,
a
roll of
self-adhering
rubber
gasketing, and
installation
instructions.
Roof
insulation,
cant
stripping,
flashing,
roof
felts,
caulking,
and
nails
must be
furnished by
the
installer.
See
separate
roof curb
specifications.
II .
GENERAL
REQUIREMENTS
-3-

The venting is an integral
part of the unit and
must
not
be altered
in
the
field. The Natural Vented
units are
equipped with
a
ventcap which is designed
for natural
draft venting. Air for
combustion
enters the
base of the
vent
cap through
a
protective grill
and products of
com-
bustion are
discharged at
the upper section of the vent
cap.
CAUTION
: Insure
that all power
sources conform to
th
e un i t
requirements
or damage to the
unit may
result
Installation
must
be made in accordance with
local codes,
or in
the absence of local
codes, with the latest edition of
ANSI Standard
Z223.1 (N.F.P.A. No. 54) National
Fuel
Gas
Code.
All
of
the
AN SI
and N FPA Standards referred
to in
these installation
instructions
are
those that were
applicable
at the time the design
was certified.
The ANSI
Standards are
available from the American
Gas
Association,
1515 Wilson Blvd., Arlington,
Virginia 22209.
The
NFPA Standards
are available
from the N ational
Fire
Protection
Association,
Batterymarch Park,
Quincy, MA
02269.
If
installed in
Canada,
the installation must conform
with
local
building
codes, or in
the absence of local building
codes, with the
current
CAN/CGA-B149.1 or
B149.2
"Installation
Codes for
Gas
Burning Appliances
and
Equipment'.
T hese outdoor
duct furnaces
have been
designed
for
and certified to
comply with CAN/CGA
2.8.
These units
have
been designed
cert
i
f i ed
for
outdoor
u se only ,
and may
be located on the
roof of the building
or at
any
convenient location
external to
the building to
be
heated.
This
vent cap is shipped
in a separate carton and should
be installed
per the Venting section of the Outdoor
Rooftop
Gas-Fired Duct Furnace Installation
and
Service Manual.
The Power Vented unit has
a
induced
draft
venting
system.
The
combustion
air inlet and prod-
ucts of
combustion discharge grills
are
located
in the
upper section of the Duct
Furnace side access panel.
A pilot
burner plate is provided
in
the Duct
Furnace for
access to the pilot burner
and
ignition
system without
removing
the burner drawer.
Clearance between the
external
unit and any obstruction
must be sufficient for
proper servicing
of pull out burner drawer.
See
Figure
2
for this clearance.
These units
are certified for operation on either natural
or propane
gases. If
a
unit
is
to
be
installed
at an altitude
exceeding
2000 feet (610
m)
above
sea level, Berate the
unit input of
each duct furnace by 4% for each
1000
feet
(305 m) above sea level.
Special main burner gas orifices
are required
for installations above
2000 feet (610 m).
In Canada, if unit
is to
be
installed at altitudes
of 2000
feet (610 m) to 4500 feet
(1372 m), each duct furnace
must have the main
burners re-orificed to give
90% of
the
normal altitude input rating.
If the unit was
ordered from the factory
for high altitude
operation , confirm
input rating . See
Gas Input
Adjustment .
re 2A
,a
.
ow•
. 3 125
( 8 )
3 g
<.x)
-4-

Figure 2B
18"
(457
mm)
A
I
R FLOW
(45 7 mm)
Blower
c
0
U
0
U
U
W
Duct Furnace
I
Duct F urnace
D3 8 6 5
F*
"`
Refer
to Outdoor Duct Furnace Manual
for
spec
i
fic
clearances .
Supply Plenum
16"--
.
(457 mm)
If
a
single, double or triple duct furnace only
unit
is
III .
INSTALLATION
connected to
a
return air duct or any
other inlet air
restriction, the appliance shall be
installed
on
the
positive pressure
side of
the
air
circulating blower.
Installation
must conform with local building
codes
or in the absence
of
local codes with the
National
Fuel Gas Code ANSI
Z223 . 1
latest edi -
t i on
.
A heat
loss study and
a
complete layout
of
the sys-
tem
should
be made
first.
When
locating the unit in its permanent location,
make certain that the roof
is
capable of carrying the
additional load of
the
equipment. Check the unit net
weights section
of
this
manual .
Make certain that clearances are provided
for
ser-
vice,
minimum clearance to combustible material and
to
venting
cap. See figure 2 for
this
information.
Ducts
connected to units
which
do not have
either
a
blower
section
or a supply
plenum must have a
removable access panel in the
duct,
which is con-
nected to a duct furnace. The duct openings shall be
accessible when the unit
is
installed in service and
shall
be
of such size that
smoke or
reflected light
may be observed inside the casing to indicate the
presence of leaks in the heating element. The covers
for the panels shall be attached in such manner as to
prevent
leaks.
Ducts
exposed to
the outdoors
must
be insulated
and sealed
to
prevent
water
from enter-
ing either
the unit
or
building
through
the
duct.
CAUTION: Remove wooden shipping support
from beneath blower
housing
of
Blower Section
to prevent possible unit damage or improper
unit
operation (if applicable).
INSTALLATION
CLEARANCES
Minimum clearances to combustible
material are
shown on the unit data
plate. It
is
important that
clearances be maintained for
servicing the unit (refer
to Submittal Insert for service clearances),
and that
minimum clearances are provided
from the unit
(including
vent
cap, if
Natural Vent model)
to
com-
bustible material. Clearances around
the outside air
hood (if unit is so equipped)
must
be
unobstructed.
See Figure 2.
MOUNTING ON FIELD FURNISHED SUPPORTS
Single, double,
triple
duct furnace
only models have
base rails which
are
suitable for
mounting either
directly
on
solid planking or steel
channels. N ever
install the unit on a soft
roof where the rails could
sink, reducing clearance between the bottom
panel
and the roof, or cause damage to
the roofing surface.
All other models must use
the following method
or
an
equivalent when
unit supports are field
furnished:
Each
section of the Rooftop
unit must be
supported,
which includes supports located
at both ends.
If
the
unit consists of a High CFM
Blower section, a DX
Coil,
a
Duct Furnace and a
Supply Plenum, five sup-
ports are required.
See
Figure
3.
-5-

3
Suppo
rt m
us
t clear return
a i r o penin
g a n d f i t
Ins
i de
b ase rai l f la n g e .
See
Figures 4 & 13
for this dimension.
Support
must fit
inside base rail
f lang e s.
MOUNTING
ON
ROOF CURB
Assemble
and
install roof
curb per Roof
Curb
Installation
Instructions.
See Figures
4
&
13 for roof
opening sizes,
distance
between
openings and
unit
relationship
to
roof curb.
VENTINGt
All venting
installations shall
be in
accordance with
the
latest
edition of
Part
7 ,
"Venting
of Equipment", of
the National
Fuel
Gas
Code, ANSI
Z223.1-1992 (or
the
latest edition),
or
applicable provisions
of local
building
codes.
The
Natural
Vente
d u nits'... are equipped
with
a
vent
cap which
is designed
for
n
atural
draft venting. Air
for
combustion
enters the
base
of
the
vent
cap
through
a protective grill
and
produc t
s
of
combustion are
dis-
charged
at the
upper section
of the vent
cap. t Th i s
ve
nt
c a p i s
sh i pped in
a separate
carton and
s hould
be installed
per the Venting
section of the
Outdo
or
Rooftop
Gas - F i red
Duct Fu r na
c e
In s t a lla ti
on and
Service
Manual .
The Power
Vented
unit
has
a
induced
draft venting
system.
The
combustion
air inlet
and products
of
combustion
discharge
louvers are located
in the
upper section
of the
Duct Furnace side
access
panel. Never
locate these
units in an area
where the
flue
products
discharge
outlet
may be directed at
any
fresh
air
vents.
See the
Outdoor Rooftop Gas-Fired
Duct
Furnace
Installation
and Service
M anual for
installation
and
servicing requirements.
DUCTCONNECTIONS
All
ductwork
must be
properly
supported
so
that
no
strain
is
put
on the
unit. Do
not alter or
bend the dis-
charge
duct flanges supplied
on your
furnace/air
handler.
Ducts
connected to units
which do not have either
a
blower
section or
a supply plenum
must have
a
removable
access panel in the
duct which is con-
nected to
a duct furnace.
The duct openings
shall be
accessible
when the unit is installed
in service,
and
shall be of
such size that smoke
or reflected light
may be observed
inside the casing
to indicate the
presence of leaks
in the heating element.
The covers
for the
panels shall
be attached in
such a manner as
to prevent
leaks. Ducts exposed
to the outdoors
must
be insulated and
sealed to prevent water
from either
the
unit or building
through the duct.
If
a
single,
double or triple
duct furnace
only unit is
connected
to
a
return
air duct, or any other
inlet air
restriction, the
appliance shall
be installed on the
positive
pressure side of the
air circulating blower.
When
connecting
return air
duct
to
Standard or High
CFM
cabinets,
attach duct to return air
opening
flange
when
no dampers are
used. Otherwise, if
dampers are
used, attach return air
duct around col-
lar at bottom of
damper assembly. Also
refer to
the
Submittal Data
Sheets specified for your
unit.
When
connecting
supply air duct to Supply Plenum,
attach duct to
supply air opening flange
when no
dampers
are used. Otherwise,
if dampers are used,
attach supply air
duct around collar at bottom of
damper
assembly. Refer to the
Figure 13.
GAS PIPING
tt
All gas
piping must
be installed in accordance with
local
codes. It
is required that
a
ground union
be
installed
adjacent to
the gas valve of each duct fur-
nace,
and a ground union
be
installed just external
of
each duct furnace
for unit servicing. On vertical
runs,
a
drip leg
should
be provided upstream of any
con-
trol
manifold.
A gas shutoff valve should
be,
or may
be required
by local codes, installed upstream
of the
external
ground
union for
each duct furnace. A 1/8
inch
N.P.T. plugged
tapping,
accessible for test
gauge connection,
must be
installed
immediately
upstream
of the unit gas
supply connection.
tt
For complete
Gas Piping
installation, see
Outdoor
Rooftop
Gas-Fired Duct
Furnace
Installation
and Service
Manual.
It is
recommended that
the gas piping
not
be
installed through
the bottom
of the duct furnace
bot-
tom
panel. If piping
must penetrate
the duct furnace
bottom
panel, it
must be sealed to
prevent water
leakage.
Gas piping
must be installed
to allow
for removal of
burner
drawer for
unit
maintenance. Refer
to Figure 2.
-6-

Figure 4
CURB SPECIFICATIONS
* ROOF OPENINGS
UNIT TYPE UTJ "RT,
PVOrAH
"
CAPAC
I
TY DIMENSION
[ CA]
'
R E
TURN SUPPLY
26 00
AIR
B*
AIR
10/
1 5
(660)
OP
E
NING OPENING
37
. 00
20/25/50
(940)
30
/
35 /
60170 48
.
^
(1219)
40 / 80/12
53 .
50
(1359)
20 .
875
A*
20
.
875 ALL DIMENSIONS SHOWN HAVE BEEN
(530) (530)
CALCULATED
TO INCLUDE A ONE (1)
INCH
CLEARANCE AROUND RETURNAND SUPPLY
DUCTS .
** U
ROOFTOP
z
ARRANGEMENT
1
[RA]
LL
C,
E
J
J ^
z
L
UNIT
TYPE[
UTJ "AT
orPV"
UNIT
SPECIFICATIONS
(REFERENCES)
CAPACITY
BLOWER
COIL
SUPPLY
DIMENSION
[CA]
STD.
HIGH CFM
PLENUM A"
10 - 40
^
. J
50.85
(1292)
20 - 40
87.04
(2211)
10
-
40
113. 0 2
(2871)
UMT TYPE!
LIT)
AH "
BLOWER
[
R A I
[CA] ST
' D . HI COI
L SUPPLY
A
20 24 .
859
N,R
or
40
(631)
20 ^ . J
61
.
047
T
or
40 (1551)
W 20 . J ^ . J
87
.
035
or 40
(2211)
C
,
E
50 -80
76. 84
( 1
952)
113.02
J
M
5 0 - 80
(
2 871 )
139.01
L 50 -
80
(353
1 )
J ^
12
^
.^
1 39.01
(35 31
)
• '
ROO FT
OP
ARR
A NG
E ME NTS [ RA
] B, D ,
G,
K, M , P , S & U
ARE WITHOUT
A S
UPP
L Y P L EN U M ; U
SE
THE
SA
M E RE TUR N A IR D
IME
N
SIO
N
S F O R
THES
E
UNITS
R
OOFTO P O
PE N
I
N
GS. REFE R
TO
UN I
T SUB
M
I
TTA
LS
FO
R M OR E D E TA
IL.
UNIT
4 . 00
(102)
RUBBER
GASK ET
1
2 .
00
(3 0
5)
ROOF
U NI
T
BASE
RA
IL F
L
AN
GE
WI T H C URB CAP
1 . 00
NAI
L
NAILER
(WOOD STRIP)
CANT
FELT
DIMENSIONS ARE IN
INCHES
D I MENSIONS IN () ARE IN MM .
. 375 (10) CLEARANCE
SHOULD BE
MAINTAINED
ON EACH SIDE TO INSURE
PROPER INSTALLATION .
-7-

CAUTION : Do not over - tighten the inlet gas
pip-
ing at unit gas valve
or stresses
that
could
crack
the valve
may result .
The
gas
line
should be supported
so
that no strain is
placed on the unit.
Pipe
compounds which are not
soluble to liquid petroleum gases must be used on
threaded joints.
The appliance and its individual shutoff valve must
be disconnected from
the gas
supply piping system
during any pressure testing of that system at test
pressures
in excess of 1/2 psig (3.5 kPa).
The
appliance must
be isolated
from the
gas
supply
piping
system
by
closing the individual manual shut-
off
valve during
any pressure testing of
the
gas
sup-
ply piping
system at test pressures equal to or
less
than
1/2 psig
(3.5
kPa).
;
For
additional gas piping information, including
pipe
sizing and drip
leg installation, refer to
Outdoor
Rooftop Gas-Fired
Duct
Furnace
Installation
and
Service
Manual.
For
additional piping
information, refer to
the
National
Fuel
Gas Code
Z233.1
(latest edition).
NOTE : If
the
gas
duct furnace is to
be
fired with
LP
gas , consult local LP
gas dealer for
pip i ng
size
information
.
NOTE : UNIT INSTALLATION FOR USE WITH
PROPANE
(BOTTLED)
GAS MUST
BE MADE BY
A QUALIFIED
LP GAS DEALER OR
INSTALLER .
HE WILL
INSURE PROPER JOINT COMPOUNDS
ARE USED FOR
MAKING PIPE
CONNECTIONS
;
THAT AIR IS
PURGED
FROM
LINES
;
THAT A
THOROUGH
TEST
IS
MADE FOR LEAKS
BEFORE OPERATINGTHE UNIT ; AND THAT IT IS
PROPERLY CONNECTED
TO PROPANE GAS
SUPPLY
SYSTEM
.
Before
any
connection is made to an
existing line
supplying other gas appliances,
contact the local gas
company to make certain
that the existing line
is
of
adequate size to handle
the combined load.
Check all connections for leaks
with soap solution.
MODULATING GAS CONTROL
(OPT
I
ONAL) *
Mechanic
a
l :
On units
equipped
with
mechanical
modulating
gas
control,
the
temperature
sensing
bulb for the gas valve must be
field installed
in the
supply plenum. Carefully uncoil the
capillary tubing
to prevent kinking or sharp bends.
CAUTION: Do not
bend
the
capillary tubing with-
in
1/2"
(12.7
mm) of
the connection
to the bulb or
the valve. Repeated bending may
cause the tub-
ing
to leak or
break.
Center and fasten
the temperature sensing bulb in
the
supply duct
at least 2 inches below
the last duct
furnace section. See
Figure 5.
Figure
5
Electronic
:
On units (natural gas only)
equipped
with electronic modulating control, follow control
manufacturer's installation
instructions
for
sensing of
outlet air temperature.
* Also
refer
to
the Outdoor Duct Furnace
Installation Manual supplied with your unit.
-8-
Caution:
Do not rely on
a
gas shutoff valve to
iso-
late the
unit while conducting gas pressure/leak
tests. These valves may not
be
completely
shut-
off,
exposing
the
unit
gas
valve to excessive
pressure, resulting
in
damage.

ELECTRICAL
CONNECTIONS
All
electrical
connections
must
conform
to:
ANSI/NFPA No.
70-1993
(or latest
edition)
National
Electrical Code
and
applicable
local
codes.
In
Canada,
to the
Canadian
Electrical
Code,
Part I CSA
Standard
C22.1.
The
rooftop
packaged
unit is
wired
at the
factory
and
ready
to be
connected.
Actual
unit wiring
will
differ
according to
the options
chosen.
Each
furnace
is
shipped
with
its own
wiring
diagram;
refer
to
this
wiring
diagram for
all
electrical
connections
to
the
unit.
All
electrical
connections,
line
voltage
and
thermo-
stat, are made
in the
Electrical
Cabinet
(See
Figure
6).
Line voltage
connections
are made
at
the High
Voltage
Terminal
Block.
Thermostat
connections
are
made at
the
Main
Connection
Board
(See
figure
7).
CAUTION :
Do
not use any
tools
(i . e .
screwdriver ,
pliers
,
etc . )
across
terminals
to
check for
power .
Use
of a
voltmeter is
recommended .
Outdoor
line
voltage
conduits
leading
into the
unit
should be
installed to
prevent
rain
from
wetting
any
high
voltage
wire. Locate
the
thermostat
in
accor-
dance the
instructions
supplied
with
the thermostat.
All field
wiring
must
have a
minimum
temperature
rating of 85°
C (185°
F).
Thermostat
wiring
shall be a
minimum of
18 gauge
wire
size. See
the
following
charts for line
voltage
wire sizes.
Figure
6 . -
Standard
Blower
Cabinet
, Single
Duct
Furnace
with
Supply
Plenum &
Various
Options
Shown
1 . Mixed
Air
Controll e r
2 .
Return
Firestat
3 .
Econom
i zer
4 .
Filters
5.
Bl
o
w er M
otor
6 .
R e
verse
Air Flow
Sw i tch
7 .
Clog g ed F ilter
S
w itch
8 .
Hi gh V
oltag e B
arrier and
L am p
and C i
rcuit
Breaker
Mount
9 .
Main
Connect
i on
Board with
Fan
Time
Delay and
Function
Relays
10 .
Powe
r V e nt o
r
R
ela y
11 .
Freezestat
12 .
Supply
Fir es t a
t
13
.
Duct T h e
r
m
o s t a t
14.
Primary
Safety
Limit
15.
Power
Ventor
Motor
16.
Gas
Piping
Limit
17. Gas
Valve
18.
High
Limit
Safety
Switch
19.
Transformer
20. Electrical
Wiring
Inlet
21.
High
Voltage
Terminal
Block
22.
Door
Safety Switch
23. Contactor
24.
Centrifugal
Blower
25.
Damper
Motor
26.
Outside
and
Return
Dampers
27.
Enthalpy
Controlled
Economizer
-9-
Intake
Hood
Dampers/Filters
Electrical
Duc t
Supp l y
Blower
Cabinet Cabinet
F
urnace
Plenum

7
- Electrical
Cabinet
Low
Voltage
Sect
High
Voltag e Sec
I
L
Locate line voltage
disconnect box per local codes. If
mounting the disconnect box to
the
unit,
never
mount
it to
an
unit
access
panel.
Possible
locations include
the front of
the
blower or filter section, the outdoor air
hood
or the
rear of the supply plenum (See Figure 8).
Electrical
conduit must
be
routed so as not to
inter-
fere with
removal of any access
panel.
NOTE
:
Should
any or
i g
i nal wire suppl i ed
with the
unit hav
e to be replaced
,
it must
b ereplaced
w
i th
w
iri
ng
h
av i ng a
temp e rature r a
t
i ng
of
at least
105 °
C
(221 ° F) .
DX COIL EQU
I PPED UNITS (OPTIONAL)
See Coil Installation/Maintenance
Manual
for
Refrigerant Piping,
Liquid
and
Suction
Line
Components, Refrigerant
Charging
and Thermal
Expansion
Valve Adjustment. Remove
piping
plate
located
in lower corner next to filter section
and
cut
holes
in plate to allow suction
and liquid line pas-
sage. Provide
weatherproof seal around'suction
and
liquid lines
at
piping
plate when installed.
The DX Coil has
a 300
ft/min. (1.524
m/s)
minimum
and
a
600
ft/min. (3.048' m/s)
maximum
velocity
through
the coil requirement. This is
due
to preven-
tion
of coil icing or
condensate blow-off.
To
calculate
the
velocity
through
the coil, apply
the following for-
mula:
Velocity
Cooling Air
Flow
in CFM (m3/s)
through the
coil ^ Coil Surface Area in
ft2 (m2)
opt i
o
n
al
C
o
nt
rol
s
Jo
u
n ci
ng
Locat
io
n
1Q Back
Panel
OZ
main connection Board
Q High Voltage Barrier
Assy
O4
24V Transformer
Q5
High Voltage
Terminal Block
O8
Ground
Lug
O7 Din Mounting Rail
Contactor
or
Starter
1
D3 88 3
S - uisconnect
tJox vocations
Di s
conn e ct
9
D i scon n e c t
B o
x Located
On Int ake
E
n d Pane l
(Ret ur
n
A i r O nl y)
D
(acann e et
B ox Locat ed
On Out s id e
A ir Hood
iii
S U PP L Y AIR
Disconnect
Bo
x
Locat ed
On
Supply
Pl e
num End
Pan e l
D3-9-6-6
Condensate
Drain piping
must have a
P-trap
in
line
immediately
downstream of drain pan connection,
external to
the
unit, to prevent possible outside air
-10-

6 8 44 -101H -/
leakage into
unit. The P-trap
shall be of
sufficient dif-
ferential to
overcome
negative pressure of
the indoor
air blower.
A
minimum
height difference
of 2" is
required
(See
Figure 9).
Before
unit operation
begins, the
P-trap
must
be
primed
with either
water
(summer)
or glycol
(winter).
CHILLED
WATER
CO
I L
EQU I PP E D UN I TS (
OP TI
ONAL )
See
Coil
Installation/Maintenance
Manual
for
General Coil Piping
Recommendations. Remove
pip-
ing plate
located in the
near center
of the coil
cabinet
and
cut holes in
plate to
allow chilled
water
piping
passage.
Provide
weatherproof
seal around
chilled
water pipes at piping plate
when
installed.
Figure
9 - Drain
Pan
Connection
DRAIN PAN
CONNECTION
UNIT
2 "
MIN
.
D3Bb7
The
Chilled
Water
Coil has a
600 ft/min
(3.048 m/s)
maximum
velocity
through the
coil requirement. This
is due
to prevention
of condensate
blow-off.
To cal-
culate the velocity
through
the coil
apply the follow-
ing
formula:
Velocity
Cooling
Air Flow in
CFM (m3/s)
through
the coil
Coil
Surface Area in
ft2 (m2)
Condensate
Drain piping
must have a
P-trap in line
immediately
downstream of
drain pan
connection,
external to the
unit, to
prevent possible outside
air
leakage into
unit. The
P-trap shall be of
sufficient
dif-
ferential to overcome
negative
pressure of
the indoor
air blower. A
minimum
height difference
of 2" is
required (See
Figure
9).
Before unit
operation
begins, prime
P-trap with either
water
(summer) or
glycol (winter).
EVAPORATIVE
COOLER
EQUIPPED UNITS
(OPTIONAL)
Refer to
Evaporative
Cooler
Installation and
Service
Manual for
water and
electrical
connections.
IV .
OPERATION
GENERAL
INFORMATION
Refer to
Outdoor
Rooftop Gas-Fired
Duct Furnace
Installation and
Service
Manual for
specific
informa-
tion
regarding the
heating
operation of
this
unit.
All
units are
equipped
with
a
intermittent
ignition pilot
system. The
pilot is lit
and
extinguished
each cycle of
unit
heating operation.
Outlet
mu s t be
be
low u ni t
co nne c t ion
The
lockout
function
shuts off the
main and
pilot gas
valves
if the pilot
gas fails to
ignite
within 90
seconds
of the
onset of
trial for ignition.
In
order to
initiate
a
re-
ignition
trial, the power
supply
must be
interrupted
for
30
seconds.
The
gas
control system
operates
at 24
VAC and
is
supplied by a
stepdown
transformer
found in
the
electrical
cabinet that
will match the
unit
line voltage
specified. See
Figure 6
for unit
controls
location.
Do
not use a
thermostatic fan
control
switch
when
either
two-stage
firing or
modulated gas
controls
are
used.
NOTE :
Electronic
modulating
gas
controls
are
available on
natural gas
units
only . These
con-
trols are
not
ava
i
lable
with propane
units .
GAS
CONTROL
SYST E M
The
standard
unit comes
equipped
for
single stage
operation.
Unit
heating operation
is
accomplished
at
full input.
Each
duct furnace
is
equipped
with an
individual
igni-
tion control
system
which
consists of
the
following
components:
ignition
control module,
gas
valve and
pilot burner.
The
ignition
control
module is
the
heart of the
igni-
tion
control system.
This
control
initiates
all gas
flow,
provides
means
to light the
pilot
burner,
proves
and
monitors the
pilot burner
operation.
The gas
valve
consists of
two
operators
which pro-
vide gas
to the pilot
and main
burners.
Both
opera-
tors
are energized
and
de-energized
by
the
ignition
control
module each
heating
cycle.
On
natural gas
units, the
ignitor
will continue
to spark
and
pilot gas will
continue
to flow
until the
pilot flame
The
pilot
burner includes
an
ignitor
and flame
sense
is
proven.
probe.
The
ignitor
provides the
spark,
originating
at
the
ignition control
module,
to
light the pilot. The
igni-
LP (propane)
units are
equipped
with 100%
lockout.
tion
control module
proves
and
monitors
the
pilot
flame through
the flame
sensing
probe.
- 11 -

All
units follow
the
same basic
sequence of operation
and is
as follows:
1. Thermostat
calls for heat.
Power vented
units
only : D raftor
relay ener-
gizes
draftor
with call
for heat.
2.
Ignition
control
module energizes
pilot operator
of
gas valve
and initiates
spark at ignitor
of the pilot
burner.
3. Pilot
burner ignition
is
proven to the ignition
con-
trol
by the flame
sense
probe and
sparking of the
ignitor
is discontinued.
4. Once pilot
burner
operation is
proven, the ignition
control
module
energizes the
main
burner opera-
tor
of the
gas valve, allowing
gas
flow to the main
burners.
Po we
r v e nt
e d un i ts only
:
In
addition, draftor
operation
must
be proven
by draftor
end switch
before ignition
control
module
energizes
main
burner operator
of gas valve.
5. Approximately
60 seconds
after the
main burners
light the
fan time
delay
initiates fan
operation.
6. Thermostat
is satisfied
and call for
heat
is
removed.
Pow er v
e nted
units only :
Draftor
relay
de-ener-
gizes
draftor
with
removal of
call for heat.
7. Ignition
control
module
de-energizes
pilot
and
main
burner
operators
of
the
gas valve,
ceasing all
gas flow.
8. Approximately
two
minutes after
satisfying
the
thermostat,
fan
operation
ceases.
OPTIONAL
GASCONTROLS
These
units are
available with
optional
gas controls
which will
give
either
multi-stage
or modulating
oper-
ation.
The
sequence
of
operation
of those units
equipped
with these
optional gas
controls
differs only
at what
rate
each
duct furnace's
main
burners ignite
and
operate
at or the
order of duct
furnace firing
for
those
units
equipped
with two
or three
duct furnaces.
Two Stage
Units
: Two
stages of heating;
first stage
is 40%
of full
rate,
second
stage is 100%
of full rate.
Main burner
ignition
is at
first stage
only.
Th ree
St a ge
Units
: Triple duct
furnace
models
only.
Each
duct
furnace
is equipped
with
single stage
heating
but fired
independently,
giving
three stages.
Each
stage
is
33%
of the unit's
full input
rate. Duct
furnace
one will
always light
first and
disengage
last.
Four St
a ge
Un i ts
: Dual
duct furnace
models
only.
Each
duct
furnace
is
equipped with
two stage
heat-
ing
but fired
independently, giving four
stages. Each
stage is
25% of the units
full input rate. Duct
furnace
one will always
light first
and disengage last.
Six Stage
Un i ts
: Triple duct furnace
models only.
Each
duct furnace
is equipped with
two stage heat-
ing
but fired
independently giving
six stages. E
ach
stage
is 16.5%
of the units
full input rate. Duct
fur-
nace
one will always light
first and
disengage last.
Mechanical
Modulation Units
: These units
are
equipped
with
a
hydraulic
modulating control
which
provides
unit firing
capabilities
of
40 to
100% of the
units full
input rate.
This control is found in
the gas
train
downstream
of the gas valve and allows
main
burner ignition
only at the minimum
rate. A tempera-
ture sensing
bulb, located
in the discharge
airstream,
controls
the
level
of
modulation. These units
are
available with
a
modulation
bypass
which
will give
single stage
or full
input operation.
Electronic
Modulation
Units :
(Not available with
propane units)
These units
are equipped with
a elec-
tronic
modulating
control which provides
unit firing
capabilities
of 40
to 100% of the units
full input rate.
This
control is
found in the
gas train downstream
of
the gas
valve and allows
main burner ignition
only at
the
maximum
rate. A thermostat
with remote
setpoint
adjustment
modulates the
gas
input.
Multi - Stage
w / Electronic
Modulation
Units :( N ot
available with
propane units)
T hese
dual and triple
duct furnace
models are
equipped with an electronic
modulating control
on duct f urnace
one and single
or
two stage
heating
on each successive
duct
furnace.
Furnace
one
(modulated) will fire
first and disengage
last.
Additional
stages
of
heat
will engage
after fur-
nace one
has fired at
maximum modulation
capabili-
ty
for the duration
of the delay
setting. The amount
of modulation
and each
stage size
depends upon
unit size
and the
number of stages.
See following
chart.
Modulation Stage
Number
Capabilities
Size
of Stages
(% of full
Input)
(% of full
Input)
2
25
- 50 50
316.5
-
33
33
4
25
-50 25
6
16 .
5 - 33 16.5
AIR HANDLING
REQUIREMENTS
AND
ADJUSTMENTS
CAUTION
: Remove
wooden shipping support
from beneath
blower
housing
of Blower
Section
to prevent possible
unit
damage or
improper unit
operation
(if applicable)
.
-12-

Static Pressure
through the
unit should
never exceed
2.0"
W.C. (0.50 kPa).
The
standard
unit
is
operated at
a
temperature rise
range of
20 to 60 F° (11 to 33
CO).
The
high
temperature rise
model is
operated at
a
temperature rise
range
of
60
to 90 F° (33
to
50 CO).
NOTE : It
is important
that the final
temperature
leaving the unit does
not exceed 160 0
F
(71 °
C) .
When final
air
throughput adjustments
are being
made , a
check of
the discharge
air temperature
should be made
after unit has
operated
for 15 to
20
minutes
.
CAUTION : A
unit should
never be
allowed to
cycle on the
primary
limit for
a
prolonged period
of
time .
It is
a
safety
control to
prevent
a
fire . If
cycling on
the primary
limit is noted ,
corrective
measures should be
taken
immediately . Failure
to do so
could result in
unit damage
or
a
fire .
NOTE : At
initial unit
installation , unit
should be
started
momentarily to confirm
proper
blower
wheel rotation as
the unit will
deliver some
air
with the blower
wheel running
backwards .
Two basic air
control systems can be used
to deliver
conditioned air to the
occupied space:
intermittent or
constant fan operation.
Intermittent Fan
Operation : The unit employs
an air
control
system
which
utilizes a fan
time delay
relay to
operate the fan while heating
and the
thermostat
while cooling. Refer
to unit wiring
diagram.
Constant Fan
Operation:
The
unit can be
wired to
give an air control
system which
constantly
circulates
air through the
unit
and
occupied space
with
con-
stant
fan
operation. Refer
to unit wiring
diagram.
NOTE: Check blower belt
tension.
Proper belt
tension is important
to the long
life of
the belt
and motor. Proper
belt tension
will allow the
belt
to be depressed 1/2"
to 3/4".
It is
important that the
blower
motor and the
blower
wheel pulleys be in
good
alignment,
with the motor
and
blower shafts
parallel.
Belt tension
must
be
adjusted to give
approximately
3/4" deflection
of the
belt when
finger pressure
is
applied to the
middle of
the belt (See
Figure 10).
Small changes in
this
tension may be
necessary
for
optimum
operation.
Belts will
stretch over a
period of
time, requiring
an
adjustment
to this
tension. See
MAINTENANCE
section
for belt
and
pulley adjust=
ments.
These
units
are set at
the
factory for
the RPM
required
to meet
the air
volume (CFM)
and
external
static
pressure ordered.
If the
estimated
external
sta-
tic is
incorrect, or
changes were
made to
the duct
system,
the blower RPM
may need
to be
changed.
Both the
Standard and
High CFM
Blowers use
motors
which are
equipped with
adjustable
pitch pul-
leys.
After
removing belt(s),
loosen
the pulley
set
screw and
remove
the key, turn
adjustable
half of a
pulley clockwise
to increase RPM,
or
counter-clock-
wise
to decrease
RPM. Insert key,
tighten
set
screw
and
replace
belt(s). Adjust belt
tension
to
give 1/2"
to
3/4"
belt play
when depressed.
CAUTION :
Blower motor fu
l l load
amps
should
never b e
exc ee d e d .
Improper
un i t op e
r
a
t i on
or
motor failure
could result .
After
changing blower
RPM,
confirm blower
motor
full
load
amps
have not been
exceeded .
See
motor
data
plate for max i mum
full load amps .
L I GHT I NG
(Refer to
Outdoor Duct
Furnace
Manual for
all heat-
ing
functions
-
general
comments are
as
follows.)
Purge
the gas
line to the
unit of air
before attempting
to light the
pilot. Check for gas
leaks.
This unit is
equipped
with an
intermittent
ignition sys-
tem. A lighting
instruction is
attached
to the
unit. To
set the intermittent
ignition
system
into operation
proceed
as
follows:
1.
Turn on
the gas
valve(s) main
manual
valve.
2. Turn
on
electrical power. The
unit is
now
under
thermostat
control.
-13-

3.
Set
thermostat to highest level. This
will initiate
the
sequence of operation
detailed in the
Gas
Control
System section.
Check main burners for
operation.
4. Set thermostat
to lowest
level.
This will Interrupt
power to the ignition control
and shut off gas.
Confirm pilot
and main burners have
been
extin-
guished.
5. Set
the
thermostat
to the desired setting.
For complete
unit shutdown, proceed
as
follows:
1.
Turn off the
gas
valve(s)
main manual valve.
2. Set
thermostat to
lowest
setting.
3 . Shut off all electr
i
c
power
.
GAS INPUT
ADJUSTMENT
When
shipped from
the
factory,
all
equipped for the
average heat
content
which
is stamped
on the unit rating plate.
units are
of the
, gas
CAUTION
: Since the
heat ' cont
e
nt
of gas varies
by locality , the
input must
be checked after instal -
l ati
on of t he
un
i
t . If th e un i t i
s
ov
e rfired i t wi l l
shorten
the
life of the heat exchanger
. Never
exceed the input
on the rating plat
e.
For.
an accurate input rate
measurement the
follow-
ing meter
method should
be used to determine unit
input rate.
If
the
meter
method is not possible,
a
manifold pressure
check should
be made.
Meter Method
of Checking
Input Rate
1. Obtain
the heating value of the gas from the
local utility
or gas dealer.
This should be in units
of
Btu/ft3
(MJ/m3).
2. Determine
the
gas
flow
rate as shown in the
fol-
lowing
example.
EXAM PL
E :
Assume
this unit
has
a input rate of 250,000
B tu/hr (73.2 kW)
and
the heating
value
of the gas is 1 000 Btu/ft3 (37.3
MJ/m3).
Gas
250,000 Btu/hr (73.2
kW)
Flow
=
1000
Rate
Btu/ft3
(37.3 MJ/m3)
x 60
min/hr
= 4.17
ft3/min (1.974
Us)
Before determining
the
gas flow rate to
the unit,
all
other gas
appliances
connected to the same
meter
must be turned
off.
Fire
unit according
to instructions.
After
approximately
15 minutes of unit
operation,
determine
volume of gas used
in five minutes
of
3 .
4 .
5 .
unit operation.
For the Example above the unit
should use 4.17 ft3/min x
5
minor 20.8 ft3
(1.97
Us x 5 min x 60 s/min = 591 L) of gas. Minor
input adjustments can be made by removing
pressure
regulator cap and turning regulator
clockwise
to increase input or counter clockwise
to
decrease input. Any appreciable adjustment in
input rate should
be made by
reorificing.
Method
to Check Manifold Pressure
1. Close the manual valve
of
unit gas valve.
2.
Install
a'1/8" pipe connection
in
the tapped
hole
provided
in the gas valve body near outlet of the
valve.
3.
Attach
manometer to'1/8" pipe connection by
means of
a
rubber hose.
4.
Fire unit according to instructions and observe
the
pressure and confirm it matches the unit
manifold pressure
from
the unit rating plate.
5.
Small variations
in the
manifold pressure
can be
made
by
means
of the gas
valve pressure regu-
lator.
Remove pressure regulator cap and turn
regulator clockwise to increase pressure or
counter-clockwise to decrease pressure.
P I LOT ADJUSTMENT
1. Disconnect wire from terminal marked MV at
gas
valve.
2. Provide call for heat.
3.
Pilot
adjustment
is found on
the
gas
valve.
Remove
pilot adjustment
cap.
4. Adjust the pilot
screw to provide
properly sized
flame.
5.
A
proper pilot burner flame is a soft
steady
flame that
envelopes
3/8 to 1/2
inch (9.5
to
12.7
mm) of the flame sense
probe
tip.
6. Replace the pilot
adjustment
cap.
PR I MARY
AIR SHUTTER ADJUSTMENT
After the unit
has been in operation for at least 15
minutes,
adjust the primary air flow to
the burners.
Turn
the friction-locked manually rotated air shutters
clockwise to
close, counter clockwise to open. For
correct
air
adjustment, close the air
shutter until yel-
low tips
in the flame appear.
Then open
the air
shut-
ter
to the point just
beyond
the position
where yellow
tipping disappears.
CONTROLS
Primary
L
i mit
Control : The primary limit control
is
a
factory installed
component surface
mounted
in the
14-

inlet airstream at the
end of
the
heat exchanger.
When the
temperature reaches the limit setpoint,
normally
caused by
insufficient
air throughput, all
gas
is shutoff .
The
limit
control has an automatic
reset and once the unit
has cooled, it will reset itself .
This is
a
safety control and if cycling
on
the
primary
limit is noted, corrective action must be
taken. See
unit wiring diagram
for electrical location. This control
must never
be bypassed. Upon completion of unit
installation, the
primary limit must be checked for
proper operation.
This can be accomplished
by
\
removing
power
to the
indoor air blower and
a
call for
heat.
Draftor
End Switch : This switch is located
at
the
end
of the
draftor motor and is integral to the motor.
The switch,
whic h is normally
open,
will close when
draftor motor
attains the minimum speed for proper
combustion allowing main burner operation.
The
pilot
burner will light
without a proven draftor end switch.
See unit wiring diagram
for electrical location.
Clogged Filter Switch:
(Optional) The
clogged
filter
switch
monitors the pressure differential across the
air filters. If this
pressure
differential
becomes too
great, the switch will alert
of this condition. At this
point the air filters
must
either
be cleaned or
replaced.
The switch will reset itself.
Firestat: (Optional) Located
in either the return
airstream,
the supply airstream, or both, this control
monitors temperatures with setpoints
which are field
adjustable.
If the temperature exceeds the setpoint,
the
control will cease unit operation.
To resume unit
operation,
a manual reset of this control is required.
Freezestat: (Optional) Located in either the
return
airstream, the
supply
airstream,
or both, this control
monitors temperatures with setpoints which are field
adjustable.
If the temperature does not exceed the
setpoint, the
control will cease unit operation.
V.
START
UP
Before starting the unit, use the "Installation Check
Sheet"
(located at the
end of
this manual)
and read
the Outdoor
Duct
Furnace Manual entirely in
con-
junction with the procedures outlined below to
ensure that the unit is
completely
and properly
installed and ready for start up.
1. Inspect all wiring
connections; connections
should be clean and tight. Trace
circuits to
insure that actual wiring agrees with the "as
wired" diagrams provided with the unit.
Information in the wiring diagram title
block
should
match the data appearing on the unit
nameplate.
2. Lubricate
all
electrical motors according to the
manufacturer
' s recommendations
.
3. Verify that the system switch
is in the OFF position.
4.
Check
unit
supply voltage to ensure that it is
within the
utilization range.
5.
Inspect the
interior of the unit; remove
any
debris or tools which may
be
present.
Starting Unit in Heating
Mode
1 . Close the un
i t disconnect
switch
which provides
p owe r t o th e
u
nit .
3.
Place the system switch in the
ON
position.
With
the thermostat calling for heat, unit operation is
automatic.
Starting Unit
in Cooling Mode
1. Close the unit disconnect switch which
provides
power to the unit.
3.
Place the system switch in the ON
position.
With the
thermostat
calling for
cooling, unit operation
is automatic.
-15-
2. Set
the
thermostat/switching
subbase as
indicat-
ed below:
a.
position
the heating system
switch
at
either
HEAT
' or AUTO;
b :
set the fan
switch to AUTO.
2. Set the
thermostat/switching
subbase as
indicat-
ed below:
a.
position the cooling system switch at
either
COOL or AUTO;
b.
set the fan switch to AUTO.

Final
Checkout
Run
the
unit
sequentially
through its
stages
of heat-
ing
and
cooling.
Once proper
unit
operation
is veri-
fied,
perform
these final
steps:
1. Inspect
unit
for debris
and/or
misplaced
t ools
and
hardware.
2.
Be sure
all gas
valves
and controls
are
in the
operating
position
if
the unit
will be operating
immediately.
3. Cycle
unit
on all
safety controls
to verify
proper
unit
operation.
4.
Confirm proper
operating
control
(thermostat or
ductstat)
operation
by cycling
unit.
5.
Secure
all exterior
panels in place.
VI .
MAINTENANCE
nace; swing
downward the piping
to clear
drawer.
3. Disconnect
duct furnace
gas valve wiring taking
note
of all wire
locations.
Disconnect ignitor
and
flame
sensing
probe wires
at ignition
control
module
and any other
wires.
4.
Remove
the locking
screws
holding the burner-
drawer
assembly
in position.
5. Slide the
burner drawer
out of the
duct furnace.
6. Removal
of burners
is accomplished
by
sliding
burner towards
manifold,
compressing
locating
spring,
until the
rear of the
burner clears slot
in
back of burner
drawer.
7. With burner
drawer
removed
from duct
furnace,
inspect
the inside
surfaces
of
the
heat
exchang-
er. Wire
brush
if necessary.
8. Remove
any dirt,
dust or other
foreign matter
from
the burners
using
a wire brush and/or
com-
pressed air.
Insure
all parts of the
burner are
unobstructed.
Inspect
and
clean
pilot
burner if
necessary.
9.
Reassemble the
duct furnace by
replacing
all
parts in
order.
10. Light unit
per
the unit lighting
instructions.
These
units
have
been developed
for
outdoor instal-
lation.
Maintenance
is
required
and it
is suggested
that
the
following
unit
servicing
and
inspections
be
performed
routinely.
Also read
in entirety
and
refer to
the
Outdoor
Duct
Furnace
Manual for
maintenance
requirements.
Inspect
area near unit to
be sure that
there
is no
combustible
material
located
within
the minimum
clearance
requirements
(See
Figure 2).
Service
pan-
els provide
easy
access to
the gas
controls
(located
in
duct
furnace
section),
the
blower
compartment,
the
electrical
cabinet
and the
supply plenum.
To
remove
the
service
door
from
any of these
compart-
ments,
refer
to
access panel
removal
section in
beginning
of this
manual.
The pilot
burner
can
be serviced
by removing
the
pilot
plate
from the
main
burner
drawer
assembly.
To
remove
the
main
burner
drawer
assembly
(also
refer
to
Outdoor
Rooftop
Duct
Furnace
Installation
and
Service
Manual)
for
servicing
the
burners,
pro-
ceed
as follows:
1.
Shut off
the
gas
supply
at the
gas shutoff
valve
and
electrical
power
to the
unit.
2.
Break
the
union
upstream
of
duct
furnace
gas
valve
and loosen
the
union
external
to the
fur-
11. Check
the
burner adjustment.
See
the
"Primary
Air
Adjustment'
section
of this manual.
12. Check all gas
control
valves
and pipe connec-
tions for
leaks.
13.Check the
operation
of the
duct furnace
gas
valve
by
lowering the
setting
of
the thermostat,
stopping the
operation of the
duct furnace.
The
duct furnace
gas valve
should close,
extinguish-
ing the pilot
and
main burner flames.
14.
Inspect and service
the blower
section of
the
system.
The
unit should
be thoroughly
checked
before the start
and at the
end
of each heating
and cooling
season.
1. Motors
and belts
should
be inspected.
2.
Tighten
belts if
loose.
-16-