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Installation and
Service Manual
65
LADDER DIAGRAM 399,999 - 750,000 BTU/HR
MODELS
NC
N
C
NO
ALARM
I
NPUTS
1, 2, &
3
JOIN HE
RE
S2/
FS
-
+
F2
F1
NEU
LINE
S
1
O
R
P
RESSURE
SWITCH
R
ESET
PURGE
GY
GY
PUMP RELAY
B
K
STAGE
#2
STAGE
#1
1615
18
1
7
20
19
HEAT
DEM
#
1
ELECTRONIC
TEMPERA
TURE
CONTROLLER
O
P
TI
ONA
L
RUN TIME
RELAY
C
ONTACTS
LBL20008 REV A
24 VAC
1224
23
120 VAC
1
14
13
+
-
HD-
Y
Y
W
CHASSIS
GROUND
-
INTER
MITTENT
ALARM ENABL
E
REL
AY
Y
Y
2
N
O2C
1NO
1
C
3
N
O3C
BK/W
G
W
Y
O
PTIONA
L
CONTACT
S
ANY FAIL
UR
E
IGNITER
TRIAL
GY
GY
BK
P
O
O
BR
BR
W
CIRCUIT BREAKER
BL
+
A
LARM
CO
NTACTS
OPTIONAL
ALARM
BELL 24V
OU
TPUT
S
ILENCE
BL
G
BL
Y
A
1B
1
A
2A3 B2B3
CONTINUOUS INTERMITTENT
FLOW
SWITCH
O
Y
CHASSIS
GROUND
SENSORS
BK
1
2
BK
LARTUENENIL
GROUND
O/
BK
BL
S
TAGE #1
STAG
E
#3
Y
Y
Y
W
W
R
R/O
R/BK
BL
R
120 VAC 15 AMPS
60Hz
O/B
K
R/
B
K
Y
P
R
PR
Y
PR
BR/
W
BR
/W
B
R
BR
W
PR
PR
T
PR/BK
PR/BK
BR/W
B
R/W
BR/W
PR
/
BK
P
R/
B
K
BR
/
W
Y
Y
PROVING
SWITCH
MOTOR
CONTACTS
BK/W
ON/OFF
POWER
SWITCH
FIELD SUPPLIED
LOUVER/
POW
ER VEN
TER
C
ONNECTI
ON
S
(1) WHE
R
E
POSSI
BLE,
ALL SWITCHES AND
C
IRCUITRY ARE
S
HOWN IN THEIR
AT REST STATES.
NOTES
:
(2)
A
D
D
I
TION OF
EN
E
RGY MANAGEMENT SYSTEMS OR OPTIONAL LIMIT
S
W
ITCHE
S TO THE TERMINAL
ITEM INDICATES
CLOSED
END
SP
LI
CE
JUNCTION
P
O
I
NT
(
ELECTRICALLY SAME
)
T
=TAN
Y=YELLOW
BR=BROWN
G=GREE
N
GY=GRAY
W =
WHIT
E
BK
=
BLACK
PR=PU
R
P
LE
BL=
B
L
UE
P
=
PINK
O=ORANGE
(3)
WHEN
REPLACING DA
MAGED
WIRI
N
G, USE EQUIVALE
N
T TYPE AND GAUGE.
TD
P
P
BL/
BK
Y
PUMP
S
TA
G
E #2
STAGE #3
AE
PU
L
E
BL/W
OPTI
ONAL
LOUVER/
VE
NTER CONTROL RELAY
R
R
=
RE
LAYS L
OCATED O
N
CONTR
O
L
PANEL
=
RELAYS
LOCAT
ED IN WI
R
I
NG BOX
OPEN
CL
OSED
COM
C2
NO2
Y/
G
= YELLOW
WIT
H
GREEN STRIPE
R=RED
HD#1
H
D#2
ALAR
M
INPUT 1
PR
A1
B
1A
2A3 B2 B3
CONTINUOUSLY
M
ONIT
O
RED
INTE
R
MIT
T
E
N
TLY
M
ONIT
O
RED
FIELD INSTALLED
S
AFETY DEVI
C
ES
N
OTE:
SHOWN
WI
TH
SHORTING
BARS
REMOVED AND A
TTACHED
DEVI
C
E
S
IN NON
-ALARM
S
TATE.
CONT
INUOU
SINTERMI
TTENT
C
OM COM
F
A
I
L
OK O
K
F
A
I
L
H
IGH/LOW GAS, AUX.
H
I
-LIM
IT
AU
X. LIMI
TS
,
E
XT.
F
L
O
W SWI
TCH
EXAMPLE DEVICES:
BK
4
2
3
STAGE #1
S
TAGE #3
STAG
E
#2
PR
BR
1
2
6
5
4
3
O
U
TLET
B
R
BR
PR
PR
PR
24VAC
PI
RESET
PS
TH
24CO
M
M
V
1
2
4
5
6
7
8
9
1
1
3
1
0
-
+
STATUS
8
9
7
6
4
5
T/
W
Y
~
~
~
~
~
~
BL
T
ER
MIN
AL
S
TRIP
IGNIT
ION
MODULE
ALARM
INPUT 2
P
R/BK
P
R
P
B
L/
B
K
SYSTEM/TAN
K
O.A.
SE
NSOR
FLAME
CURRENT
TEST PINS
RT
BK
W
G
Y
G
Y
P
UMP
OPT
I
ONA
L
O
N
BO
I
LE
RS
BL
WARNING:
THIS HEATER MAY BE
CONNECTED TO ONE OR MORE BRANCH
CIRCUITS. TO PREVENT ELECTRICAL SHOCK,
ENSURE ALL
BRANCH CIRCUITS ARE DE-
ENERGIZED BEFORE ATTEMPTING TO SERVICE
THIS EQUIPMENT.
OPTIONA
L
BOI
L
ER
ON
LY
I
N
LET
R/BK
2
RESET
OVERRI
DE
3
H
EAT
DEM
#2
R
/
O
FIELD
I
N
STALL AS
NECESSARY
C
N.O.
R
EMOVE
J
UMPE
R
STRIP
R
EQUIRE THE
REM
OVAL
O
F SOME OF THE SHOR
TING BARS FROM THE
T
ERMINAL STRIP.
R
R
PR/BK
O
5
1
OPTIONAL
P
R
PR
AL
Y
P
Y
PR
PR
= LED
S
LOCATED ON DI
S
PLAY
BOARD
= OPTIONAL DI
N RAIL CONNE
CTO
RS
L
OCATED IN ELECTRI
CAL
W
IRIN
G BOX.
C
NO
PR
OPTIONAL HIGH-LOW G
A
S
PRESS
URE
S
W
ITCHES
PR
LOWH
I
GH
I
NT
ERMITT
E
NT
ALAR
M
ENABLE
RELAY
C
C
NO
NO
C
NO
NO
C
NO
P
4NO4C
STAGE #4
BL/B
K
S2
R/O
C
NO
Y
S3
C
NO
B
LOWER
W
~~~~
~~~~
B
K
LOW
C
R/BK
Y
R
R
BR/W
PR
B
R
I
G
N M
O
D - PS
P-SW
FF
PR/B
K
THREE
ST
AGE
MOD
ELS
ONLY
.
AUX. HI-LIMIT
PR
ALARM
INPUT 3
BL
OPTIONAL
MAN. RESET
BR
T
BL
PR
BR/
W
LOUVER PROVING
C
O
NNECTOR
R/BK
R/O
P
STA
G
ING RELAY
S
TAGI
N
G
RE
LAY
A
LARM
FFR
Y
B
L
PR/
B
K
N
O
C
BL
B
R
W
W
BK
PR
T
BK
T/W
W
BK/
R
BK
H
IGH
5
4
3
2
1
W
LINES C
R
O
SS
OVE
R
DOTTED
LI
NE
I
N
D
I
CATES OPTIONAL
EQUIPMENT
D
I
N R
A
I
L CONNECTOR
EX
AM
PL
E:
SCHEMATIC DIAGRAM
SI
NGLE IG
N
I
TI
O
N MODULE UNIT
C
BK
TO POWE
R
SOURCE
W
J3
5
4
6
1
2
3
O.C.
J1
J2
3
2
1
J4
P
GND
G
N
D
RESET
PR
T
PROBE
9
6
5
7
5
7
6
9
BL
O
PR
PR
4
4
BL
Y
Y
PR
BL/
BK
BL/
BK
BL
/
B
K
BL/BK
O/BK
RESET
~
~
~
~
~
~
~
~
~
~
~
~
Y
O
PR
O
O
PR
BL
PR
24 VAC
LWCO
PR
TEST