A.O. Smith 400 - 2100, Installation & Operation Manual

Page: 69 / 72

Installation & Operation Manual
11
Ladder diagram
(continued)
69
S2/FS
F2
F1
S1
NEU
11
-
+
-
+
IGNITION
MODULE
TH
10
RESET
7
24VAC 6
PS
4
3
LOW
HIGH
BLOWER
BK
R
W
R
MV
5
H/L
HIGH FIRE VALVE(S)
LOW FIRE VALVE(S)
W
LINE
W
Y
BK/
W
BK/
W
STATUS
2
O
HI-LIMIT
NC
C
AIR PRESS
SWITCH
IGNITER
TRIAL
MANUAL
RESET
8
24COM
9 PI
PURGE
RESET
R
GY
5
4
1
2
3
ALARM
BK
R
GY
BURNER
GROUND
HiGas
LoGas
R/BK
LOW
HIGH
T/W
O
O
T
GY
GY
WITCHES ARE SHOWN WITHOUT
WATER OR ELECTRICITY)
NIT. AS SUCH, SWITCH STATES
THOSE SHOWN ON DIAGRAM
WHETHER UTILITIES ARE
T CONDITION IS PRESENT. SEE
M FOR ADDITIONAL NOTES.
W
BL
1 4 3 2
R
Y
Y
Y
FACTORY
FLOW
SWITCH
AUX.
HI-LIMIT
NO
NC
C
O
O/BK O
~ ~ ~
~ ~ ~
C
NO
O
PR/BK
FF 1
T T/W
R/BK
1 2
1 2
1 2
1 2
HIGH/LOW FIRE RELAY
W
W
LOUVER
CONTACTS
LOUVER
PROVING
LV
LM
BR
BR
BK
LOUVER TERMINAL BLOCK
TO POWER
SOURCE
BK
W
PROVING
SWITCH
1 4 3 2
W
T/W
T
BK/
W
ARM
RUN
TD
C
NC
C
NC
NO
ARMING RELAY
RUN
TIME
DELAY
Y
Y
Y PR
BL
BL/W
O
Y
Y
R
T
1
2
3
4
5
1
2
3
4
5
SILENCING
SWITCH
ALARM
BELL
ALARM
CONTACTS
NO
C
RUN-TIME
CONTACTS
P
6 6
PR
PR/
BK
PR
BL
BL
2
1
2
1
Y
PR/BK
+
+
+
+
P
PR
PR
Y
PR
O
R
BL
LBL20332 REV B
BK
W
R
Y
TO PREVENT ELECTRICAL SHOCK
HIS HEATER MAY BE CONNECTED TO MORE THAN ONE BRANCH CIRCUIT . MORE THAN ONE
SCONNECT SWITCH MAY BE REQUIRED TO DE-ENERGIZE THE EQUIPMENT FOR SERVICING.
DANGER
!
(NOT ON 500)
G
O
O/BK
O/BK
1
2
O
1
2
O
LoGas