Lochinvar LADDER DIAGRAM 399,999 - 750,000 BTU/HR MODELS, LBL20008 REV A, Schematic Diagram

Installation and

Service Manual

LADDER DIAGRAM 399,999 - 750,000 BTU/HR MODELS

LINE

120 VAC 15 AMPS

NEUTRAL

	60Hz	GROUND
BK		W

BL/ BK

	OPTIONAL
AUX. HI-LIMIT
		BR
	RESET				O .C.
		J1
PR		PR			24 VAC
		PR			LWCO
		P R		P R
					J 2
		1		2	3
		P	RESET GND

	PR			ALARM
				INPUT 3
MAN. RESET
					BL		~
							~
					T		~~
							~
				TEST		PROBE ~~
							~
	J3						~~
BL/			BL
BK	6	3		BL/
	5	2
O	4	1	Y	BK
		P R		BL	4	4
J4				O	5	5	PR
				P R	6	6

BL

ON/OFF

1

WARNING:

THIS

HEATER

MAY

BE

G

POWER

2

CONNECTED

TO ONE

OR

MORE

BRANCH

CIRCUIT BREAKER

+

SWITCH

CIRCUITS.

TO PREVENT ELECTRICAL SHOCK,

BL

BK

ENSURE

ALL

BRANCH

CIRCUITS

ARE

DE-

CHASSIS

ENERGIZED BEFORE ATTEMPTING TO SERVICE

24 VAC

120 VAC BK

GROUND

THIS EQUIPMENT.

CHASSIS

G

-

W

W

GROUND

Y

Y

Y

GND

Y	7	7	BL/	Y
BL	9	9		O
			BK
O

PR

BL

	Y	SILENCE	OPTIONAL ALARM
BL			BELL 24V OUTPUT

BL/BK	LOW	O/BK
HIGH
		O

PR PR ALARM

+	-
24	12
	HD-
	1

Y Y

Y

ALARM INPUTS 1, 2, & 3 JOIN HERE

	C	NO	BL		Y
			R	ALARM
PR	C		R	CONTACTS
		NO

OPTIONAL HIGH-LOW GAS		INPUT 1	BL
PRESSURE SWITCHES
ALARM	INTERMITTENT
INPUT 2
	ALARM ENABLE
	RELAY	HD#1
N.O.	C
		STAGE #1

	23
13	14
PUMP

PR AE BR

PR

INTERMITTENT

ALARM ENABLE

RELAY

PR

PR	TD	Y
OPTIONAL
CONTACTS
ANY FAILURE
PR	AL	Y
		NO

Y PUMP RELAY

	PU		Y
BR	NO	BK	TO POWER
	C		SOURCE
	PUMP	W

O/	PR
BK	PR/BK	1C 1NO
PR

R	HEAT		FLAME
			CURRENT
	2	DEM
			TEST PINS
		#1

-

+	BK
S1	F1

P C Y

OPTIONAL
ON BOILERS	BK
NC
	LOW BLOWER

CONTINUOUS INTERMITTENT
A1 A2	A3	B1 B2 B3
	P	O	PR/BK
			FLOW
		SWITCH

~~~

~~~

BL/BK

FIELD INSTALLED

SAFETY DEVICES

HD#2
STAGE #3
3C	3NO
O/BK
ALNMI ER	TRIPS
T

	RESET					GY
						GY
R/	OVERRIDE
		HEAT			TRIAL
O	3	DEM		IGNITER		GY
		#2
						GY
	15		16	O		O
				O		P
	STAGE #1				RESET
					PURGE	BL/W
		BL
						BL
					NO	T/W
					T
				C

5 4 3 2 1

11 10 9 8 7 6 5 4 3

LINE	F2
	-
NEU	+
	W
S2/
FS	IGNITION
TH	MODULE
PI	Y
24COM
RESET
24VAC	R
MV
PS

BK/W
W	STATUS
BK
OPTIONAL
RUN TIME
RELAY
CONTACTS
P
RT
P	P

C	BK/R	R	~~~~
	NO
		BK	W
	BK
		HIGH	W
			Y
			STAGE #1
	R		Y
	R

CONTINUOUS INTERMITTENT
A1 A2	A3	B1 B2	B3
OK		OK
	FAIL		FAIL
COM		COM

STAGE #2 2C 2NO STAGE #4

R/ BK

	PRESSURE		2	FF
			1
	SWITCH
17	R/BK
	18	OPTIONAL
STAGE #2				PR/BK
	BL	FFR

	C	NO	STAGE #2
		R/BK
			Y
R/BK		S2	Y
	STAGING RELAY

CONTINUOUSLY INTERMITTENTLY MONITORED MONITORED

NOTE: SHOWN WITH SHORTING

BARS REMOVED AND ATTACHED DEVICES IN NON-ALARM STATE.

EXAMPLE DEVICES:

4C 4NO

ALARM PR/ BK

BL

C	NO
	NC
C	NO

Y

P

PR

	R/BK
C	NO

R/O

STAGE #3 Y

HIGH/LOW GAS, AUX. HI-LIMIT
AUX. LIMITS , EXT. FLOW SWITCH				BL/BK
FIELD SUPPLIED LOUVER/
POWER VENTER CONNECTIONS
MOTOR	COM	CLOSED	PROVING
		OPEN
CONTACTS			SWITCH

19	R/O
	20
STAGE #3		5	PR
	PR
	BR/W	4	T/W
	BR	3	T
	W	2	W
	BK	1	BK

R/O	S3	Y
	STAGING RELAY
	THREE STAGE MODELS ONLY.
		W

	REMOVE
	JUMPER
GY	GY		PR
C2	NO2	BR/W IGN MOD - PS
	LE	BR	P-SW
		W	OPTIONAL LOUVER/
		VENTER CONTROL RELAY
		BK/W

TRONICELEC	TURERA ROLLE MPE CONTR TE	LOUVER PROVING
			CONNECTOR
SENSORS	8	BR	1	BR	BR
	9	W	2	BR	BR
				PR	PR
	7	PR	3	PR
	6	BR/W	4	BR/W	BR/W
	4	T	5	BR/W	BR/W
				BR/W	PR /BK
	5	PR/BK	6	PR/BK	PR /BK

		FIELD
		INSTALL AS
	INLET	NECESSARY
PR	OUTLET	OPTIONAL
	SYSTEM/TANK	BOILER ONLY
		O.A.
		SENSOR

ITEM	INDICATES
	JUNCTION POINT
(ELECTRICALLY SAME)
	LINES CROSS OVER
CLOSED END SPLICE
DIN RAIL CONNECTOR
	DOTTED LINE
INDICATES OPTIONAL
	EQUIPMENT
W = WHITE	T=TAN
BK = BLACK	Y=YELLOW
PR=PURPLE	BR=BROWN
BL=BLUE	G=GREEN
P=PINK	GY=GRAY
O=ORANGE	R=RED

R	= RELAYS LOCATED O N C ONTRO L
	PANEL

	EXAMPLE:
NOTES:	Y/G = YELLOW WITH GREEN STRIPE

(1)WHERE POSSIBLE, ALL SWITCHES AND CIRCUITRY ARE SHOWN IN THEIR AT REST STATES.

(2)ADDITION OF ENERGY MANAGEMENT SYSTEMS OR OPTIONAL LIMIT SWITCHES TO THE TERMINAL

R

=RELAYS LOCATED IN WIRING BO X

=LED S LO CATED O N DISPLAY BOARD

STRIP REQUIRE THE REMOVAL OF SOME OF THE SHORTING BARS FROM THE TERMINAL STRIP. (3) WHEN REPLACING DAMAGED WIRING, USE EQUIVALENT TYPE AND GAUGE.

=O PTIO NAL DIN RAIL CO NN ECTO RS LO CATED IN ELECTRICAL W IRIN G B OX .

SCHEMATIC DIAGRAM

SINGLE IGNITION MODULE UNIT

LBL20008 REV A

65