Honeywell L7248A,C,L, L7224A,C Wiring, Operation, Replacement Sensor Installation, Fuse, General

L7224A,C; L7248A,C,L OIL ELECTRONIC AQUASTAT® CONTROLLERS

SENSOR WIRES

BOILER

IMMERSION SENSOR

WELL

HEAT-CONDUCTIVE COMPOUND (OPTIONAL)

M22026

WIRING

WARNING

Electrical Shock Hazard.

Can cause serious injury or death.

Disconnect power supply before making wiring connections to prevent electrical shock or equipment damage.

All wiring must comply with local electrical codes and ordinances. Do not exceed the specifications in the Application section when wiring this control. Use wire rated for 194 °F (90 °C) or higher.

Fig. 4. Replacement sensor installation.

Replacement Sensor Installation

Turn off all power and:

1.	Carefully disconnect sensor from circuit board by
2.	pulling gently on the connector.
	Gently pull sensor from thermo well and through cir-
3.	cuit board by pulling on leadwires.
	Carefully align replacement sensor with hole in cir-
	cuit board and guide through Aquastat case and
4.	into well. (See Fig. 5).
	Make sure sensor is fully seated to bottom of well
	(See Fig. 4). Use a small pencil to measure depth of

IMPORTANT

The terminals on these Aquastat Controllers are approved for use with copper wire only.

Follow the appropriate wiring diagrams shown on the inside of the front cover of the L7224A,C; L7248A,C,L or in Fig. 8–13.

Refer to Fig. 6 for Connections for the optional Outdoor Reset Module and the Domestic Hot Water (DHW) module. In subsequent wiring diagrams these modules will be displayed with a dotted line signifying that they are optional.

5.	sensor in well, if necessary.
	Connect sensor to circuit board by pressing con-
	nector on sensor unit into mating connector on cir-
6.	cuit board (See Fig. 5).
	For remote sensors (flush-mounted Aquastat Con-
	trollers) be sure to use 121571AA Clamp (see
	Accessories) to securely hold sensor in place.

	THERMOSTAT		ENVIRACOMTM
	TERMINALS		TERMINALS
	T
	T	3
		2
		1	DISPLAY
ZR	LINE
L1
			SENSOR

	T
	T	3
		2
		1
ZR	LINE
L1
L2
C2
B2
C1
B1
ZC

50022037-002

OUTDOOR RESET MODULE

1 2 3 OT OT

C7089U1006

OUTDOOR

SENSOR

50022037-005

DOMESTIC HOT WATER MODULE

1 2 3 TS TS

32003971-003

TEMPERATURE SENSOR

M29651

L2	CONNECTOR
C2	RELAYS
B2
C1	SENSOR HOLES
B1
	FUSE
ZC
	M32187

Fig. 5. Circuit board, showing sensor connection and

well holes for vertical mount models.

Fuse

The 1 Amp fuse located near the transformer is intended to protect the EnviraCOM circuit from incorrect wiring. The Aquastat will continue to function should the fuse blow or be removed though no EnviraCOM communication will be possible on the bus and Err 6 will be displayed. See Table 10.

Fig. 6. Wiring the Outdoor Reset Module and the

Domestic Hot Water Module.

OPERATION

General

The L7224A,C and L7248A,C,L Oil Electronic Aquastat Controllers are primary safety limit-rated devices designed for use with oil fired boilers with line voltage burners and circulators. Many boilers do not include wiring or control compartments as part of the design, but are provided with an integral, replaceable, immersion well that is the mounting hardware for the Aquastat Controllers. Wiring to the other controls is done through flexible metal conduit.

For boilers that do include a remotely (flush) mounted control, the wiring may be completed with conduit or routed behind the boiler sheet metal.

68-0281EFS—05 4