Architectural/Engineering Specifications

The air duct detector shall be a System Sensor model 2451 Series Smoke detector UL listed to UL 268A specifically for use in

air handling systems when used in conjunction with the B404B (120VAC) or the B404BT (24VAC/DC) base. The detector shall

operate at air velocities up to 3000 feet per minute. It shall be capable of local testing via magnetic switch or remote testing

using the UL listed RTC Remote Test Coil accessory with the RTS451 Remote Test Station. It shall be capable of providing

duct smoke detector status via the UL listed model APA451 Piezo Annunciator.

Wiring Guide

B404B Typical Wiring Diagrams:

RA400Z

(Optional)

RA400Z

(Optional)

RELEASING

DEVICE

POWER

RELEASING

DEVICE

POWER

1

6

7

8 9

10

11

12

13

14

2

3

4

5

RELEASING

DEVICE

1

6

7

8 9

10

11

12

13

14

2

3

4

5

EOL

FIRE

ALARM

CONTROL

PANEL

ALARM INITIATION LOOP

SPECIFIED

BY PANEL

MANUFACTURER

BLACK LEADS

TRANSFORMER

PRIMARY

120 VAC

120 VAC

(+)

(–)

(+)

(–)

RA400Z

(Optional)

FAN/DAMPER

CONTROL

POWER

1

6

7

8

9

10

11

12

13

14

2

3

4

5

EOL

FIRE

ALARM

CONTROL

PANEL

ALARM INITIATION LOOP

SPECIFIED

BY PANEL

MANUFACTURER

BLACK LEADS

TRANSFORMER

PRIMARY

120 VAC

No.

Function

1

Remote Annunciator (+)

2

Not Used

3

Not Used

4

Remote Annunciator (-)

5

Not Used

6

N.O.

Supervisory Relay

Form A Contacts

7

N.O.

8

N.O.

Alarm Relay

Form A

Initiation Contacts

9

N.O.

10

C.

11

C.

12

N.O.

Alarm Relay

Form C

Auxiliary Contacts

13

N.C.

14

C.

B404B Base Terminals

Base

Model

Version

Loop Type

Current Limit

resistor

Alarm Contact Type

Nominal Voltage

Alarm Current

(mA)

B404B

UL/ULC

4-wire

Yes

Form A&C + A supy.

120VAC

20.4

B404BT

UL

4-wire

Yes

Form A&C + A supy.

24VAC/DC rms

94

Base Chart

Junction Box Selection

Base Model

Single Gang

4˝ Oct.

4˝ Sq.

50mm 60mm 75mm

B404B

No

No

Yes

Yes

No

No

No

B404BT

No

No

Yes

Yes

No

No

No

H0270-00

H0271-00