background image

Fire Initiating Devices and Notification Appliances Technical Manual

408

Conventional Products Section

Technical Bulletin

Issue Date

1095

©

1995 Johnson Controls, Inc.

1

Code No. LIT-408155

Introduction

Page

3

General Description

3

Installation Procedures

7

General Information

7

Mounting

7

Spacing

8

Wiring Installation Guidelines

8

Installation

9

Tamper-Proof Feature

10

Testing and Maintenance Procedures

11

Testing

11

Maintenance

13

Limitations of Smoke Detectors

15

Limitations of Sounders

16

2412AT, 2424AT, and 2424AIT

Direct 4-Wire Smoke Detectors

Summary of Contents for 2412AT

Page 1: ... LIT 408155 Introduction Page 3 General Description 3 Installation Procedures 7 General Information 7 Mounting 7 Spacing 8 Wiring Installation Guidelines 8 Installation 9 Tamper Proof Feature 10 Testing and Maintenance Procedures 11 Testing 11 Maintenance 13 Limitations of Smoke Detectors 15 Limitations of Sounders 16 2412AT 2424AT and 2424AIT Direct 4 Wire Smoke Detectors ...

Page 2: ...2 Conventional Products 2412AT 2424AT and 2424AIT Direct 4 Wire Smoke Detectors ...

Page 3: ...e model you are installing Before you install any 2412AT 2424AT and 2424AIT direct wire smoke detectors read and be familiar with System Sensor Guide for Proper Use of System Smoke Detectors Technical Bulletin in the Fire Initiating Devices and Notification Appliances Technical Manual FAN 408 that provides detailed information on detector spacing placement zoning wiring and special applications or...

Page 4: ...versed A Light Emitting Diode LED on each detector lights to provide a local alarm indication and will remain on when the supply polarity is reversed A screw terminal is provided for a remote LED annunciator optional accessory RA400Z These detectors are listed to UL 268 and are latching type system detectors The alarm can be reset only by momentary power interruption For testing these detectors ha...

Page 5: ...0TH 2 wire Photo Detector with Fixed Heat Sensor 12 24 VDC 120 µA 2400AT 2 wire Photo Detector with Fixed Heat Sensor and Horn 24 VDC 120 µA 67 mA 2400AIT 2 wire Photo Detector with Isolated Heat Sensor 24 VDC 120 µA 67 mA 2412AT 4 wire Photo Detector with Fixed Heat Sensor and Horn 24 VDC 120 µA 51 mA 2424AT 4 wire Photo Detector with Fixed Heat Sensor and Horn 24 VDC 120 µA 43 mA 2424AIT 4 wire ...

Page 6: ...imum interrupted tone when individual unit is in alarm or when the supply voltage is reversed Electrical Ratings 2412AT 2424AT or 2424AIT Operating Voltage 12 VDC 24 VDC Full wave Unfiltered Full wave Unfiltered Reset Voltage 0 73V 0 8V Standby Current 120 µA Maximum 120 µA Maximum Alarm Currents 51 mA 43 mA Reversed Supply 8 mA 15 mA Alarm is current limited Add 7 mA Maximum with RA400Z Remote An...

Page 7: ...unused wires exposed Each 2400 series detector is supplied with a mounting bracket kit that permits it to be mounted in either of two ways directly to a 3 or 4 inch 76 2 or 101 6 mm octagonal 1 1 2 inch 38 1 mm deep electrical box Figures 1 and 2 to a 4 inch 101 6 mm square electrical box using a plaster ring with the mounting bracket kit supplied flmount2 Figure 1 Flush Mounting of Detector on 4 ...

Page 8: ... be no smaller than No 18 American Wire Gauge AWG 1 0 square mm However the screws and clamping plate in the base can accommodate wire sizes up to No 12 AWG 3 3 square mm For best system performance the power and wires should be a twisted pair and installed in a separate grounded conduit or shielded cable to protect the IDC from extraneous electrical interference If a cable shield is provided the ...

Page 9: ...tectors have been installed apply power to the control unit 6 Test the detector as described in the Testing section of this technical bulletin 7 Reset the detector at the system control panel 8 Notify the proper authorities that the system is in operation Dust covers are an effective way to limit the entry of dust into smoke detector sensing chambers However they may not completely prevent airborn...

Page 10: ...e on the tamper proof tab located on the detector mounting bracket Figure 2 2 Install the detector To remove the detector from the bracket once the tamper proof feature has been activated 1 Depress the tamper proof tab located in the slot on the mounting bracket 2 Turn the detector counterclockwise for removal The tamper proof feature may be defeated by breaking and removing the plastic lever from...

Page 11: ...testing is complete notify the proper authorities the system is back in service testswc3 Test Module Socket LED Push recessed test switch with a 0 1 inch Max Diameter tool Recessed Test Switch Figure 5 Bottom and Side Views Showing Position of Test Switch Before testing the detector check for the presence of the flashing LED after the power is applied to the IDC or power circuit If it does not fla...

Page 12: ...ltmeter to check the detector sensitivity as described in the test module manual If the detector s sensitivity limits or the MOD400R limits do not appear on the back of the detector the MOD400R is not suitable for field sensitivity testing of that unit Aerosol Generator Gemini 501 1 Set the generator to represent 4 ft to 5 ft obscuration as described in the Gemini 501 manual 2 Using the bowl shape...

Page 13: ...er in the side slot of the detector cover 2 Twist it slightly until the cover can be turned counterclockwise for removal 3 Vacuum the screen carefully without removing it If further cleaning is required continue with Step 4 otherwise skip to Step 9 4 Remove the screen by pulling it straight out 5 Vacuum the inside 6 Clean the vaned chamber piece by vacuuming out dust and particles 7 To replace the...

Page 14: ...onventional Products 2412AT 2424AT and 2424AIT Direct 4 Wire Smoke Detectors covscr5 Removable Head Cover Cleanable Screen P N RS24T Test Slot Removal Slot Figure 6 Removal of Cover and Screen for Cleaning ...

Page 15: ...onization detectors offer broad range fire sensing capability but they are better at detecting fast flaming fires than slow smoldering fires Photoelectronic detectors sense smoldering fires better than flaming fires Because fires develop in different ways and are often unpredictable in their growth neither type of detector is always best and a given detector may not always provide warning of a fir...

Page 16: ...g alcoholic beverages The sounder may not be heard if it is placed in an area which is isolated by a closed door located on a different floor from the person in hazard or placed too far away to be heard over the ambient noise such as traffic air conditioners machinery or music appliances that may prevent alert persons from hearing the alarm The sounder may not be heard by persons who are hearing i...

Reviews: