506748−01
*P506748-01*
02/11
*2P0211*
Page 1
INSTALLATION INSTRUCTIONS LD4120 SMOKE DETECTOR REPLACEMENT KIT (73W51
& 73W52; LB−90945R & S) USED WITH SGA/SCA/LGB/LCB/LGE/LCE036−240 UNITS
Litho U.S.A.
506748−01
2/2011
Supersedes 506592−01
E
2011
LD4120 REPLACEMENT
SMOKE DETECTOR KIT
PACKAGED UNITS KITS
AND ACCESSORIES
Shipping and Packing List
Package 1 of 1 contains:
1− Smoke detector
3− Sampling tubes (two tubes on 73W52)
1− Smoke detector bracket
1− Sampling tube bracket (73W52 only)
1− Bag assembly containing:
1−Magnet
6−#10−16 X 5/8" screws
2−#8−32 X 1" screws
Application
The smoke detector replacement kit is used on
SGA/SCA/LGB/LCB/LGE/LCE036, 060, 120, 240, & 288
units. LD4120 replaces DH400 and DH100 smoke detectors.
73W51 is used in return air installations and 73W52 is used
in supply air installations.
Smoke detector will send a 24vac signal to the unit A55
IMC when smoke is sensed. IMC default mode will
de−energize unit. Some units will interrupt the main power
signal to the unit to de−energize the unit when smoke is
detected.
Installation
Refer to manufacturer’s instructions provided with smoke
detector.
Install Sampling Tubes
1− Install sampling and exhaust tubes in smoke detector
before installing smoke detector or bracket in unit.
The exhaust tube is packaged with the smoke
detector. See figure 1. Also refer to figure 2 and 3 for
supply air installations and figure 5 for return air
installations. Discard unused tubes.
Unit
Tube Length (in.)
Supply Air
Return Air
036/060
18
18
120
30
30
240
30
36
WARNING
Improper installation, adjustment, alteration, ser-
vice or maintenance can cause property damage,
personal injury or loss of life. Installation and ser-
vice must be performed by a qualified installer, ser-
vice agency or the gas supplier
SMOKE DETECTOR
FIGURE 1
SENSOR MODULE
COVER
POWER BOARD MODULE COVER
SENSOR HEAD
METAL
SAMPLING TUBE
POWER BOARD
EXHAUST TUBE
MAGNET TEST LOCATION
