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PFC 2000RC • 5403521-REV N• 3/03
TYPICAL 2-WIRE DETECTOR CONNECTION DRAWINGS
Base wiring for Hochiki models SIH-24F Ionization Detectors and SLK-24FH Photoelectric Detectors. See page 15 for instruc-
tions on selecting the Zone Style and Pre-Discharge Timer Activation Mode.
TYPICAL STYLE B (CLASS B) WIRING USING HSB-21, HSB-221 OR HSC-221R BASES
(These bases can be used in style B or Style D wiring)
TYPICAL STYLE D (CLASS A) WIRING USING YBA-M21 OR YBA-M221 BASES
(These bases can be used in style B or style D wiring)
Predischarge Timer
Relay
Activation Mode Selected
6" Dia. Base
4" Dia. Base
Impedance
Contact
1 or 2 (single or cross zone)
HSB-221N
YBA-M221
390 ohms
no
HSC-221R
390 ohms
yes
3 or 4 (sequential or cross
sequential)
HSB-221
YBA-M21
750 ohms
no
NOTES:
1) Only bases with 750 ohms of impedance can be used when sequential or cross-sequential timer activation is
selected. The 4" diameter bases will mount on a 3" octagon box. The 6" diameter bases will mount on a 3" or 4"
octagon box or a 4" square box.
2) When used in the sequential or cross-sequential mode, if an annunciator is to be connected to the smoke detectors
a 3.6K ohm resistor should be installed in series with the annunciator output. The LED should be capable of
illuminating at 2mA or less.
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