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Combine photoelectric smoke sensing, 135 F heat detection, freeze trouble, and an 85 dB temporal sounder on a compatible two-wire circuit. -
Equip a compatible four-wire circuit with photoelectric smoke sensing, a 135 F thermal element, freeze trouble, and an 85 dB temporal sounder. -
Use mechanical heat detection where smoke sensing is unsuitable with a 135 F fixed threshold, restorable 15 F-per-minute rate-of-rise element, and 50 x 50 ft listed spacing.